Pandemic Survival Guide

Swine Influenza

Swine Influenza

SWINE INFLUENZA frightening you? CONCERNED about the health implications? Coughs and Sneezes Spread Diseases! Stop The Swine Flu from Spreading. Follow the advice to keep your family and friends safe from this virus and not become another victim. These simple cost free guidelines will help you to protect yourself from the swine flu.

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Pandemic Shield Ebola Survival Plan

Pandemic Shield is an ultimate preppers guide to outbreaks and how to survive them. You will learn how past pandemics have affected our world and what you can do in case of an outbreak. You can use this clear and precise survival guide to: Prepare for the new plague, know the real truth behind the Ebola pandemic. Get your home ready for lockdown. in case of crisis learn how to prep your home for a pandemic. This extensive survival guide section will show you how to prepare your home for any crisis. what to do if the medical system fails. how to treat illness at home.gathering food and water supplies and first aid preparation among others. You will also discover how you can begin to prepare before it is even too late. with natural immune boosting strategies and ways to prevent illness. The threat of an Ebola outbreak is real and right here on your doorstep. It is only a matter of time before it affects you and those you care about and the authorities are doing nothing about it. With Pandemic Shield you will literally be ready for anything. from disease to social and economical breakdown. Whether or not the Ebola threat becomes a pandemic, this is an urgent reminder that we need to prepare ourselves and our families for any possible disaster.

Pandemic Shield Ebola Survival Plan Summary


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Strategies for Reducing Secondary Pneumonia Caused by Resistant Bacteria during a Pandemic

Several strategies might reduce the burden of antimicrobial resistant secondary bacterial pneumonia during a pandemic. Strategies aimed at reducing the incidence of influenza infection could markedly reduce episodes of secondary bacterial pneumonia. These include use of antiviral agents, influenza vaccines and social distancing measures. There is also some evidence to support strategies that could limit unnecessary antibiotic use even when prior influenza infection is suspected. Previous pandemics suggest that patients who appear relatively well and do not have significant findings on chest radiographs will not benefit from antibiotics 71 . Although clinicians over-prescribe antibiotics for patients with clinical signs of pneumonia 100 , results of radiographs, when provided to clinicians, can reduce antibiotic use among patients suspected of having pneumonia from 43 to 17 101 . 112 . Regardless, pneumococcal polysaccharide vaccine has been shown to have 50-80 effectiveness against...

Sars Coronavirus Proteases

The SARS-CoV replicase is encoded in the 5'-most 21 kb of the 29.7kb viral genomic RNA. The genomic RNA is translated to produce two replicase polyproteins, termed ppla and pplab 6,7 . The ppla is a 486 kilodalton (kDa) polyprotein that is predicted to contain a single papain-like protease (PLpro) analogous to the second murine coronavirus PLpro domain, a picornavirus 3C-like protease domain (3CLpro, also sometimes noted as Mpro or main protease), three putative membrane proteins, and several additional products of unknown function. The pplab ( 790 kDa) is generated by ribosomal frameshifting and extends the ppla product to include open reading frame lb, which contains the core RNA poly-merase and helical domains, and additional products of unknown function. The ppla and pplab polyproteins are predicted to be processed to generate l6 protein products (termed non-structural proteins, nspl-nspl6) 8 , which assemble to form a membrane-associated viral replication complex.

Sarscov 3clpro Inhibitors

Proteolytic processing of the coronavirus replicase polyproteins is essential for ongoing viral RNA synthesis. Therefore, the SARS-CoV proteases are attractive targets for the development of antiviral drugs to reduce viral replication and pathogenicity. The structure and activity of the coronavirus 3CLpro has already been elucidated and the design of inhibitors to 3CLpro as therapeutics has been proposed 9,10 . SARS-CoV 3CLpro has three domains I (residues 8-101), II (residues 102-184), and III (residues 201-301). Domains I and II, which contain the active site region, are p-barrel domains and III is an a-helical domain. In the active site, a cysteine residue (Cys-145) acts as a nucleophile and a histidine residue (His-41) acts as the general acid base. The X-ray crystal structure of the related enzyme from porcine transmissible gastroenteritis coronavirus (TGEV 3CLpro) and a substrate-analogue hexapeptidyl chloromethyl ketone (CMK) inhibitor 1 (Cbz-Val-Asn-Ser-Thr-Leu-Gln-CMK) has...

Covalent inhibitors of SARSCoV 3CLpro

The design and synthesis of two analogues (3,4) of AG7088 (2) was recently reported 13 . Based upon the reported SARS-CoV 3CLpro structure 9,14 , AG7088 was modified by changing the P2 side chain from a -fluorobenzyl group to the smaller benzyl and prenyl groups. These inhibitors possess a P1 P1'- a,p-unsaturated ester functionality, which can covalently link to the Cys-145. Compound 2 is inactive against SARS-CoV in cell-culture assay. The antiviral activity for 2 was reported to be 100 mg ml 15 . The modified analogues are not only potent against SARS-CoV 3CLpro (kinact values), but are effective in a SARS-CoV cell assay (IC50 values) as well. No toxicity was observed up to 100 mM. Moreover, an X-ray crystal structure of the SARS-CoV 3CLpro covalently linked with the synthetic small molecule inhibitor (4) was reported. In addition to the important covalent bond formed between 4 and the protease, the X-ray structure also showed crucial hydrogen bonding between 4 and His-164 and...

Noncovalent SARSCoV 3CLpro inhibitors

A series of synthetic small molecule, non-covalent inhibitors of SARS-CoV 3CLpro was published in 2004 21 . These investigators previously reported that keto-glutamine analogues with the phthalhydrazido group at a-position are reversible inhibitors of hepatitis A virus (HAV) 3C proteinase. The IC50 values of the inhibitors were in the low micromolar range 22,23 . They synthesized a series of keto-glutamine analogues with the phthalhydrazido group at the a-position and attachment of tripeptide (Ac-Val-Thr-Leu) as the inhibitors (7-14) for SARS-CoV 3CLpro. The combined effect of the p and p' amino groups adjacent to the keto group and intramolecular hydrogen bonding to the carbonyl makes it more elect-rophilic. As a result, the carbonyl group can form a hemithioacetal with the sulfur of Cys-145. The K values of these reversible inhibitors remain to be determined. A diversified library of peptide anilides was prepared and their inhibitory activity was examined against the SARS-CoV 3CLpro...

Antibiotics May Play an Important Role in Pandemic Influenza

Strategies to counteract pandemic influenza depend largely on vaccine deployment, just as they do with seasonal flu. As of late 2009, no accepted vaccine for influenza H5N1 was widely available. (A vaccine had been made, but it was in short supply and was untested with human populations.) Vaccine makers were unsure which viral substrain to use for production. As pointed out, 6 months are required to prepare, test, and distribute a vaccine 238 consequently, our control over pandemic influenza has a serious time lag. Quarantine and isolation can help cover the vulnerable time, but disruption to society could be enormous if even a small fraction of people stayed home from their jobs. It is likely that anti-influenza drugs will be needed. Both the adamantanes and the neuraminidase inhibitors limit infection by susceptible influenza viruses if used early in infection. Late in infection, when the body reacts to the virus with flu-like symptoms (respiratory discomfort, fever, aches, and...

Box 112 Spread of Adamantane Resistant Avian Flu Virus H5N1

Neuraminidase-mediated resistance tends to emerge from point mutations.232 With oseltamivir and avian influenza virus, resistance following treatment has been attributed to conversion of histidine-274 to tyrosine. (This amino acid substitution fails to affect zanamivir treatment.231) As the virus evolves in birds, antibiotic susceptibility changes in complex ways due to the evolution of the target protein and other interacting proteins. That complexity can cause virus isolates from different times and different geographic locations to differ in drug susceptibility, which makes antibiotic resistance in avian flu difficult to describe in a simple way. If avian flu causes a human pandemic, the problem of antiviral resistance will be exacerbated by arming citizens with oseltamivir and asking them to prophylax The public cannot be expected to always get the timing and dosing right. When resistant virus emerges from infected persons taking antibiotic, those strains are likely to spread, as...

SARS CoV inhibitors SRMLSC

Researchers at SRMLSC recently developed a HTS that allowed the identification of potential inhibitors of the severe acute respiratory syndrome Coronavirus (SARS CoV) from large compound libraries 34 . The luminescent-based assay, which measured the inhibition of SARS CoV-induced cytopathic effects (CPE) in Vero E6 cells, was validated with two different diversity sets of compounds against the SARS CoV. The hit rate for both libraries was approximately 0.01 . The validated HTS assay was then employed to screen a 100,000-compound library against SARS CoV. The hit rate for the library in a single-dose format was determined to be approximately 0.8 . Screening of the three libraries resulted in the identification of several novel compounds that effectively inhibited the CPE of SARS CoV in vitro. Three hit compounds, shown below, were identified as promising lead candidates for further evaluation.

Evaluation of the Immune Pathogenesis of Human SARS Using Multiplexed Bead Based Flow Cytometric Assays

Severe acute respiratory syndrome (SARS) is a highly contagious respiratory disease caused by the newly identified SARS coronavirus (SARS CoV) that emerged in late 2002 from Guangdong Province, China (CDC Update, 2003 Peiris et al., 2004 Skowronski et al. 2005). SARS has infected more then 8400 persons worldwide to date, killing more than 10 of patients. Those infected with SARS suffer fever, cough, muscle aches, and shortness of breath and often progress to severe lung inflammation. Most patients recover from this illness within 2 weeks, however a large percentage of SARS patients develop severe complications. Although the SARS outbreak of 2003 was largely contained through public health measures, it is clear that the future threat of similar emergent viruses or other microbial agents causing severe respiratory disease will not easily be eliminated. SARS CoV infection appears to be hallmarked by a poorly defined cytokine storm in the lungs and circulatory system of SARS patients...

Avian Flu H5N1 Is a Candidate for Deadly Pandemic

Since 2003, avian flu has received considerable attention as a potential pandemic virus. This version of influenza A, caused by subtype H5N1, is endemic to Southeast Asia. In the late 1990s, it began its worldwide spread via birds, and between 2003 and September 2008 it caused 387 documented human deaths.232 The human death toll was small, largely because transmission of virus occurred from bird to human rather than from human to human. The unsettling number was the crude mortality rate a staggering 63 .232 Flu experts expect the mortality rate to drop considerably when the avian flu virus adapts to human-to-human transmission, but how much is unknown. In 2008, the H5N1 virus was still spreading effectively among birds, and infection of humans required exposure to high inocula.

Relationship Between Past and Future Pandemics

Given what we know about previous pandemics, a key challenge is to ensure that all patients with secondary bacterial pneumonia are treated appropriately with antibiotics while minimizing the inevitable consequences of promoting antibiotic resistance. By comparing previous pandemics to what might be expected from the next one, it might be possible to identify those questions which, if answered, could aid in preventing cases of secondary bacterial pneumonia, including those resistant to antibiotics. Similar to the 1968 pandemic, when antibiotics were widely available, we can expect that most patients with any evidence of CAP during a pandemic will be treated with antibiotics. We can also expect that there will be shortages of vaccines, antiviral and antibacterial agents, diagnostic test reagents and hospital beds 73, 74 . Anticipating these shortages as much as possible, preventing them and providing guidance on how to best manage patients during shortages are all critical steps for...

Antibiotic Resistance Occurs with Avian Flu H5N1

Strategic use of antiviral agents requires that a pandemic virus be susceptible to existing antiviral drugs. Susceptibility may be true at the beginning of an outbreak, but it cannot be known in advance because the pandemic virus is unknown. The government plan also assumes that the virus will remain susceptible to the drugs during widespread use. Given what we know about influenza viruses, this is problematic. Adamantane resistance has been developing for several years (see Box 11-2), as these drugs have been used prophylactically with poultry in China.232 By 2007, 30 of the avian flu isolates were resistant to the adamandanes,232 making the agents unlikely to be useful in a pandemic. In 2009, the neuraminidase inhibitors were the only option if avian flu had started to spread among human populations.231

SARSCoV 3CLpro inhibitors from screening

Extensive screening has been carried out in an effort to find structural leads against SARS-CoV 3CLpro from existing drugs. A major advantage is that approved drugs with minimal modifications may have the possibility of gaining accelerated approval by US Food and Drug Administration. It was reported that Kaletra, a mixture of protease inhibitors - Lopinavir and Ritonavir, approved for treating HIV in 2000, shows some effectiveness against the SARS virus 30 . Based on this observation, the binding affinities of six other drugs were investigated against SARS-CoV 3CLpro 31 . These include Lopinavir, Ritonavir, Niclosamide, Promazine and two other HIV inhibitors, PNU and UC2. The preliminary results indicated that these drugs could be useful as templates for designing SARS-protease inhibitors 32 . A collection of nearly 10,000 synthetic compounds and natural products was screened in an assay using SARS-CoV and Vero E6 cells 6,33 . For the SARS-CoV 3CLpro inhibiton assay, a C2-symmetric...

Pandemic Influenza Can Be a Killer

A pandemic is an outbreak that spreads to multiple countries. The Spanish Flu pandemic of 1918-19 killed at least 40 million people worldwide within a 12-month period more than 500,000 deaths occurred in the United States. An initial wave in the spring and early summer of 1918 was mild, whereas the second, in the fall of 1918, was severe. A third, less severe wave occurred in the winter and spring of 1919.229 Flu victims were not limited to the old and infirm Members of the healthiest age group, 15- to 34-year-olds, died in staggering numbers. Indeed, killing young adults seemed to be characteristic of the 1918-19 flu.237 Smaller flu pandemics have also occurred. The 1957-58 Asian Flu killed nearly 1.5 million people worldwide, and the 1968-69 Hong Kong Flu had nearly 1 million victims. In 2009, a pandemic H1N1 strain originated from pigs in Mexico. To avoid embarrassment to Mexico, the pandemic was commonly called H1N1 Flu, which was confusing because much of the seasonal flu was...

Prevention Of Infectious Diseases

Acquired in a hospital OUTBREAK A larger than normal number of diseased or infected individuals that occurs over a relatively short period PANDEMIC An epidemic that spans the world RESERVOIR Origin of tine etiologic agent or location from which they disseminate (e.g., water, food, insects, animals, other humans)

Background And Context

The HIV pandemic is arguably the most compelling public health crisis of the post-World War II generation. In the post-World War II era, infectious diseases were on the wane. Common bacterial infections were readily treated with available antibiotics ubiquitous childhood diseases (e.g. polio, measles, mumps) were preventable with vaccination even the scourge of smallpox was eradicated worldwide. The epidemiology and clinical management of chronic diseases such as heart disease and cancers and an emerging interest in environmental health were ascendant public health priorities. Many warning signs of the potential for the emergence or re-emergence of great pandemics caused by infectious agents were accumulating during the latter half of the twentieth century increasing population pressures, migration and urbanization, political or social upheaval, and especially in western countries, the sexual revolution and drug-culture. Emerging from obscure African origins, HIV was introduced into...

What infectious diseases can be contracted from a transfusion and how significant is that risk

However, there are new infectious risks, including contracting prion-mediated diseases (variant Creutzfeldt-Jakob disease (vCJD), parasitic disease (Chagas disease, malaria), and avian flu. There are concerns that severe acute respiratory syndrome will eventually be spread through the blood supply. The risks of these diseases vary with the geographic locality. For instance, malaria is a greater risk in undeveloped countries (as is HIV) the only known cases of contraction of vCJD through transfusion are in the United Kingdom.

The Nature Of Virus Reservoirs

Since viruses must replicate to survive, actively infected populations are the usual source of infection. Still, some viruses such as poxviruses and SARS virus have a high resistance to desiccation. In this case a contaminated object such as a desk, pen, book, contaminated clothing, or other inanimate object can be identified as the immediate reservoir. The last documented cases of smallpox in Somalia were apparently acquired from contaminated soil. The persistence of some viruses in fecal material is also a potential long-lasting, essentially passive, reservoir of infection. Aerosols of infectious Hantavirus and canine parvovirus can be infectious for many months after secretion. Also, some viruses, especially hepatitis A virus, can be isolated from contaminated water sources for several days or even weeks after inoculation. Ebola Civet cat (for SARS CoV) Colds SARS In large populations the rate of virus spread greatly surpasses the limitations of the generation of herd immunity and...

Resistance Containment

The evidence is insufficient but points to higher rates of resistance in developing countries. Moreover the rate at which resistance is rising appears to be faster in developing countries (Okeke et al. 2000 Zhang et al. 2006). Therefore although resistance containment interventions have mostly been implemented in northern Europe and North America, there is a more pressing need to intervene in the resistance pandemic in developing countries.

Relenza And Tamiflu Inhibitors Of Influenza A And B Neuraminidase

Both drugs bind to a group of 11 or so amino acids in the active site of the NA enzyme. These amino acids are constant in all current influenza A and B viruses and so the drugs inhibit all these viruses. Even previous pandemic viruses such as the Great Pandemic of 1918 have a near identical active site and are inhibited. Drug-resistant mutants have been described but to date appear less pathogenic and less infectious than the wild-type virus and thereby would not be expected to spread in the community. Although research is continuing with anti-common cold drugs none to date has shown strong enough clinical effects to warrant extensive use and virtually no drugs exist for the remaining important respiratory viruses, namely adenoviruses, parainfluenzaviruses or coronaviruses.

The Most Recent Past And The Future

New herpesviruses continue to be discovered, whilst only HHV1 and 2 are significantly inhibited by the existing drugs. Threats of bioterroism will lead to evaluation of drugs against smallpox such as cidofovir and against viruses which cause haemorrhagic fevers such as Lassa and Ebola. Influenza has recently been added to the list of potential bioterrorist viruses. Scientifically, major drug discoveries are most likely to emerge from a judicious mixture of biology and X-ray crystallography whereby existing compounds are closely analysed for their binding or target interactions at the molecular level. Already this approach has led to the refinement of the two drugs binding to influenza A and B neuraminidase, protease inhibitor of HIV and a drug against the common cold virus. Virologists are anticipating a new influenza pandemic and therefore antivirals with a broad antiviral spectrum would be comforting to have. Amantadine itself does inhibit most, if...

Epidemiologic Evidence That Influenza Increases the Risk of Bacterial CAP

Inter-Pandemic Influenza Pandemic Influenza Evidence supporting the relationship between influenza and bacterial CAP during previous pandemics far outweighs the evidence available from studies conducted during inter-pandemic periods 55 . Of the 3 influenza pandemics in the 20th century, 1 occurred in the pre-antibiotic era and all 3 occurred in the era before effective influenza and pneumococcal vaccines and influenza antiviral medications were available. 1918-1919 Influenza Pandemic The 1918-1919 pandemic caused more illness and death than the other two 20th century pandemics combined. Approximately 500 million persons, one third of the world's population, were infected and 50-100 million persons died 56, 57 . A key determinant of the severity of that pandemic was the influenza virus itself, the virulence of which likely led to severe lung inflammation 58, 59 . Attack rates of secondary bacterial pneumonia during the 1918 pandemic ranged from 7.1 to 20 , depending on the phase of the...

Postencephalitic Parkinsonism

Following the pandemic of encephalitis lethargica (von Economo's disease), in the early part of the 20th century, a large proportion of individuals who survived the acute encephalitic phase developed parkinsonism, after a latency of several years or decades. PEP was therefore common in the 1940s and 1950s but is now rarely encountered. Although a viral etiology (possibly influenza A) has long been suspected, this remains to be proven (164,165).

Antimicrobial Resistance After the Introduction of Antiretroviral Therapy into Developing Countries

In the case of HIV, drug-resistant strains have been recognized as a serious threat to the efficacy of current antiretroviral treatment and could jeopardize efforts to increase access to treatment in countries most affected by the HIV pandemic (Gallant 2007). The potential for the transmission of HIV drug-resistant strains has been recognized as a serious threat to the efficacy of current antiretroviral treatments (Shekelle et al. 2007). The preferred HAART combination used in these settings includes the use of two nucleoside reverse tran-scriptase inhibitors (NRTIs), stavudine or zidovudine and lamivudine, and one non-nucleoside reverse transcriptase inhibitors (NNRTI), mostly nevirapine. This regimen is widely available, affordable for most countries particularly as the availability of generic antiviral drugs increases (Gallant 2007 Weller 2007). This regimen has major drawbacks, such as liver toxicity, mitochondrial toxi-city, and other significant side effects, and concern about...

The 3 and 4R Tauopathies

As the chronic form of the episode, could appear years after the acute episode (175). Most salient clinical characteristics of PEP are onset below middle age, symptom duration lasting more than 10 yr, presence of oculogyric crisis, and obviously a history of encephalitis (176). The disease has been linked to the Spanish influenza pandemic that occurred at approximately the same time. The influenza virus responsible for the Spanish flu has been isolated from an archival 1918 autopsy lung sample its RNA was not detected in archival brain tissues from acute encephalitis lethargica. These data make the connection between Spanish flu and encephalitis lethargica doubtful (177).

Anti Influenza Drugs The Development of Sialidase Inhibitors

Abstract Viruses, particularly those that are harmful to humans, are the 'silent terrorists' of the twenty-first century. Well over four million humans die per annum as a result of viral infections alone. The scourge of influenza virus has plagued mankind throughout the ages. The fact that new viral strains emerge on a regular basis, particularly out of Asia, establishes a continual socio-economic threat to mankind. The arrival of the highly pathogenic avian influenza H5N1 heightened the threat of a potential human pandemic to the point where many countries have put in place 'preparedness plans' to defend against such an outcome. The discovery of the

Influenza The Virus and Disease 11 General

As a result of the emergence of the extremely aggressive avian H5N1 influenza virus, the likelihood of a human influenza pandemic and the possible socioeconomic impact is now of major concern. In the absence of strain-independent anti-influenza drugs, there has been significant effort worldwide over the years in the quest for the discovery of novel therapeutic agents against all types of influenza.

Dale J Hu Danuta Pieniazek Timothy D Mastro

The human immunodeSciency virus (HIV) and its most severe clinical manifestation, the acquired immunodeS-ciency syndrome (AIDS), have produced a pandemic of unprecedented proportions. By the end of the year 2001, the Joint United Nations Programme on HIV AIDS (UNAIDS) estimated that there were over 40 million persons infected and living with HIV worldwide (1). Despite the rapid ascertainment of the diseaseOs epidemiology, the discovery of the etiologic agent itself and ways to prevent its spread, and the development of diagnostic tests and antiretroviral therapies, it is clear that HIV will continue to be a global problem well into the 21st century. Nevertheless, continuing advances in molecular biology, immunology, and epidemiology have contributed greatly to the understanding of HIV. This chapter will summarize the global molecular epidemiology of HIV including an overview of its genetic diversity and related implications.

Use of Functional Genomics to Understand Influenza Host Interactions

In healthy individuals however, it is responsible for 30,000-40,000 deaths each year in the United States. In extreme cases, such as the influenza pandemic of 1918, tens of millions of people have died from the infection. To prepare for future influenza outbreaks, it is necessary to understand how the virus interacts with the host and to determine what makes certain strains of influenza highly pathogenic. Functional genomics provides a unique approach to this effort by allowing researchers to examine the effect of influenza infection on global host mRNA levels. Researchers are making

Global Molecular Epidemiology

The pandemic of HIV AIDS reflects many coexisting subepidemics in different regions and populations (14,48,49). As described in the chapter entitled Global Impact of HIV, there are many important epidemiologic, sociodemographic, behavioral, and biologic factors that contribute to the differential spread of HIV.

Fetal rhesus kidney virus Synonym for

Filoviridae A family consisting of a single genus Filovirus, containing two genera, 'Marburg-like viruses' and 'Ebola-like viruses'. Both Marburg and Ebola viruses cause severe hemorrhagic fevers in humans and other primates, with extremely high mortality (up to 90 ). Marburg virus so far appears to be a single virus type, whereas four subtypes of Ebola virus have been recognized Zaire, Sudan, Reston and Cote d'Ivoire. Except for their extreme length, the viruses have a morphology somewhat similar to that of members of the family Rhabdoviridae. They are filamentous, with U-shaped, 6-shaped or circular forms produced in cell culture. The length is highly variable and can be as great as 14000 nm but it is usually about 800-1000 nm the diameter is 80 nm. The particles are enveloped with spikes ca. 7 nm in length and 10nm apart. The virus RNA is 19.1 kb in length, negative-sense and is therefore non-infectious. There are at least seven virus proteins with mol. wt. of ca. 267 (RNA Klenk...

Outbreaks of Multidrug Resistant Shigellosis in Africa and Other Developing Countries

Shigellosis can occur in sporadic, epidemic and pandemic forms. Epidemics have been reported from Central American countries, Bangladesh, Sri Lanka, Maldives, Nepal, Bhutan, Myanmar and from the Indian subcontinent, Vel-lore, eastern India and Andaman and Nicobar islands. Plasmid profile of shigellae in Kolkata has shown a correlation between the presence of smaller plasmids and shigellae serotypes indicating epidemiological changes of the species (Sur et al. 2004). For a long time now antibiotics such as ampicillin, co-trimoxazole, chloramphenicol and tetracycline have been used for treatment of shigellosis, but their use is increasingly compromised by the emergence of resistance. For example, high prevalence of resistance to ampicillin (82 ), chloramphenicol (73 ), co-trimoxazole (88 ) and tetracycline (97 ) was detected in Shigella spp. isolated from children in Tanzania (Navia et al. 1999). Brooks et al. (2003) also found a high level of resistance to the antibiotics most commonly...

Regulation of Transcription in Eukaryotes

During interphase the genetic material in association with proteins is dispersed throughout the nucleus in the form of chromatin. At the onset of mitosis, chromatin condensation takes place and during prophase it undergoes further compression into recognizable chromosomes. The associated proteins are basic, positively charged (lysine- and arginine-containing) histones and less positively charged nonhistones including high-mobility group (HMG) proteins. Histones play a key role in chromatin structural organization and are subject to various posttranslational modifications like acetylation, phosphorylation, and ubiquitination. Histones constitute nearly half of all the chromatin protein by weight and can be divided into six types HI, H2A, H2B, H3, H4, and H5. DNA is incorporated into a 100 A nucleosomal fiber comprising of two molecules each of H2A, H2B, H3, and H4 which form the core histone octamer along with one linker histone HI or H5. The nucleosome core particle consists of 146...

Viral Entry Inhibitors

Virtual screening aided in identifying structural leads for viral entry inhibitors of SARS-CoV. Compound 27, which emerged from a 50,240 compound screen and inhibited pseudovirus entry and SARS-CoV plaque formation with EC50 values of 3 mM and 1.6 mM, respectively 37 . A two-step screening of Chinese herbal medicine-based, novel small molecules which bind avidly with the S protein was performed as well. Two virus entry inhibitors, tetra-O-galloyl-p- D-glucose (28) and luteolin (29) were identified and showed anti-SARS-CoV activities with EC50 values of 4.5 and 10.6 mM, respectively 58 . After binding with ACE2, SARS-CoV is taken up into a vesicle inside the cell. Special cellular enzymes (cathepsins) act in the acidic environment inside the vesicle, facilitating fusion of the viral membrane and the vesicle membrane, so that viral proteins and nucleic acids can enter the cell where viral replication occurs 59 . Thus, the cathepsin L inhibitor, MDL28170 (30) represents an attractive...

Miscellaneous Inhibitors

Several compounds have been identified that have shown inhibitory activity against SARS-CoV. However, no information regarding their mechanism of action or the corresponding target is known. Glycyrrhizin showed inhibitory activity for SARS-CoV replication with EC50 300mg l after virus absorption in Vero cells 60 . Some glycyrrhizin acid derivatives were found to inhibit SARS-CoV replication in vitro with EC50 values ranging from 5 to 50 mM. Unfortunately, these compounds show high cytotoxity 61 . The viral entry step was suspected to be inhibited by these derivatives. Nitric oxide (NO) has shown an inhibitory effect on some virus infections 62 . An organic NO donor, S-nitroso-N-acetylpenicillamine was shown to inhibit the replication cycle of SARS-CoV in a concentration-dependent manner, probably during the early steps of infection 63 . HIV protease inhibitor nelfinavir 64 , antihelminthic drug niclosamide 65 and antimalarial agent chloroquine 66 all showed strong inhibitory activity...

Box 76 Severe Acute Respiratory Syndrome No Known Drugs

In his 1969 book, The Andromeda Strain, Michael Crichton described an alien life form brought back to earth from a secret government satellite. Deadly disease spread through a small Arizona town, wiping out much of the population in the blink of an eye. The virus-like disease was like nothing previously seen on earth. Science fiction has a perverse way of becoming reality. From November 2002 through July 2003, much of the world lived out this techno-thriller, as an unknown virus causing deadly atypical pneumonia spread rapidly from country to country. When the outbreak subsided, 8,096 known cases of infection and 774 deaths had occurred (case-fatality rate of almost 10 ). The virus causing Severe Acute Respiratory Syndrome (SARS) had disseminated from China's Guangdong province to 37 countries around the world. The virus, a type of coronavirus, spread rapidly like pandemic influenza, moving easily from person to person. In China, streets were filled with countless thousands donning...

Regulation of membrane traffic in the early secretory pathway

By a hydrophobic region at the N-terminus of P1. P1 also acts as the methyltransferase (yellow). P2 encodes the helicase (purple) and P4 is the RdRp (red). The P123 precursor associates with P4 and generates negative-stranded RNA. Further processing produces a complex of separate P1, 2, 3, and 4 proteins that produce positive-stranded RNA. (D) Nidoviruses. The Nidovirales order comprises the Arteriviridae, Coronaviridae, and Roniviridae families. The replicase gene is composed of two open reading frames termed ORF1a and ORF1b, both of which encode complex polyproteins. Arterivirus ORF1b encodes NSPs 9-12 including the RdRp (NSP9, red), helicase (NSP10, purple). The ORF1b reading frame lacks hydrophobic domains able to target the replicase to membranes. Proteins necessary for membrane targeting (brown and blue) are encoded by ORF1a (NSP2, 3, and 5). For the CoVs, for example, MHV and SARS-CoV transmembrane domains are located in NSP3, 4, and 6, and helicase and polymerase proteins are...

Estimated Exposure Risks

Heterosexually acquired HIV infections in the UK, including those among pregnant women, and the numbers of new HIV diagnoses reflect the focus of the pandemic in sub-Saharan African countries with close links to the UK. In England, Wales and Northern Ireland, of the HIV-infected heterosexual patients receiving care in 2003 (and for whom ethnicity was reported), 70 per cent were black-African. Over two-fifths of the HIV-infected heterosexuals receiving care reside and are treated outside London most of these are black-African. Among women who were born in sub-Saharan Africa and who subsequently gave birth in the UK, an estimated one in 42 were HIV-infected in 2003. However, the transmission of HIV from mother to child in the UK has been reduced greatly since the universal offer and recommendation of HIV testing in pregnancy was introduced. Despite this, undiagnosed HIV infection and late diagnosis of longstanding HIV infection continue to be a feature of the treatment histories of...

Microbicides as a novel approach to prevent HIV infection

Sexual transmission of HIV continues to fuel the HIV AIDS pandemic with greater than 90 percent of adolescent and adult HIV infections resulting from heterosexual intercourse 1 . Worldwide, approximately half of the 42 million people living with HIV AIDS are women 1,2 . A variety of biological and socioeconomic factors contribute to the vulnerability of women to infection such as anatomic and his-tological differences between female and male genital tissues 3 as well as inconsistent condom use due to partner consent or cultural acceptance 4 . As a result, women are at risk for acquiring HIV from exposure to infectious seminal fluid during intercourse with high-risk sex partners 5,6 . In the absence of an effective prophylactic vaccine or therapy, scientific efforts over the past ten years have focused on the development of safe, effective formulations of anti-HIV agents to reduce sexual and perinatal transmission of HIV 2,7 .

Avian influenza vaccine

Traditionally, vaccination has been the principal approach to protecting individuals against influenza. Currently, no influenza A H5N1 vaccine is available although several candidate vaccines are being developed. Preliminary data suggest that either higher concentrations of antigens than used in seasonal influenza vaccines and or addition of adjuvants to these vaccines will be necessary to induce protective responses 8 . Gearing production, to rapidly make necessary quantities, of such a vaccine in the event of pandemic spread will be a great challenge to the vaccine industry. Thus, although great progress has been made in understanding the biology of avian influenza H5N1 and although the virus is not presently capable of efficient human-to-human transmission there is reason for concern as noted above. Continued surveillance in animal and human populations and infection control measures to limit its spread are critical, while we learn to better combat this virus (or some other future...

Antisense Based Antiviral Therapeutics

Warfield et al. reported profound inhibition of Ebola virus in mice and rhesus macaques using antisense MF oligonucleotides (Warfield et al. 2006). Combination of several oligonucleotides targeting mRNAs for VP24, VP35, and the RNA polymerase protected the animals, both therapeutically and prophylactically. The modified oligonucleotides protected 75 of the macaques from lethal Ebola virus infection. Similarly, MF oligonucleotides were recently found to profoundly inhibit the murine hepatitis coronavirus. Treatment protected mice against a normally lethal viral challenge, but there were some indications of toxic effects (Burrer et al. 2007).

The Nidovirus replicase is generated from two polyproteins

The Nidovirales order comprises the Arteriviridae, Coronaviridae, and Roniviridae families. The replicase gene is composed of two open reading frames termed ORF1a and ORF1b. ORF1b is generated from a frameshift in 1a, and both reading frames encode complex polyproteins processed by viral proteases (Gorbalenya et al., 2006 Ziebuhr, 2006). The arterivirus ORF1b encodes NSPs 9-12, including the RdRp (NSP9) and helicase (NSP10). The ORF1b, however, lacks hydrophobic domains able to target the replicase to membranes. Interestingly, the hydrophobic domains necessary for membrane targeting are encoded by ORF1a in NSP2, 3, and 5, suggesting that ORF1a proteins produce a scaffold to locate the viral replication-transcription complex to membranes (Fig. 1D) (Pedersen et al., 1999 van der Meer et al., 1998). A similar strategy is used by CoV, for example mouse hepatitis virus (MHV) and severe acute respiratory syndrome-CoV (SARS-CoV) (Prentice etal., 2004a,b), where transmembrane domains are...

Sites of arterivirus and CoV replication are separate from sites of envelopment and budding

Several studies have investigated the intracellular sites of replication of equine arterivirus (EAV), MHV, and SARS-CoV. Such studies are difficult because during nidovirus infection, the processes of replication and envelopment occur on different membranes, and these may merge during encapsidation. Furthermore, late during infection cells infected with MHV can form syncitia. Newly synthesized MHV viral RNA has been found in perinuclear sites colocalized with the RdRp (Shi et al., 1999), and depending on whether human or murine cells were infected, these sites colocalized with Golgi or ER membranes, respectively. Similar studies in mouse L cells report that the polymerase and newly synthesized RNA locate to late endosomes and endocytic carrier vesicles (van der Meer et al., 1999). This discrepancy is in part reconciled by later work showing that the subcellular distribution of the replicase proteins can change during the course of infection, since replicase proteins move to sites of...

Antiviral RNAiBased Strategies

RNAi against the severe acute respiratory syndrome coronavirus (SARS-coronavirus) and other coronaviruses has also been studied extensively. Both siRNAs and plasmid-derived shRNAs were effective in blocking virus replication in cell culture infections (He et al. 2003 Lu et al. 2004 Ni et al. 2005 Pyrc et al. 2006 Wang et al. 2004 Wu et al. 2005a Zhang et al. 2004). Potent siRNA inhibitors against the SARS-coronavirus spike and pol mRNAs were also tested for efficacy and safety in a rhesus macaque SARS model. The siRNAs were administered intranasally as prophylactic, concurrent with viral challenge, or early post-exposure (Li et al. 2005a). Similar to the mice studies with anti-influenza siRNAs and anti-RSV siRNAs, both prophylactic and therapeutic effects were observed. siRNA treatment caused a significant reduction in viral RNA levels, SARS-like symptoms, and lung histopathology. These combined findings suggest that low dosages of inhaled or intravenously administered siRNAs or shRNA...

Influenza and Antibiotic Resistance

Summary Influenza is a viral disease that displays rapid dissemination of antibiotic resistance. The seasonal form of influenza moves around the world each winter, causing a mild, self-limiting infection for most persons. Vaccines are generally quite effective, but some patients fail to mount an adequate immune response. For such persons, antibiotics specific to flu virus have been developed. The adamantanes block productive infection of cells, whereas the neuraminidase inhibitors interfere with virus release and cell-to-cell spread. Resistance to the adamantanes has been extensive since 2005 resistance became significant for the neuraminidase inhibitors in the 2007-08 season. Pandemic influenza, exemplified by the 1918-19 outbreak and more recently by the 2009 H1N1 swine flu, sweeps around the world in a less predictable manner. Because vaccine can be produced only after human transmission is firmly established and the circulating virus strain is identified, antiviral agents are...

The doublemembraned vesicles induced by arteriviruses and CoVs may be related to autophagosomes

SARS-CoV extend from the ER and can be labeled with antibodies specific for replicase proteins. This suggests that, in common with MHV, the vesicles are a site of replication (Snijder et al., 2006). Even though all SARS-CoV replicase proteins tested colocalize to punctate structures that accumulate near the nucleus, there are conflicting reports about their relationship with autophagosomes. In monkey Vero cells, the replicase proteins colocalize with autophagosomes identified using antibodies against LC3 (Prentice et al., 2004a). However, when autophagosomes are identified by expression of GFP-LC3, the replicase proteins do not colocalize with the GFP signal (Snijder et al., 2006). The vesicles induced by SARS-CoV are smaller at 100- to 300-nm diameter than autophagosomes (500-1000 nm) and are labeled with ER markers. This has lead Snijder and colleagues to suggest that they are virus-induced extensions to the ER, rather than bona fide autophagosomes (Pedersen et al., 1999 Snijder et...

Bacterial Pneumonia May Create Another Resistance Problem

Influenza virus is only the beginning of the pandemic resistance problem. A major cause of flu-associated death is the bacterial pneumonia that follows flu.238 Indeed, in the 1918-19 pandemic, most deaths appear to have been due to follow-up bacterial pneumonia.243, 244 Although pneumonia-producing bacteria can be controlled with existing antibacterial agents, drug delivery systems will be challenged during a flu pandemic because we now rely on just-in-time supply chains. Developed countries have stockpiles of some antibacterials, but the optimal compound varies from one pathogen to another. For example, ciprofloxacin, which is quite effective with anthrax, is not recommended for pneumonia because its use with streptococcal pneumonia so often leads to resistance.76 An alternative will be needed. p-lactams, such as penicillin, and the newer fluoroquinolones are still widely used for infection by S. pneumoniae consequently, they are likely to be administered prophylactically for...

Box 123 Virus Transfer from Protective Clothing

If a lethal influenza pandemic occurs, many persons may be caring for family members at home. Although we may not have all the equipment needed, the procedures used in hospitals should be applied as best they can to slow the spread of infection. Personal protective equipment is generally worn for only a short time. In contrast, pathogens, such as SARS coronavirus and influenza virus, remain viable for hours. Infection can be spread by air, surface-to-hand contact, and hand-to-hand contact. Consequently, how one removes contaminated masks, gowns, and latex gloves is important.

Respirovirus A genus in the family

Reston Ebola virus (EBOV) Filoviridae. In 1989 an outbreak of hemorrhagic fever occurred in a non-human primate facility in Reston, Virginia, USA involving Cynomolgus monkeys imported from the Phillipines. Ebola virus was diagnosed as the cause of the outbreak and all monkeys were destroyed. At least one case of demonstrated human infection occurred, but with no associated disease symptoms. Two further outbreaks occurred in association with monkeys imported from the same facility in the Phillipines, in Siena, Italy in 1992, and in Texas, USA in 1996. The company providing the monkeys has now ceased trading. The Reston Ebola virus is highly pathogenic for monkeys, and whilst it has been suggested that it may be less pathogenic for humans this has not been put to the test, for obvious reasons. The following strains of Reston Ebola virus are recognized Reston Ebola virus Philippines Reston Ebola virus Reston Reston Ebola virus Siena Reston Ebola virus Texas.

Resistance in tuberculosis

Tuberculosis is an enormous global health problem. The burden of the disease in DCs continues to grow largely fuelled by the HIV AIDS pandemic and poor public health infrastructure (Yun et al., 2003). The incidence of tuberculosis in Africa is estimated at 259 persons per 100,000 population per year compared to about 50 per 100,000 population per year in Europe and America (Dye et al., 1999). Resistance of Mycobacterium tuberculosis to antibiotics is a man-made amplification of spontaneous mutations in the genes of the tubercle bacilli. Treatment with a single drug due to irregular drug supply,

Resistance in Hivaids

The AIDS epidemic is one single disease that has devastated societies and communities in DCs in the recent times. It has greatly enlarged the population of immunocompromised patients and left them completely defenceless and at great risk of numerous infections. About 22 million people around the world have died from AIDS, and about 40 million more are currently infected with the HIV virus (Clark and O'Brien, 2003). About 83 of AIDS deaths and 71 of HIV infections have occurred in war-ravaged, poverty-stricken DCs in sub-Saharan Africa (Mason and Katzenstein, 2000). This pandemic is ripping apart the social and economic fabric of this part of the world. Only by giving those infected with HIV effective treatments, will people be prevented from dying of AIDS in the future.

Chemogenomics knowledge space

The chemogenomics knowledge space, integrated by Paolini et al. identified chemical tools, leads and drugs for nearly 900 human proteins. Annotated chemical libraries of chemical tools that can be derived from such databases can be applied to target validation and chemical biology 20,21 . Importantly, Paolini et al. have demonstrated that new knowledge space can be created by analyzing SAR data in its entirety by mapping the interaction network between proteins in chemical space 17 . Thus, mapping the chemogenomics knowledge space enables the development of methods for the rational design of polypharmacology drugs 22,23 . The chemogenomics knowledge space also enables the ideas proposed by Frye 24 and Fliri et al. 25-27 of comparing the homology of SARs across a wide range of molecular targets to determine the relationship between structure, selectivity, efficacy and safety. The data in the chemogenomics knowledge space are not just a repository of previous experimental observation...

Artifical Intelligence In Drug Design

Whilst there is a strong tacit dimension to the medicinal chemist's knowledge, many of the tactics and techniques used to navigate chemical space that derive from experience can be articulated and therefore potentially formalized. If we can articulate the tactics used to explore SARs efficiently then the next step is to formalize and codify such knowledge. Codifying medicinal chemistry knowledge enables the goal of evolving from computer-aided drug design (CADD) to knowledge-aided drug design (KADD).

Benefits and Impact Delivering Value Through Reducing Cost and Saving Lives

Molecular differential diagnosis is necessary for controlling an outbreak, such as avian flu or SARS. A simple mathematical model shows that if one person contracts avian flu, it will likely be transfered to three additional people in four days. After 32 days, there will be 6561 people sick with the disease, increasing the probability that the disease will spread to even more people worldwide. After 4 weeks, it is virtually unstoppable. By this model, 4 weeks is the window of opportunity for public health professionals to contain a disease. With an early and accurate differential diagnosis, infected patients can be identified, isolated, and treated. In addition, the general population can be informed and protected.

Discovery development and commercialization in the face of policies

On 25 April 1953 Francis Crick and James D. Watson published their paper Molecular structure of nucleic acids in Nature (Watson and Crick, 1953), describing the double helix structure of DNA. This signalled the launch of the modern era of molecular biology and provided the foundation of our understanding of molecular medicine, transforming much of scientific research including how we approach the discovery of new drugs. On 15 April 2003, nearly 50 years after the publication in Nature, Carl B. Feldbaum of the Biotechnology Industry Organization (BIO) announced the finished version of the human genome sequence and the completion of the Human Genome Project providing an accurate map of the 3.1 billion units of DNA. At the same time, it was reported that the genome of the newly identified SARS (Severe Acute Respiratory Syndrome) virus had been sequenced in only 6 days. The Bacillus anthracis, Ames strain used in postal terrorist attacks in the United States in 2002 was reported as...

Summary And Future Prospects

There has been a substantial increase in antibiotic resistance observed in pneumo-cocci within the last decade. This has been directly connected with the spread of particular pandemic clones of multidrug-resistant strains, and the development of local epidemic strains. There are no countries that are free of multidrug-resistant PNSP however, there are pronounced differences observed in the frequencies of PNSP even between neighboring countries. As to whether this is due to differences in antibiotic usage policies, to vaccination strategies, or to other factors is unclear. Interestingly, the development of multivalent conjugate pneumococcal vaccines may have a significant impact upon the prevalence of antibiotic resistance. Included within the polyvalent vaccines are those childhood-associated serotypes 6B, 9V, 14, and 23F that represent the burden of pandemic multi-resistant clones. Eradication of these serotypes from the vaccinated population will hopefully reduce the frequency of...

Replication Of Negativesense Rna Viruses With A Monopartite Genome

Human diseases caused by the viruses of this order include relatively mild flu-like respiratory disease (parainfluenza) caused by a paramyxovirus. More severe diseases include mumps, measles, hemorrhagic fevers with high mortality rates caused by Marburg and Ebola virus (filoviruses), and neurological diseases ranging from relatively mild ones caused by bornavirus to the invariably fatal encephalitis caused by rabies virus (a rhabdovirus). The diseases characterized by high mortality rates are not maintained in human reservoirs but rather are zoonoses diseases of other vertebrates transmissible to humans (see Chapter 3, Part I).

Biochemistry of HIV1 Protease and Development of Inhibitors

4.3 The SARS Coronavirus Protease A new coronavirus was quickly identified after the outbreak of an atypical pneumonia in southern China early in 2003. The new virus eventually caused 8,000 infections with approximately 800 deaths in 29 countries. The condition was named Severe Acute Respiratory Syndrome, SARS, and the causative coronavirus named SARS-CoV. The zoonotic nature of the infection came with the identification of a similar virus in bats (Poon et al. 2005), although it is possible that the bat virus passed through other animal hosts and recombined with other SARS-like coron-aviruses prior to infecting humans (Hon et al. 2008). SARS-CoV is not currently circulating in the human population however, the mysterious appearance and rapid spread of this virus emphasized how vulnerable the human population is to such respiratory infections. This has spurred interest in the development of antivirals that could be used either in treatment or as prophylaxis to complement public health...

Human endogenous retroviruses HERV

Human enterovirus 70 (HEV70) A serotype of Human enterovirus D in the genus Enterovirus. Isolated in 1971 from epidemics of acute hemorrhagic conjunctivitis in Japan, Singapore and Morocco. These outbreaks were part of a pandemic involving millions of humans in Africa, South-East Asia, Japan, India and England during 1969-71. The virus can adsorb in vitro to cells from a wider range of species than most enteroviruses. In some it produces no CPE but in others, such as RK 13 (rabbit cells) and BK 1 (bovine cells), it produces virus and CPE. Prototype strain is AHC(J670 71). human microvascular endothelial cell line (HMEC-1) A cell line that has proved useful for propagation of filoviruses, such as Marburg and Ebola virus.

Epidemiology Of S Pneumoniae

Numerous multidrug-resistant pneumococcal clones have been identified 8 , with at least five of these shown to be major pandemic clones (http The oldest and most prevalent is pandemic or Spain23F-1. This clone has been reported in 42 countries (Figure 10.1) across all continents. Isolates of this clone are usually resistant to a wide range of anti-pneumococcal drugs, including tetracyclines, co-trimoxazole, chloramphenicol, and often macrolides. MICs for penicillin are generally 1 to 2 mg L 108 , but may reach 8 mg L 109,110 . Originally of serotype 23F this clone has acquired at least eight distinct capsular type variants 3 111 , 6B 109 , 9V 108,111 , 7 112 , 11 (http, 14 109,111,113-115 , 19A (http, and 19F 102 , with 19F being the most prevalent variant reported 71,108,111,113-118 . The early spread of the Spain23F-1 clone from Spain to the United Kingdom (Figure 10.1) was highly correlated to holidaymakers returning...

Subacute myeloopticoneuropathy virus

Sudan Ebola virus (SEBOV) A species in the genus 'Ebola-like viruses', which caused a major outbreak of Ebola hemor-rhagic fever in Sudan in 1976. See Ebola virus. Sudan Ebola virus Boniface An isolate of Sudan Ebola virus from a patient named Boniface. Sudan Ebola virus Maleo An isolate of Sudan Ebola virus from a patient named Maleo.

Genetic Diversity Of

Hiv Genetic Diversity

Based on viral genetic sequences, HIV-1 isolates have been classi&ed into a number of subtypes (alternatively termed clades or genotypes) (Fig. 3.1). These subtypes, designated by letters A, B, C, D, F, G, H, J, and K, constitute the major group of HIV-1 or group M (13,14). Phylogenetic analyses of viral sequences from numerous HIV-1 isolates worldwide have revealed two additional groups of viruses, namely groups O (outlier) and N (non-M, non-O) (Fig. 3.1). The vast majority of HIV-1 strains identi&ed worldwide, which is responsible for the global pandemic, belong to group M. Besides the various subtypes within group M, more detailed analyses have revealed additional complexities in the classi&cation of strains (15). For example, some subtypes are further subdivided into sub-subtypes (16). Other strains can only be classi&ed within a group but fail to cluster with known subtypes (17).

Degeneration And Aggregation Of Vzv

Measles virus, and JC polyomavirus) (Figure 51-15). In addition, the etiology of newly recognized viral syndromes can be recognized rapidly by identifying characteristic viral morphology by EM in infected tissue. This was exemplified by the early recognition of Ebola virus as the cause of an outbreak of viral hemorrhagic fever in Africa in the 1970s and sin nombre virus as the cause of fatal pneumonia in the four corners area of the United States in the 1990s.

Laboratory Diagnosis Of Viral Infection

Antiviral drugs, the commerdal availability of reagents, and development of rapid diagnostic techniques by conventional methods such as fluorescence microscopy and enzyme immunoassays, the ready availability of cell lines for cell culture procedures, and the introduction of real-time PCR for the detection of viral genomes. Additionally, improved medical care, in the forms of organ transplantation and immune suppression accompanying cancer therapy, have expanded gready the number of patients acquiring viral disease. Combining these with the appearance of new viral diseases threatening local and world populations (e.g., SARS, avian influenza, monkeypox), makes the laboratory diagnosis of viral infection more important and achievable than in previous years. In deriding which virology tests to offer, those in each clinical laboratory should determine whether the test is required for the appropriate care of their patient population and whether techniques are available that provide an...

Filoviruses and their pathogenesis

In 1976 an outbreak of a similar disease with a significantly higher mortality rate (50-90 ) occurred in Zaire and Sudan. Eventually, over 500 individuals were infected. A virus related to Marburg virus, named Ebola virus, was proved to be the infectious agent by identification of specific antibodies in the blood of victims and survivors. Several sporadic outbreaks of this disease have been reported in Africa since then. Most recently (2005) outbreaks have been reported in the Republic of the Congo, in Etoumbi and Mbomo. The high mortality rate of Ebola virus infection and its proclivity for spread to hospital workers via contaminated blood, respiratory aerosols, and body fluid contamination have made it a favorite subject for doomsayers and sensationalists in the media. Hollywood entered the scene with the recent movie Outbreak, which was generally inaccurate and misleading. Still, the properties of the disease and its ease of spread have served as a warning to public health workers...

Novel Antiviral Strategies

An important fraction of novel approaches involves the targeted silencing of viral gene expression through either specific degradation of a viral messenger RNA or by blocking its translation into protein. Antisense RNAs or ribozymes have been suggested and evaluated as implements for this purpose. More recently, gene silencing mediated by small interfering RNA (siRNA) has emerged as a powerful tool for molecular and cell biology. Although originally described in plants, RNA interference has also been detected in animals, including mammals, and findings in plants, Caenorhabditis elegans, and Drosophila indicate that it may have originated as an ancient intrinsic defense mechanism against viruses (Waterhouse et al. 2001 Wilkins et al. 2005 Galiana-Arnoux et al. 2006 Wang et al. 2006). Since methods for gene silencing by siRNA in experimental settings have been established and interfering RNAs can be designed against any gene with known sequence, the silencing of virus-specific genes by...

Acute infections followed by virus clearing Colds and respiratory infections

The epidemiology of influenza is an excellent model for the study of virus spread within a population. While symptoms can be severe, in part due to host factors, the virus infection is localized, and the virus is efficiently cleared from the host. Flu viruses have evolved unique mechanisms to ensure constant generation of genetic variants, and the constant appearance of new influenza virus serotypes leads to periodic epidemics of the disease. Some of these mechanisms are described in detail in Chapter 15, Part IV. The respiratory distress caused by most strains of flu virus is not particularly life threatening for healthy individuals, but poses a serious problem for older people and individuals with immune system or respiratory deficiencies. Some strains of the virus cause more severe symptoms with accompanying complications than others. At least one strain, the Spanish strain of 1918 (H1N1), caused a worldwide epidemic with extremely high mortality rates in the years immediately...

Cholera in the Time of Resistance

Cholera is a deadly dehydrating diarrheal disease caused by cholera toxin-producing Vibrio cholerae strains. Although referred to as 'Asiatic' cholera because an endemic focus exists in the Indian sub-continent, cholera has caused at least seven pandemics in recent history and the most recent focus of the on-going pandemic is Africa where over two-thirds of outbreaks in the last decade have occurred (Griffith et al. 2006). This present pandemic has been characterized by appearance of new V. cholerae lineages, including strains belonging to serotypes other than O1 and, critically, antimicrobial-resistant isolates.

Haemorrhagic Fever Viruses

Marburg Ebola disease These viruses are enveloped negative-sense single-stranded RNA viruses forming filamentous elements of varying lengths up to 1400 nm. They cause the severe haemorrhagic fevers termed Marburg (from an outbreak associated with monkeys imported to Europe) and Ebola (a river in the Democratic Republic of Congo, formerly Zaire) diseases. The transmission cycles of these viruses are elusive, but person-to-person transmission seems to be important in human outbreaks. Serological surveys from Central Africa indicate that filoviruses commonly cause subclinical infections in these areas. The natural host is unknown.

Emergence of Antibiotic Resistant V cholerae Outbreaks

Outside the human body and can spread rapidly where living conditions are crowded and water sources unprotected and where there is no safe disposal of faeces (WHO 2000). These conditions are common in poor countries and in crowded settings such as refugee camps. For example, in 1994 in a refugee camp in Goma, Democratic Republic of the Congo, a major epidemic took place. An estimated 58,000-80,000 cases and 23,800 deaths occurred within 1 month (Goma Epidemiology Group 1995). Cholera is now considered a reemerging disease because infections are appearing in novel communities or communities where the disease had been absent for many years, and the range of areas of endemicity is expanding. To date, nearly 200 serogroups of V. cholerae have been recorded, of which only the O1 and O139 strains have been associated with major epidemics due to their ability to express the cholera toxin (CT) which is rarely found in non-O1 and non-0139 serogroups (Anderson et al. 2004). In chronological...


Of the many reported analogs, only compounds 5 (GSK-3, IC50 2nM CDK1 cyclinB, IC50 19 nM and CDK5 p25, IC50 6nM) and 6 (GSK-3, IC50 7nM CDK1 cyclinB, IC50 50 nM and CDK5 p25, IC50 18 nM) displayed single-digit nanomolar activity, and none of the analogs were particularly selective for GSK-3. Interestingly however, there appeared to be interdependent SARs at the positions explored, with the optimal group at one vector being dependent on the functionality incorporated at the other positions explored. This would argue that a matrix-based optimization of this chemotype could lead to further enhancements in potency and selectivity.

Isbn 9783805593236

51 Antibiotic Resistance and Community-Acquired Pneumonia during an Influenza Pandemic The authors of these chapters have focused on issues in various aspects of antimicrobial resistance that challenge our ability to slow its inexorable progress, and how we can make the best use of the effectiveness of currently available antimicrobials. Miller examines the changing epidemiology of methicillin-resistant S. aureus that is creating diagnostic challenges and forcing the creation of new prevention strategies. Paterson and Doi describe the detection dilemmas and dwindling choices of antimicrobial drugs for critically ill patients infected with these organisms. Parry details the explosive increase in the use of fluoroquinolones for a wide range of diseases and the equally wide ranging resistance consequences, including food-borne pathogens and sexually transmitted infections. Moore and Whitney provide timely analysis of the role of secondary bacterial pneumonia in the context of an...

Patricia L Fleming

Understanding the epidemiology of HIV provides an important foundation for clinicians in recognizing risk behaviors associated with clinical manifestations suggestive of HIV infection in their patients, and encouraging acceptance of HIV testing, adoption of risk-reduction strategies to prevent further transmission, and treatment to prevent opportunistic illnesses and delay disease progression. At the start of the third decade of the HIV pandemic, and following the terrorism of September 11, 2001 and the subsequent bio-terrorism, the government and the public have a heightened awareness of the crucial role of public health preparedness in assuring well-being.


It is not impossible that in the future we might experience a global pandemic of some multiply resistant pathogen that seeks to rival the postulated impact of avian influenza. Indeed the impact of any strain of pandemic influenza would be significantly accentuated by MRSA. Events such as this would put antimicrobial resistance firmly on the political agenda and help prioritize the research required for finding another way of treating infection.

The Target Viruses

Two new anti- by mutation and selection, evade the blocking effects of a single inhibitor. Therefore, as with tuberculosis, the practical answer is to find inhibitors of a wide range of virus-specific enzymes or proteins and to use them in a patient simultaneously. This search for new drugs will be a continuing need as it is with antibacterials. Similarly, inhibitors of pandemic and epidemic influenza A viruses will need the continuing attention of antiviral chemotherapists. The human herpes viruses (HHV1-8) cause a remarkably diverse range of important diseases and will continue to remain important targets, especially VZV (varicella-zoster virus or shingles), which will reach new importance in a world population with increasing longevity. Common cold viruses and other viruses of the respiratory tract cause pathogenesis in the upper respiratory tract during all months of the year in all countries of the world and hence have economic importance. The eight or...

General Discussions

Regional differences and the potential of unknown infective agents must be included in any discussions of the future prospect of blood substitutes. Also to be included is the degree of regulatory requirements. Blood substitutes are urgently needed in regions of the world where there are severe shortages of donor blood because of cultural or religious beliefs that cause people to be less willing to donate blood. They are also urgently needed in regions with higher incidences of infective agents like HIV and thus a higher potential for contaminated donor blood. It is less urgent in regions with a lower incidence of HIV and where costly screening tests are being used to screen out infective agents in donated blood. On the other hand, it is important to remember the past unexpected outbreaks of HIV and hepatitis C and the resulting contaminated donated blood that persisted for years until proper screening tests are developed. If this should happen again with some yet unknown agents, (e.g....

Emerging Issues

The third decade of the HIV pandemic looms ahead with innumerable challenges. Advances in prevention science and a growing number of treatment regimens have raised new research, surveillance and programmatic issues (117,118). Behavioral risk reduction has been achieved in many at-risk populations, notably safer sex and injecting practices among MSM and IDUOs, respectively, but as people with HIV are diagnosed earlier and survive longer on treatment, sustaining safer sex and drug-using behaviors among infected persons will require ongoing programs to reduce further transmission. Reports of ongoing risky sexual behaviors among infected persons emphasize the need for research studies to identify effective interventions, programs to support risk reduction, and monitoring of behavioral risk factors (119). Behavioral surveillance efforts in at-risk and infected populations have lagged disease surveillance efforts. Rapid clinical advances have been accompanied by reports


The next phase in a lead discovery project is the hit-to-lead (H2L) process 52 . This is characterized by less filtering and a broader knowledge of the hits for a subsequent prioritization 17 . During the H2L process, data regarding toxicity, bioactivity, and intellectual property are assembled (Figure 1.3). One of the first actions in the H2L process is usually to purchase or synthesize structurally related compounds which are then tested together with the confirmed hits for their target activity and, by screening in bioassays against intact parasites in culture, for their anti-parasitic activity. In this way, data related to the on-target activity and initial structure-activity relationships (SARs) of the compound classes are generated. The experiments also provide the first hints regarding the bioactivity of the compound classes. If the compounds are inactive in the bioassays, then data arising from solubility, lipophilicity, or permeability experiments may explain the lack of...


Acquired immunodeficiency syndrome (AIDS) is a fatal disease that was first reported in the United States in 1981 and has since become a major worldwide epidemic. By the end of 1999, more than 600,000 Americans had been diagnosed with AIDS, which began its spread among male homosexuals but is now more prevalent among minority populations.


For centuries, influenza virus has plagued humankind. While influenza infection typically causes mild-to-moderate illness in healthy individuals, it still results in 30,000-40,000 deaths per year in the United States. Those most susceptible to influenza infection are infants, the elderly, and those individuals that are immunocompromised due to HIV AIDS infection or organ tissue transplant (CDC, 2006). In extreme cases, such as the 1918 pandemic, it is estimated that 50 million people died as a result of influenza infection (Taubenberger and Morens, 2006). What was unique about this pandemic is that the most susceptible to this disease were young, otherwise healthy, individuals. Since 1918, multiple influenza pandemics have occurred, although none nearly as deadly. Another influenza pandemic is inevitable and much effort is being placed on disease surveillance and monitoring of transmission across species (Pandemic Flu, 2007 Subbarao and Joseph, 2007). Of particular concern is the H5N1...

Murine models

Of all the influenza viruses that have surfaced in the last century, very few have caused as much intrigue as the 1918 pandemic strain. Among the most perplexing questions surrounding the influenza pandemic of 1918 is what made this virus so deadly. Environmental, biological, or demographic factors could have contributed to its virulence however, the most pertinent factors may be related to how this virus interacts with the host innate immune response. As mentioned in the previous section, we used functional genomics to study the effect of the 1918 NSi on global gene expression using a cell culture system. While this study provided an important first step in understanding this deadly virus, it only hints at what might be occurring in the whole host.


From the functional genomics experiments published so far, we have been able to gain invaluable insight into influenza pathogenesis. Perhaps the most critical use of this technology has been in the study of the virus responsible for the deadly 1918 influenza pandemic. In regards to highly pathogenic influenza, future experiments should also focus on the effect of avian H5N1 infection on global gene expression, using multiple model systems such as those that are being used to study the 1918 virus.

PLpro Inhibitors

Numerous studies on the structural and mechanistic aspects of SARS-CoV 3CLpro have provided multiple avenues for structure-based design of antiviral compounds targeted against the 3CLpro active site 9,16,44,45 . On the other hand, structure-based design against the membrane-associated PLpro enzyme, either from SARS-CoV or related coronaviruses, has remained elusive due to lack of structural information. Unlike many coronaviruses that encode two PLpro paralogs (PLP1 or PLP2), SARS-CoV has a single copy of PLpro that cleaves pp1a at three sites at the N terminus to release nsp1, nsp2 and nsp3, respectively 10,46 . Interestingly, these cleavage sites bear strong resemblance to the C-terminal tail of ubiquitin (consensus sequence LXGG). As a result, it was hypothesized that SARS-CoV PLpro may have de-ubiquitinating activity 47 . Recently, the catalytic domain of PLpro was purified and it was shown that it efficiently disassembles di- and branched polyubiquitin chains, cleaves...

Future Prospects

The development of sialidase-based inhibitors as anti-influenza drugs has provided a first line-of-defence to safeguard humanity against a potential pandemic and most importantly to buy time for vaccine and further anti-influenza drug development. Most exciting is that new opportunities exist for next generation sialidase inhibitor development.

Future Outlook

It is with unprecedented rapidity that a basic understanding of SARS-CoV life cycle has been achieved. Already, a number of targets including SARS-CoV 3CLpro and SARS-CoV PLpro appear very promising for anti-SARS-CoV chemotherapy. Since the global outbreak of SARS ended in 2003, only a small number of cases of SARS associated with laboratory exposures have been reported. However, with the identification of Chinese horseshoe bats as an animal reservoir for SARS-CoV, the potential danger of the transfer of this virus to humans still exists. To date, there is no effective therapy for the treatment of SARS in humans. While structure-based design and the screening of compounds have provided a number of promising structural leads for SARS-CoV 3CLpro, potent, low molecular weight inhibitors with less toxicity are needed for development. Interest in structure-based design and screening of SARS-CoV PLpro will increase since the X-ray structure of SARS-CoV PLpro was recently determined....

Airborne Viruses

Many respiratory viruses move from person to person through small droplets created by coughing, sneezing, and talking.164 We can also pick up viruses on our hands. When we touch our faces, the viruses then pass to nose and mouth. Shaking hands passes the virus. Many of the precautions mentioned for stopping M. tuberculosis transmission are useful with viruses masks, gowns, gloves, and controlled airflow. Among the more notorious airborne viruses are the cold viruses, influenza virus, and severe acute respiratory syndrome (SARS). Influenza and SARS are major killers that merit additional discussion. Antibiotics are available for influenza, which we discuss in Chapter 11, Influenza and Antibiotic Resistance. SARS is inherently drug-resistant, that is, we have no antibiotic for it. This disease broke out in China in 2002, and the virus quickly spread to Hong Kong. From there, it moved to Toronto where hospital workers carried the disease to the community (see Box 7-6). Stringent...


Lysis of the hepatocyte then releases the merozoite form of P. falciparum, which invades host red blood cells (RBC's), feeding on hemoglobin during the erythrocytic portion of its life cycle (7). In the RBC, the parasite expresses a number of polypeptide products that are exported to the surface of the RBC, rendering it antigenic. These peptides are products of the var, rif, and dag genes located on chromosome 2 and 3 of the P. falciparum genome, and allow the infected RBC's to adhere to vessel walls, and to accumulate in specific organs such as the brain (2,3). In order to escape the host immune system, the parasite regularly exchanges these peptides in a process called antigenic variation. Although P. falciparum has a complex biochemistry and life cycle, recent research has revealed a number of potential new drug targets (6). Malaria has become more difficult to treat, due to an increase in multi-drug resistant strains (8). Indeed, the reemergence of malaria...

Helicase Inhibitors

Since the pioneering work of Kleymann et al. (2002), Betz et al. (2002), Baumeister et al. (2007), and Crute et al. (2002), who showed that compounds identified as inhibitors of the helicase-primase enzyme complex could alleviate herpesvirus-induced disease in animal models, the attention of researchers developing antiviral compounds has been drawn more and more towards the virus-encoded helicases, particularly those of Herpes viruses and of RNA viruses such as Hepatitis C Virus (HCV) and SARS coronavirus (SARS-CoV). Enzyme activity is usually assayed by measuring NTPase activity in the presence of an appropriate nucleic acid co-substrate although, more recently, novel fluorimetric and luminescence principles have been applied to the measurement of strand unwinding and or translocation of the protein along the nucleic acid (Frick 2003, 2006). Helicase has also been a focal point for the development of antiviral chemotherapy of the coronavirus associated with severe acute respiratory...

Avian Influenza

The influenza virus genome is composed of 8 segmented pieces of RNA with each coding for a separate viral protein. These viral proteins may change slowly (antigenic drift) through point mutations occurring during viral replication or suddenly (an-tigenic shift). The latter occurs only in influenza A strains and it results from a combination of the segmented genome described above and the ability of influenza A strains of human and avian origin to co-infect the same host (typically, pigs or swines are most receptive), and share their genetic information. During this process of re-assortment a new strain acquiring one of the avian surface protein genes (H or N) may emerge. Such a novel strain then eludes pre-existing immunity in people previously infected with influenza and may spread rapidly among the entire population. This defines the potential for worldwide spread or an influenza pandemic. A number of influenza pandemics were documented over the 20th century with the most notable...


Recently, coronaviruses have been recognized as causes of severe lower respiratory tract infections. The SARS coronavirus caused severe CAP associated with high mortality rates, even in previously healthy adults.27, 28 Non-SARS coronaviruses such as the coronavirus OC43 have been associated with lower respiratory tract infections in children and adults.25, 29-31 Human metapneu-movirus is increasingly recognized as a cause of respiratory failure in children and of pneumonia in the elderly.32, 33 Importantly, up to 60 of episodes of CAP remain of unknown etiology.6

Technical Aspects

Of the vector genome resulting in concatamerization of a starting monomer has been the rule in several studies in which small expression cassettes were rescued as deleted adenoviral vectors. The vector preparations consisted of viral particles that contained both monomeric and dimeric genomes and frequently were mixtures of particles with head-to-head, head-to-tail, or tail-to-tail DNA concatemers 6, 14, 28, 29 . This size-dependence of stable vector production was confirmed with the loxP production system that was used to rescue and propagate HC-Ad vectors with differently sized vector genomes as starting material. Only vectors with genome sizes of at least 27 kb allowed efficient and stable vector amplification 30 . Thus, stuffer DNA has to be added to the therapeutic gene cassette to bring the total vector genome size to at least 27 kb. Some practical considerations are outlined here. Since approximately 30-kb plasmids are typically used for vector construction, the stuffer DNA...


Coronavirus is an RNA virus known to be associated with respiratory disease. Severe acute respiratory syndrome (SARS) virus is a newly recognized coro-navirus whose genome sequence does not belong to any of the known coron-avirus groups and which quickly spread all over the world from Asia in 2003. There has been no evidence that this infection is transmitted from blood donors to transfusion recipients, but the virus associated with SARS is present in the blood of people who are sick, and it is possible that the virus could be present in blood immediately before a person gets sick, so that an individual with infection but no symptoms possibly could transmit SARS through a blood donation. To help determine whether or not an individual might be infected with SARS, a blood collection facility will ask a potential donor orally or in writing about any travel to a SARS-affected country or a history of SARS or possible exposure to SARS. Enzyme-linked immunoassays for detection of specific...


The Southern Research Molecular Libraries Screening Center (SRMLSC) is based at Southern Research Institute (SRI), where more than 20 anti-cancer agents have been discovered and entered into clinical trials, six of which received FDA approval and proceeded to market. The SRMLSC brings extensive drug discovery and development expertise to the network, especially in the areas of cancer, neurological diseases CNS disorders, and infectious disease (HIV, hepatitis, TB, and emerging pathogens including influenza, H5N1 Avian flu, West Nile virus, and SARS coronavirus). The screening center has broad capabilities to implement any cellular, molecular, or target-based assay including those which require BSL-3 containment, and optimizes or miniaturized them as necessary. The HTS facility is equipped with state-of-the-art instrumentation to screen in up to 1536-well plate format, including two ORCA robotic rails, multiple plate readers, and two Biomek FX liquid handlers, a BioRaptr, and an Echo...

Possession Of Facts

Interestingly, in both categories, the number of available relevant facts, both known a priori and generated in situ during the course of drug discovery project, can be very large, and yet chemists never quite have complete information to make their choices with certainty. During the course of a drug discovery project the laboratory measurements for a series of compounds reveal the structure-activity relationships (SARs) and the structure-property relationships (SPRs). These relationships then provide a priori information for the next generation of drug discovery projects to learn from. New knowledge is created within a project by exploration of the SARs and the testing of the compound through the hierarchy of biological and toxicity assay through to the clinic. However, the previous experience of medicinal chemistry also provides a rich source of information from which to derive new knowledge, useful to selecting and guiding drug-design programs. Prior knowledge provides an ontology...


Severe acute respiratory syndrome (SARS) is a new infectious disease that first emerged in Guangdong province, China, in November 2002. SARS is caused by a novel coronavirus (SARS coronavirus) of animal origin. Within months, more than 8000 patients worldwide (with approximately 700 deaths) were affected. The virus has not been detected in humans in subsequent years, but the animal reservoir and live animal markets in China are still present, allowing animal-to-human transfer to once again happen. Low levels of Virus Ebola (aka Ebola-Reston) and Marburg viruses Filoviruses (Table 51-9) are the most pathogenic of the hemorrhagic fever viruses. The name filo means threadlike, referring to their long filamentous morphology as seen with electron microscopy. Infections with Marburg or Ebola viruses, endemic in Africa, result in severe hemorrhages, vomiting, abdominal pain, myalgia, pharyngitis, conjunctivitis, and proteinuria. Case-fatality rates of 90 are expected with Ebola virus...


1,4-Dihydropyridines (DHPs) are widely used as antihypertensive agents due to their ability to block the L-type calcium channel. DHPs have also been characterized as potentiators of several mutant CFTR channels 51 . The potentiator activity of this class of compounds appears to be mediated by CFTR and not by inhibition of calcium channels. In FRT cells expressing the F508del mutation, felodipine (8) showed a 30-fold potency improvement over genistein (Ka 23.6 jmM) with a measured Ka of 0.7 j M. Compound 8 was extensively characterized and was shown to be an effective potentiator of wild-type CFTR (Ka 0.5 jmM genistein, Ka 16 jmM) and of the G551D mutation, albeit at higher concentration than those required to potentiate F508del-CFTR (Ka 23.3 j M). Patch-clamp data for 8 using inside-out configuration experiments in FRT cells expressing the G551D were recorded. The data indicated that the addition of 100 jmM of 8 resulted in 10-fold increase in the open probability of the channel....


A series of descladinosyl-6-O-methylerythromycin A-11,12-carbamate-3-O-esters showed good in vivo activity in a mouse lung S. pneumoniae infection. FMA 1082 19 was comparable to telithromycin 11 in this model and gave high levels in lung tissue following an oral dose 46 . Derivatives of tylosin have been prepared in which each of the neutral sugars have been replaced. From the monoglycoside, OMT 20, replacement of the original 4'-sugar with arylalkyl groups overcame erm and mef resistance in S. pneumoniae and somewhat less efficiently in S. pyogenes 47 . Acylation (carbamates) or alkylation at the 23 position was less effective at overcoming resistance but did maintain good activity against H. influenzae 48 . An extensive effort to extend many of the beneficial SARs from ketolides to azalides has not been met with major success 49 .