Routes of Transmission

Although genital tract infections can be caused by members of the patient's genital flora (endogenous infections), the overwhelming majority of lower genital tract infections is sexually transmitted.

Sexually Transmitted. Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, human immunodeficiency virus (HIV), Treponema pallidum, Ureaplasma urealyticum, Mycoplasma hominis, other mycoplasmas, herpes simplex virus (HSV), and others may be acquired as people engage in sexual activity. In addition, other agents that cause genital tract disease and may be sexually transmitted include adenovirus, coxsackievirus, molluscum contagiosum virus (a member of the poxvirus group), the human papillomaviruses (HFVs) of genital warts (condylomata acuminata; types 6, 11, and others) and those associated with cervical carcinoma (predominandy types 16 and 18, but numerous others are also implicated), Calymmatobacterium granulomatis, and ectoparasites such as scabies and lice. Some of these

Table 58-1 Major Causes of Genital Tract Infections and Sexually Transmitted Diseases

Frequency

Disease

Agent

Organism Group

More common

Genital and anal warts (condyloma);

cervical dysplasia; cancer Vaginitis

Urethritis/cervicitis (also acute salpingitis, acute perihepatitis, urethritis, pharyngitis) Herpes genitalis (genital/skin ulcers) AIDS

Hepatitis (acute and chronic infection)

Human papillomavirus

Gartinerella/Mobiluncus, Trichomonas vaginalis, Candida albicans Nässeria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum Heipes simples virus type 2 (less commonly type 1) Human Immunodeficiency virus (HIV) Hepatitis B virus

Viruses

Bacteria, parasites, fungi

Bacteria

Viruses

Viruses Viruses

Less common

Lymphogranuloma venereum

Granuloma Inguinale

Syphilis

Chancroid

Scabies, mites

Pediculosis pubis, "crabs* infestation Enteritis (homosexuals/proctitls)

Molluscum contagiosum Heterophile-negative mononucleosis, congenital infections

Calymmatobacterium granulomas (Donovania)

Treponema pallidum

Haemophilus ducreyi

Sarcoptesscabel

Phthirius pubis

Giardia lamblia, Entamoeba histolytica, Shigella spp., Salmonellaspp. Enterobius vermicularis, Campylobacters^., Helicobacters^. Poxlike trims Cytomegalovirus

Bacteria

Bacteria

Bacteria

Bacteria

Ectoparasites

Ectoparasites

Bacteria, parasites

Viruses Viruses

agents are not routinely isolated from clinical specimens. Infections with more than one agent may occur and therefore dual or concurrent infections should always be considered.

An individual's sexual habits and practices dictate potential sites of infection. Homosexual practices and increasingly common heterosexual practices of anal-geriital or oral-genital intercourse allow for transmission of a genital tract infection to other body sites such as the pharynx or anorectal region. In addition, these practices have required that other gastrointestinal and systemic pathogens also be considered etiologic agents of STDs. The intestinal protozoa Giardia lamblia, Entamoeba histolytica, and Cryptosporidium spp. are significant causes of STDs, especially among homosexual populations. In the same group of patients, fecal pathogens, such as Salmonella, Shigella, Campylobacter, and Microsporidium, are often transmitted sexually. Oral-genital practices probably allow N. meningitidis to colonize and infect the genital tract. Viruses shed in secretions or present in blood (cytomegalovirus [CMV]; hepatitis B, possibly C and E; other non-A, non-B hepatitis viruses; human T-cell lymphotropic virus type I [HTLV-I]; and HIV) are spread by sexual practices.

Certain infections that are sexually transmitted occur on the surface epithelium of or near the lower genital tract. The major pathogens of these types of' infections include HSV, Haemophilus ducreyi, and T. pallidum.

Other Routes. Organisms may also be introduced into the genital tract by instrumentation, presence of a foreign body, or irritation and can subsequently cause infection. Infections transmitted in this way are often caused by the same organisms that cause skin/wound infections. Of great significance, infection can also be transmitted from mother to infant either in vivo (within the living body) or during delivery. For example, transplacental infection may occur with syphilis, HIV, CMV, or HSV. Infection in the newborn can also be acquired during delivery by direct contact with an infectious lesion or discharge in the mother and a susceptible area in the infant (e.g., the eye). STDs, such as HSV, C. trachomatis, and N. gonorrhoeae, may be transmitted from mother to newborn in this manner. Other organisms, such as group B streptococci, Escherichia coli, and Listeria monocytogenes, that originate from the mother may also be transmitted to the infant before, during, or afterbirth. (Infections in the fetus and newborn are discussed later in this chapter.)

Bacterial Vaginosis Facts

Bacterial Vaginosis Facts

This fact sheet is designed to provide you with information on Bacterial Vaginosis. Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina.

Get My Free Ebook


Post a comment