Otitis Media Middle Ear Infections

In children (in whom otitis media is most common), pneumococci (33% of cases) and Haemophilus influenzae (20%) are the usual etiologic agents in acute disease. Group A streptococci (Streptococcus pyogenes) are the third most frequendy encountered agents, found in 8% of cases. Other organisms, encountered in 1% to 6% of cases, include Moraxella catarrhalis, Staphylococcus aureus, gram-negative enteric bacilli, and anaerobes; in one recent study, M. catarrhalis, S. pneumoniae, and H. influenzae were the most common bacterial pathogens.9 Viruses, chiefly respiratory syncytial virus (RSV) and influenza virus, have been recovered from the middle ear fluid of 4% of children with acute or chronic otitis media. Chlamydia trachomatis and Mycoplasma pneumoniae have occasionally been isolated from middle ear aspirates. Otitis media with effusion (fluid) is considered a chronic sequela of acute otitis media. A slowly growing organism, Alloiococcus otitidis is a potential pathogen that is found solely in patients with otitis media with effusion.1,5

Chronic otitis media yields a predominantly anaerobic flora, with Peptostreptococcus spp., Bacteroides fragiHs group, Prevotella melaninogenica (pigmented, anaerobic, gram-negative rods), and Porphyromonas, other Prevotella spp., and Fusobacterium nucleatum as the principal pathogens; less frequendy present are S. aureus, Pseudomonas aeruginosa, Proteus spp., and other gram-negative facultative bacilli. Table 56-2 summarizes the major causes of ear infections.

The mastoid is a portion of the temporal bone (lower sides of the skull) that contains the mastoid sinuses (cavities). Mastoiditis is a complication of chronic otitis media in which organisms find their way into the mastoid sinuses.

Table 56-2 Major Infectious Causes of Ear Disease

Disease | Common Causes

Otitis externa

Acute: Staphylococcus aureus, Streptococcus

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.

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