Bacterial pneumonia in HIV-infected patients.

Individuals infected with the human immunodeficiency virus (HIV) are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. Streptococcus pneumoniae and Haemophilus influenzae are the most common causes of bacterial pneumonia in HIV-infected patients. However, more unusual bacteria can also cause pneumonia. Response to therapy is generally good for infections caused by pyogenic organisms, and complications are relatively few. Unfortunately, infections caused by Rhodococcus equi and Nocardia species are associated with significant morbidity and mortality. Moreover, the duration of therapy is long, and relapes are common. Prevention of bacterial pneumonia is an important part of the care of HIV-infected patients; the 23 valent pneumococcal vaccine is currently recommended for all HIV-infected patients. The role of other preventative measures remains unknown.