Clinical and microbiological characteristics of community-acquired pneumonia among human immunodeficiency virus-infected patients in northern Thailand

Human immunodeficiency virus (HIV) infections are prevalent in Thailand. However, the clinical and microbiological characteristics of community-acquired pneumonia (CAP) in such patients are not completely clear at present. In the present study, we analyzed the characteristics of CAP in 191 HIV-infected patients (192 episodes, 130 males and 61 females, mean age 32.9 years, range: 20-62) who had been admitted to Nakornping Hospital in northern Thailand between December 1996 and January 2002. The mean peripheral blood CD4 lymphocyte count was 68.5/mm3 (range: 0-791). The most common organisms detected in the blood of the subjects were as follows: Penicillium marneffei, 13, Salmonella spp., 5, Cryptococcus neoformans, 4, Staphylococcus aureus, 3, and Rhodococcus equi, 3, and the most common organisms detected in sputum included Haemophilus influenzae, 38, P. marneffei, 10, Streptococcus pneumoniae, 10, R. equi, 9, and S. aureus, 9. Life-threatening meningitis in 5 (cryptococcal in 3 and tuberculous in 2), pneumothorax in 2, and tuberculous lymphadenitis in 1 were also noted, resulting in 21 fatalities (10.9%). The mean peripheral blood CD4 lymphocyte count for cases in which the subject died was 74.8/mm3 (range: 0-340). Logistic regression analysis demonstrated that high age (odds ratio of over 40 years: 15.62) and R. equi infection (odds ratio: 8.14) are related to death of HIV-infected patients with CAP. The above findings indicate that various types of organisms, including mixed organisms, cause CAP in HIV-infected patients in northern Thailand, and high age and R. equi infection seem to be risk factors for death.