Causes of lower respiratory infection in HIV-infected Ugandan adults who are sputum AFB smear-negative.

SETTING: Mulago national referral and teaching hospital.
OBJECTIVE: To assess the etiology of lower respiratory infections in HIV-infected Ugandan adults who are sputum acid-fast bacilli (AFB) smear-negative.
DESIGN: A descriptive cross-sectional study. Participants included consecutive adult patients admitted to medical wards with respiratory symptoms of at least 3 weeks and infiltrates on chest radiograph. Those who were sputum AFB smear-negative and HIV-positive underwent bronchoscopy and bronchoalveolar lavage (BAL). BAL fluid was obtained and stained for AFB and Pneumocystis carinii, and cultured for bacteria and fungi.
RESULTS: Of 198 patients screened, 48 were sputum smear-positive for AFB. Sixty-seven were excluded for various reasons, leaving 83 patients who met the inclusion criteria and underwent bronchoscopy: 32 (38.6%) patients had P. carinii infection, 20 (24%) had pulmonary tuberculosis, nine (11%) had pulmonary Kaposi's sarcoma and pyogenic bacteria were identified in seven (8%). No aetiological diagnosis was found in 24 (30%) patients.
CONCLUSION: P. carinii and Mycobacterium tuberculosis were the commonest causes of disease among sputum AFB smear-negative, HIV-positive adults presenting to Mulago Hospital. Pulmonary Kaposi's sarcoma and pyogenic bacteria occurred with less frequency.