Diagnostic yield and grading of acid-fast bacilli from serial sputum smears of HIV-infected and uninfected tuberculosis patients in routine microscopy laboratory in Ouagadougou, Burkina Faso

Abstract

Abstract: We compared 100 HIV-infected and 100 non-infected adult patients with pulmonary tuberculosis (TB) to evaluate the association between the HIV status and the microscopic yield, and between the HIV status and the grading of acid-fast bacilli (AFB) sputum smears. We stained specimens by Ziehl-Neelsen hot method. The first serial sputum smears diagnosed 89% HIVinfected and 94% uninfected. The additional yields of the second and third sputum smears identified respectively 10% and 1% among the HIV-infected against 5% and 1% among the patients without HIV. Considering grading of AFB, the HIVpositive patients were more scanty and less positive 2+ and 3+ at the first (P=0.089) and the second sputum smears (P=0.010). For the second AFB-smears grading, there was a significant difference between HIV-infected and uninfected among the males (P=0.031), the group of age ranging from 15 to 44 years old (P=0.003) and among the ambulatory patients (P=0.015); when we analyzed data for subgroups by HIV serological status, the difference was not significant in the results among the females (P=0.417) and the TB-hospitalized (P=0.501). In conclusion, the morning sputum smears improved the diagnostic yield in both HIV-infected and uninfected patients. However, globally the frequency of scanty was significantly associated with HIV serological status.