Uzoewulu Ngozi G
University of Benin,Nigeria
Uzoewulu Ngozi G obtained his PhD in Medical Microbiology and Diploma in Medical Laboratory Science with specialty in Medical Parasitology from University of Benin, Edo state and University of Nigeria Enugu respectively. He is now working in Department of Medical Microbiology and Parasitology Nnamdi Azikiwe University Teaching Hospital Nnewi Anambra state, Nigeria as a Microbiologist.
Background: Diagnosis of tuberculosis (TB) amongst HIV patients is a great challenge due to the low density of Acid Fast bacilli (AFB) in their sputum. Objective: The study was conducted to determine the sensitivity of direct smear microscopy (DSM) for TB diagnosis in HIV endemic setting using culture as a gold standard. Method: Sputum specimen of 550 TB suspects were screened microscopically for AFB using Ziehl-Nielsen method at NAUTH Nnewi and positive samples subjected to culture on Lowenstein-Jensen medium with each patient also screened for HIV status. Result: They comprised of 238 (43%) DSM TB positive cases and 312 (57%) DSM TB negative cases. Out of 238 DSM TB positive cases, 180(33%) were culture positive cases with 12(2.1%) culture negative cases, 13(2.4%) contaminated specimen, 3(0.5%) NTM and 30(5.5%) lost specimen resulting in 58 (10.5%) specimen which were excluded from analysis respectively. Among the 180 culture positive TB cases 34(19%) were HIV-positive patients while 146(81%) were HIV Negative culture positive TB cases, 109(61%) males as compared to 71(39%) females within 21-40 years age group mostly affected. Findings from this study showed that the difference in the detection of PTB between these two methods was statistically significant (p=0.0001), identifying high sensitivity case detection rate of DSM as compared to specificity by culture detection more especially in HIV positive persons. Conclusion: To improve TB case detection for effective treatment, we recommend the use of culture as back up to enhance the specificity and accuracy of DSM especially in HIV positive persons.