Tuberculosis in Arvlbulatory HIV-infected patients in Dar es Salaam, Tanzania: prevalence, etiological mycobacterial species and their susceptibility to first-line anti-tb drugs

Abstract

. Background: The HIV pandemic has led to a resurgence of tuberculosis, and with it, increased need for prompt and appropriate diagnosis, treatment and management of tuberculosis in HIV- '--- infected individuals. Objectives: To determine, among ambulant HIV infected individuals in Oar es Salaam, the prevalence of tuberculosis, aetiological mycobacterial species and their susceptibility to first-line anti-T'B drugs. Methodology: During the study period, January to June 2004, a total of 5064 sputum specimens from 1688 known HIV infected patients, 473 (28%) males and 1215 (72%) females, aged between 18 and 70 years (mean 44 years) were examined by microscopy and growth on Lowenstein Jensen medium. Positive cultures were identified to species level by growth and biochemical characteristics. Drug susceptibility was performed by the conventional proportional method to four first line TB drugs- rifampicin, ethambutol, isoniazid and streptomycin. Results: The prevalence of tuberculosis was 5.2%. Majority (53.8%) of the isolates were M tuberculosis, most of which (89.3%) were fully sensitive to the first line anti-tuberculous drugs. Mfortitum and other NTM were isolated from ten (19.2%) and nine (17.3%) patients respectively. Five (9.7%) isolates were untypable .MDR was 3.6 %,66.7%,90%, and 20% for MTB, NTM, M fortitum and untypable isolates. Conclusion: In this population of ambulant HIV patients, with CD 4 counts 2: 200 cells/ml, the prevalence of tuberculosis was low (5.2%) and was not correlated with CD4 counts. Majority (53.8%) of the isolates were M tuberculosis and were fully sensitive to the first line drugs with only one isolate (3.6%) being multi drug resistant. Recommendations: There is a need for simple and rapid techniques for identification and speciation of mycobacteria and for anti-TB drug sensitivity surveillance. The high isolation rate of NTM needs to be investigated further.