Abstract:
Drug resistant tuberculosis occurs when Mycobacterium tuberculosis (MTB) organisms become resistant to antimicrobial agents at the levels attainable in blood and tissue. This is a major challenge in tuberculosis care and control. Scarce data exists in areas with high rates of tuberculosis and Human Immunodeficiency Virus co- infection. The study aimed at determining first line anti-TB drug resistance. A cross-sectional study was conducted among new and re-treatment HIV infected pulmonary tuberculosis patients fifteen years and older in Nairobi, Kenya in 2013. A total of 215 patients were enrolled for the study. One hundred and thirty eight results were analyzed, 79 (57.2%) were male and 59 (42.8%) female. New cases were 34% while 66% were retreatment cases. Sputa with bacteriologically confirmed pulmonary tuberculosis were cultured on Mycobacterium Growth Indicator Tube media. Strains of MTB complex were subjected to drug susceptibility testing for isoniazid, rifampicin, streptomycin, and ethambutol using the proportional method on (MGIT). Forty three (31.2%) isolates showed resistance to at least any one drug tested, while 112 (81.2%) were susceptible. Resistance to any one drug tested regarding treatment status, showed high resistance to isoniazid in re-treatments and none to new cases (17.6% and none) respectively. Six (6.6%) and none were multi drug resistant among retreatment and new cases respectively. Analysis of CD4 count revealed a median CD4 count of 286 cells /μl, indicating advanced H.I.V disease. Resistance pattern among patients with CD4 count of < 200 cells /µl and CD4 >200 cells /µl, showed high resistance to isoniazid 6 (11.8%) and 10 (11.5%) respectively. Three (5.9%), and 3(3.4%) isolates, had multidrug resistance against isoniazid and rifampicin. There were no significant associations between the various resistant patterns and levels of CD4. The study revealed high levels of drug resistance among those previously treated. This implies that the drug resistant strains are not passed to the new cases.
