Diagnostic system strengthening for drug resistant tuberculosis in Nigeria: impact and challenges

Background: The increasing prevalence of drug-resistant tuberculosis and the threat of extensively-drug-resistant tuberculosis in HIV hotspots have made the detection and treatment of drug-resistant tuberculosis in the sub-Saharan Africa setting a global public health priority. Objective: We sought to examine the impact and challenges of tuberculosis diagnostic capacity development for the detection of drug-resistant tuberculosis and bio-surveillance using a modular biosafety level 3 (BSL-3) laboratory in Nigeria. Method: In 2010, the United States President’s Emergency Plan for AIDS Relief (PEPFAR) programme, through the Institute of Human Virology at the University of Maryland in Baltimore, Maryland, United States, deployed a modular, BSL-3 laboratory to support the national tuberculosis programme in drug-resistant tuberculosis detection and bio-surveillance for effective tuberculosis prevention and control. Results: From 2010 until present, sputum samples from 11 606 suspected cases in 33 states were screened for drug-resistant tuberculosis. Of those, 1500 (12.9%) had mono-resistant tuberculosis strains, and 459 (4.0%) cases had multidrug-resistant tuberculosis. Over the lastfour years, 133 scientists were trained in a train-the-trainer programme on advanced tuberculosis culture, drug susceptibility testing, line-probe assays and Xpert® MTB/RIF, in addition to safety operations for biosafety facilities. Power instability, running cost and seasonal dust are notable challenges to optimal performance and scale up. Conclusion: Movable BSL-3 containment laboratories can be deployed to improve diagnostic capacity for drug-resistant tuberculosis and bio-surveillance in settings with limited resources

Mycobacterial Etiology of Pulmonary Tuberculosis and Association with HIV Infection and Multidrug Resistance in Northern Nigeria

Objective. Data on pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) complex in Nigeria are limited. We investigated species of MTB complex in TB cases from northern Nigeria. Methods. New TB suspects were enrolled, screened for HIV and their sputum samples were cultured after routine microscopy. Genotypes MTBC and MTBDRplus were used to characterize the MTB complex species and their resistance to isoniazid and rifampicin. Results. Of the 1,603 patients enrolled, 375 (23%) had MTB complex infection: 354 (94.4%) had Mycobacterium tuberculosis; 20 (5.3%) had Mycobacterium africanum; and one had Mycobacterium bovis (0.3%). Cases were more likely to be male (AOR = 1.87, 95% CI : 1.42–2.46; P≤0.001), young (AOR = 2.03, 95% CI : 1.56–2.65; P≤0.001) and have HIV (AOR = 1.43, 95% CI : 1.06–1.92; P=0.032). In 23 patients (6.1%), the mycobacterium was resistant to at least one drug, and these cases were more likely to have HIV and prior TB treatment (AOR = 3.62, 95% CI : 1.51–8.84; P=0.004; AOR : 4.43; 95% CI : 1.71–11.45 P=0.002 resp.), compared to cases without any resistance. Conclusion. Mycobacterium tuberculosis remained the predominant specie in TB in this setting followed by Mycobacterium africanum while Mycobacterium bovis was rare. The association of TB drug resistance with HIV has implications for TB treatment