Drug resistance profiles of new- and previously treated patients with pulmonary tuberculosis in Ibadan, Nigeria.

BACKGROUND: Information on TB drug resistance profiles and its' associated risk factors are scarce in Nigeria despite the large burden of disease in the country. The study was designed to report drug resistance profiles of new- and previously treated patients with pulmonary tuberculosis (TB) in Ibadan, Nigeria. METHOD: Sputum from consenting pulmonary TB patients were collected and cultured for Mycobacterium tuberculosis (Mtb) at the TB laboratory of the University College Hospital, Ibadan, Nigeria using standard method. Mtb were stored and sent for drug susceptibility testing against first and second-line anti-TB drugs at the MRC Unit, The Gambia and at the Institute of Tropical Medicine, Antwerp, Belgium using BACTEC MGIT 960 and proportion method on solid medium respectively. RESULTS: Of 238 Mtb collected, 124 (52.1%) were viable, 102 (59.65%) non-viable while 12 (7.02%) were contaminated. About half (58.87%) of the Mtb were from previously treated patients, 40 (32.26%) were from new patients while treatment history of 1.1 (8.87%) were unknown. Forty-seven (37.90%) of the 124 Mtb. tested were multidrug resistant (MDR) out of which, 40 (85.10%) were from previously treated patients.. HIV prevalence was 8.69%. Of the 17 MDR-TB from previously treated cases tested for second-line drugs, four (23.53%) were resistant to fluoroquinolones or injectable agents, 13 (76.47%) were susceptible while none was resistant to both of these classes of drugs. CONCLUSION: MDR-TB in Ibadan already demonstrates resistance to second line anti-TB drugs hence management of MDR-TB patients should be strengthened to prevent emergence of extensively drug-resistant TB (XDR-TB).

Molecular diagnosis of MDR-TB using GenoType MTBDRplus 96 assay in Ibadan, Nigeria.

Multidrug resistant Mycobacterium tuberculosis (MDR-TB) is of great public health importance worldwide. This three month laboratory- based study (1st September-30th November, 2011) was carried out at the TB laboratories of the University College Hospital, Ibadan, Nigeria to determine the magnitude of MDR-TB using molecular based GenoType MTBDRplus 96 assay. Two sputum samples were collected from each subject. These were processed using Ziehl -Neelsen (ZN) reagents. The sputa were cultured on Loewenstein-Jensen egg -based medium and incubated at 370C for eight weeks. Mycobacterium tuberculosis complex (MTBC) was confirmed by colonial morphology and repeat ZN staining. All the Acid-fast bacill (AFB) positive smears and culture positive isolates were tested for genetic identification and drug susceptibility testing (DST) using PCR- based GenoType MTBDRplus 96 assay (HAINs Lifesciences, GmbH, Nehren, Germany) according to manufacturers' instructions. Of the 68 samples processed, 11 (16.2%) were AFB positive while six (8.8%) were positive for culture. Eleven (64.7%) out of the 17 samples tested for genetic identification were MTBC while six were Non Tuberculosis Mycobacteria (NTM). All NTM were from AFB positive sputum while none was from culture positive isolates. Of the six culture isolates tested for DST, three (33.3%) were susceptible to isoniazid and rifampicin; one (16.7%) showed mono-resistance to isoniazid while two (30.0%) were resistant to the two drugs. This study shows that MDR-TB is present in Ibadan. There is a need to make DST diagnostic facilities more available and accessible in Nigeria.