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).