Early results of systematic drug susceptibility testing in pulmonary tuberculosis retreatment cases in Cameroon

Abstract

BackgroundThe number of pulmonary tuberculosis (PTB) patients reported with resistance to first-line anti-tuberculosis drugs after a standardized retreatment regimen in Cameroon is increasing. Hence, the National Tuberculosis Control Program (NTP) implemented, in one of the ten Regions of the country, a pilot programme aimed at performing routine drug susceptibility testing (DST) for previously treated PTB cases. The objectives of the programme were to evaluate the feasibility of monitoring drug resistance among retreatment cases under programme conditions and to measure the presence and magnitude of anti-TB drug resistance in order to inform NTP policies.FindingsThis retrospective cohort study was conducted in the Littoral Region of Cameroon in 2009. It included all sputum smear positive (SM+) PTB cases registered for retreatment. TB cases were identified and classified according to World Health Organization (WHO) recommendations for national TB programs. Bacterial susceptibility testing to first-line anti-TB drugs was performed using standard culture methods. In 2009, 5,668 TB cases were reported in the Littoral Region, of which 438 (7.7%) were SM + PTB retreatment cases. DST results were available for 216 (49.4%) patients. Twenty six patients (12%) harbored multi-drug resistant (MDR) strains. Positive treatment outcome rates were particularly low in retreatment patients with MDR-TB (46.2%; 95% CI: 27.1-66.3). Thirteen MDR-TB patients were treated using a standardized MDR treatment regimen. Delivery of laboratory results took on average 17 (12-26) weeks.ConclusionsWHO-recommended routine DST in retreatment patients seems feasible in Cameroon. However, coverage needs to be improved through better management. Moreover, diagnostic delay should be shortened by introducing more rapid diagnostic tools. The high risk of MDR in standard regimen failure cases virtually rules out the standard retreatment regimen for such patients without prior DST.

Drug Resistance Profiles of Mycobacterium tuberculosis Complex and Factors Associated with Drug Resistance in the Northwest and Southwest Regions of Cameroon

“…This was slightly lower (6.67%) than that reported by Assam-Assam et al [17]. Noeske et al [22] reported a 51% of resistance to one or more anti-TB drugs and a 12% MDR rate, among smear positive pulmonary TB re-treatment patients in the Littoral region of Cameroon. MDR-TB from other regions of the world ranges from to 12% - 37% in previously treated cases and 2.1% - 12% in newly diagnosed cases respectively in regions of the Americas, Western Pacific, and European regions [5].…”

Variation and risk factors of drug resistant tuberculosis in sub-Saharan Africa: a systematic review and meta-analysis

“… New and PT patients 416 28.7 1.3 LJ INH, RMP, SM, EMB Ellis Awusu-Dabo et al [ 44 ] 2001-2004 Ghana National survey. New and PT patients 216 25.9 4.7 INH, RMP, SM, EMB, Thiacetazone Jurgen Noesk et al [ 45 ] 2012 Cameroon Sub-national. Twenty-nine TB health facilities in Litoral region.…”

Drug Sensitivity and Molecular Diversity of M. tuberculosis in Cameroon: A Meta-analysis

“…Multidrug-resistance (MDR) was observed only in the South region where it was detected in 1.58% (1/63) isolates. No resistance was recorded for ethambutol (EMB) in the two regions [38,39].…”