Tuberculosis in Sudan: a study of Mycobacterium tuberculosis strain genotype and susceptibility to anti-tuberculosis drugs

Abstract

BackgroundSudan is a large country with a diverse population and history of civil conflict. Poverty levels are high with a gross national income per capita of less than two thousand dollars. The country has a high burden of tuberculosis (TB) with an estimated 50,000 incident cases during 2009, when the estimated prevalence was 209 cases per 100,000 of the population. Few studies have been undertaken on TB in Sudan and the prevalence of drug resistant disease is not known.MethodsIn this study Mycobacterium tuberculosis isolates from 235 patients attending three treatment centers in Sudan were screened for susceptibility to isoniazid, rifampicin, ethambutol and streptomycin by the proportion method on Lowenstein Jensen media. 232 isolates were also genotyped by spoligotyping. Demographic details of patients were recorded using a structured questionnaire. Statistical analyses were conducted to examine the associations between drug resistance with risk ratios computed for a set of risk factors (gender, age, case status - new or relapse, geographic origin of the patient, spoligotype, number of people per room, marital status and type of housing).ResultsMulti drug-resistant tuberculosis (MDR-TB), being resistance to at least rifampicin and isoniazid, was found in 5% (95% CI: 2,8) of new cases and 24% (95% CI: 14,34) of previously treated patients. Drug resistance was associated with previous treatment with risk ratios of 3.51 (95% CI: 2.69-4.60; p < 0.001) for resistance to any drug and 5.23 (95% CI: 2.30-11.90; p < 0.001) for MDR-TB. Resistance was also associated with the geographic region of origin of the patient, being most frequently observed in patients from the Northern region and least in the Eastern region with risk ratios of 7.43 (95%CI:3.42,16.18; p: < 0.001) and 14.09 (95%CI:1.80,110.53; p:0.026) for resistance to any drug and MDR-TB. The major genotype observed was of the Central Asia spoligotype family (CAS1_Delhi), representing 49% of the 232 isolates examined.ConclusionsWe conclude that emergence of drug resistant tuberculosis has the potential to be a serious public health problem in Sudan and that strengthened tuberculosis control and improved monitoring of therapy is needed. Further surveillance is required to fully ascertain the extent of the problem.

Rifampicin-resistance pattern of Mycobacterium tuberculosis and associated factors among presumptive tuberculosis patients referred to Debre Markos Referral Hospital, Ethiopia: a cross-sectional study

“…In the present study, the proportion of rifampicin-resistant M. tuberculosis was significantly higher among previously treated patients compared to treatment naive patients which might be due to failure from previous treatment and contact with drug resistant TB patients [26, 38–43]. However, the level of rifampicin resistance among previously untreated cases (6.7%) in the analysis close to the reported prevalence of rifampicin- resistant MTB (10.4%).…”

Mycobacterium tuberculosis Lineage 7 Strains Are Associated with Prolonged Patient Delay in Seeking Treatment for Pulmonary Tuberculosis in Amhara Region, Ethiopia

“…Another study from Ethiopia reported 38.9% CAS strains (8), and CAS/Delhi was the predominant lineage in a study from Sudan (32). CAS/Delhi strains have been circulating in Central Asia, the Middle East, Saudi Arabia (33) and India (34) for a long time.…”

Frequency of mutations in the rpoB gene of multidrug-resistant Mycobacterium tuberculosis clinical isolates from Sudan

“…Mycobacteria laboratory facilities in Sudan exist only in Khartoum state whereas TB patients from other states are referred to Khartoum state for diagnosis and treatment. The MDR-TB prevalence in Sudan was found in 5% of new cases and 24% of previously treated patients [3]. Recent development of the Xpert MTB/RIF test [4] and of the line probe assay [5] which span 81-bp fragment of the RNA polymerase beta subunit (rpoB) gene have allowed for the rapid detection of resistance to rifampicin (RIF).…”