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

BACKGROUND: Sudan 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. METHODS: In 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). RESULTS: Multi 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. CONCLUSIONS: We 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

The lower and middle Berriasian in Central Tunisia: Integrated ammonite and calpionellid biostratigraphy of the Sidi Kralif Formation

The lower and middle Berriasian sedimentary succession of the Sidi Kralif Formation has been a subject of biostratigraphic study in two key sections in Central Tunisia. Our contribution is an attempt to better define the basal Berriasian interval, between the Berriasella jacobi Zone and the Subthurmannia occitanica Zone. Zonal schemes are established using ammonites and calpionellids, and these permit correlation with other regions of Mediterranean Tethys and beyond. The use of biomarkers afforded by microfossil groups has allowed characterization and direct correlation with four widely accepted calpionellid sub-zones, namely Calpionella alpina, Remaniella, Calpionella elliptica and Tintinopsella longa. The two ammonite zones of Berriasella jacobi and of Subthurmannia occitanica are recognised on the basis of their index species. The parallel ammonite and calpionellid zonations are useful as a tool for correlation and calibration in time and space, thus allowing a better definition of a J/K boundary. The presence of four Berriasian calpionellid bioevents is recognised: (1) the ‘explosion’ of Calpionella alpina, (2) the first occurrence of Remaniella, (3) the first occurrence of Calpionella elliptica and (4) the first occurrence of Tintinopsella longa. The last is here documented as coeval with the presence of Subthurmannia occitanica, which marks the lower/middle Berriasian boundary

The early Middle Pleistocene archeopaleontological site of Wadi Sarrat (Tunisia) and the earliest record of Bos primigenius

10.1016/j.quascirev.2014.02.01