Mycobacterium bovis Prevalence in Humans Does Not Differ between Regions in Burkina Faso

Background: In 1996, tuberculosis detection rate was higher in Oudalan (Sahel region) than in other provinces in Burkina Faso. Cattle breeding, a major activity of the local population, may favor exposure of humans to bovine tuberculosis. Objectives: (i) to isolate and identify M. bovis among new cases of tuberculosis with positive culture in the Sahel (Gorom-Gorom and Dori); the Center (Ouagadougou) and the Western (Bobo-Dioulasso) regions of the country; (ii) to investigate susceptibility of isolated strains to anti-tuberculosis. Methods: (i) collection of sputum from newly TB patients with a positive smear during a prospective study carried out in 1998 in the North, Central and Western region of the country and transferred at the Mycobacteriology Laboratory, (ii) optimization of operational procedures: (iii) mycobacteria strains's isolation on 3 different media (Loweinstein Jensen (LJ), LJ without glycerine and LJ supplemented with pyruvate; (iv) identification of the tuberculosis complex according to criteria such as: bacillus growth time, colony appearance, biochemical test results, bacilli growth with pyrazinamide or thiophene carboxylate hydrazide, or D-cycloserine; (v) performing antibiograms. Results: Among the isolated strains, M. bovis represented 6.2% (2/30) in Gorom-Gorom, 0% (0/18) in Dori, 2.6% (3/109) in Ouagadougou and 2.9% (2/65) in Bobo-Dioulasso. Sixty nine percent (31/45) of strains were susceptible to the main anti-tuberculosis drugs, 13 strains presented single or combined resistance and one strain was multidrug-resistant. Conclusion: We showed that M. bovis disease is prevalent in all the studied regions but at a relatively low rate. The transhumance of from the north to the west practiced by the breeders could explain why it was found M. bovis in a similar rate as in Ouagdougou and Bobo-Dioulasso where livestock activity is less intense than in Gorom-Gorom.