Surveillance of drug-resistant tuberculosis and molecular evaluation of transmission of resistant strains in refugee and non-refugee populations in North-Eastern Kenya

SETTING: Three refugee camp complex clinics and an adjacent non-refugee tre atment centre in North-Eastern Ken ya. OBJECTIVES: To use conventional and molecular epidemiology tools to determi ne: 1) the prevalence of drug resistance in newly diagnosed patients with s mear-positive pulmonary tuberculosis in refugee and non-refugee populations ; 2) risk factors for resistance in the two populations; and 3) whether ISG 6110 restriction fragment length polymorphism (RFLP) and spoligotyping show ed similarities in DNA fingerprinting patterns of drug-resistant isolates t hat could infer transmission within and between the two populations. RESULTS: Of 241 isolates from the camps, 44 (18.3%) were resistant to one o r more drugs, seven of which (2.9%) were multidrug-resistant TB (MDR-TB). O f 88 isolates from the non-refugees, five (5.7%) were resistant to one or m ore drugs without MDR-TB. Drug resistance was higher in the camps than in t he non-refugee population (OR = 3.7; 95%CI 1.42-3.68; P < 0.007). Resistanc e was significantly higher in one camp compared with the other two, despite a comparable ethnic distribution. Unusually, females were more associated with drug resistance than their male counterparts in both populations (OR = 2.3; 95%CI 1.2-4.8; P = 0.008). There was evidence of transmission of stre ptomycin-resistant strains in the refugee population. DNA fingerprints of r esistant strains from the non-refugee population were unique and different from those in the refugee camps. CONCLUSION: The observed high levels of drug resistance and MDR-TB, combine d with evidence of transmission of strains resistant to streptomycin in the refugee population, suggest a need for strengthened TB control programmes in settings with a high risk of developing drug-resistant strains.