Background: Prevalence of hepatitis C virus and that of its main genotypes varies between the worlds geographic regions. The risk factors for infection with HCV include blood transfusion, tattoing and injecting drug use.Objectives: To examine the prevalence of HCV and determine its main genotypes among a cohort of drug users in Kenya.Design: A laboratory based study.Setting: Hepatitis research laboratory in the Centre for Virus Research at the Kenya Medical Research Institute, Nairobi.Subjects: Three hundred and fourteen male and 19 female intravenous and non-intravenous drug users aged between 15-55 years.Results: Seventy four (22.2%) out of 333 samples tested positive for anti-HCV. Sixty nine out of the 74 serum samples were assayed for HCV RNA and 38 (55.5%) were positive. The RNA positive samples were further subjected to sequencing and 19 (73%) of the samples were classified asgenotype la, while seven (27%) samples were classified as genotype 4. Genotypes 2, 3, 5 and 6 were not identified in this study.Conclusions: These results demonstrate a high HCV infection prevalence among this cohort of drug users (22.2 %) as compared to that of the general population, which is estimated to be 0.2- 0.9%. The study also confirms the presence of at least two major genotypes among Kenyan drugusers (genotypes 1 and 4)
