Prevalence, Social Demographics and Characterization of Hepatitis C Genotypes Circulating Among Injecting Drug Users in Kilifi County, Kenya

Abstract

Hepatitis C virus is a major global health problem estimated to infect over 170 million people globally with the most common route of infection being injecting drug use (IDU). Treatment for HCV infection has traditionally been shown to be genotype specific; however the available drugs are still expensive and out of reach in many developing countries. To improve on monitoring, there is need to continuously document the genotypic burden and epidemiology in different populations. This study aimed to determine HCV prevalence and circulating genotypes and link the data to the socio-demographic characteristics of injecting drug users in Kilifi County along the Kenyan coastline. A cross-sectional survey was conducted among 127 injecting drug users in Watamu, Malindi and Kilifi County. Serology was done for detection of HCV antibodies followed by amplification of HCV RNA using RT-PCR and eventual sequencing of amplified nucleic acid at the ORF conserved region to establish the circulating genotypes. Socio-demographic data was collected using questionnaire administered at the sample collection facilities. In the study, demographic characteristics for Tout/drivers/bodaboda group of IDUs had the highest HCV infection 12(21.8%, OR=1) compared to Beach boy, Fisherman and other IDUs with different occupations. Percentage OR for HCV infection were 1.3 (95% CI: 0.4-4.3) for beach boys, 0.8 (95% CI: 0.2-3.1) for fishermen and 0.9 (95% CI: 0.3-2.6) for IDUs with other occupations. In education, lower primary had 13 (20.0%) infection compared to IDUs with upper primary 6 (16.7%) and secondary and tertiary education 9 (34.6%). Percentage ORs for HCV infection were 1.0 for IDUs with education level of lower primary, 0.8 (95% CI: 0.3-2.3) for upper primary, 2.1 (95% CI: 0.8-5.8) for IDUs with secondary and tertiary education. A total of 28 (23 males and 5 females) samples out of 127 samples were positive for HCV giving a sero-prevalence of 22.1%. 11 (39.3%) samples, all from the male participants were detected as antibody positive PCR positive, showing potential for acute infection and the remaining 17 (60.7%) antibody positive PCR negative. The most prevalent genotype was genotype 4a accounting for 87% with genotype 1a accounting for the remaining 13%. Kilifi town only recorded genotype 4a with Watamu and Malindi towns recoded multiple genotypes of 1a and 4a. Phylogenetic analysis established 100% concordance between the local strains and strains from, Portugal, France, Egypt, Cyprus, Southeast Asia, Middle East, Saudi Arabia, America, Japan, Indonesia, China and India. In the study, prevalence of HCV infection among IDUs in Kilifi County is not reducing despite the fact that a lot of investment has been put on harm reduction strategies such as the needle exchange programs; the study also reveals a potential importation of genotype 4a which has been previously considered foreign in the region. Finally, this study recommends continuous molecular surveillance of circulating HCV genotypes among Injecting drug users which act as a bridge of infection to the general population.