ONE HEALTH EPIDEMIOLOGY OF HEPATITIS C VIRUS IN PAKISTAN: INTEGRATING PREVALENCE, GENOTYPE DIVERSITY, MOLECULAR EVOLUTION, AND TRANSMISSION RISK

Abstract

Pakistan has one of the world's highest burdens of blood borne infections of the hepatitis C virus (HCV) and has a major public health problem. In this review, we summarize the current state of epidemiological evidence on HCV in Pakistan, including the ecological niche and molecular evolution of HCV in Pakistan, from a One Health perspective. Genotype 3a is the predominant genotype, representing around 55-65% of infections, and with notable regional variations, while there is an alarming rate of untypeable infections (21.3%) and mixed infections (3.5%). Epidemic expansion of HCV 3a in South Asia dates back to the twentieth century and has reached saturation in diversity, with >100 years of circulation in the region. Various factors such as HACE, community practices like barbering and personal service rituals, occupational exposures and intrafamilial spread contribute to the dynamics of transmission. HCV is an indicator of a number of systemic weaknesses in infection control, informal healthcare, and socioeconomic factors. Combined with genomic surveillance, spatial epidemiology and risk mapping could provide a roadmap for precision elimination policy, however the coverage of such datasets is fragmented and the available longitudinal genomic data are limited.