Estimate of vertical transmission of Hepatitis C virus in Pakistan in 2007 and 2012 birth cohorts

Abstract

Despite a combination of high Hepatitis C virus (HCV) prevalence, a large adult population and high fertility, no published estimates of the scale and contribution of vertical transmission to HCV incidence in Pakistan exist. The objective of this study was to estimate the number of new HCV infections occurring in Pakistan as a result of vertical transmission. We adapted a published mathematical model based on HCV antibody and viraemia prevalence, fertility rates, risk of HCV vertical transmission and children mortality rates to estimate the number of infections in the 2007 and 2012 birth cohorts nationally and in four subnational regions. We estimated that 19 708 (95% uncertainty interval [UI]: 15 941-23 819) children were vertically infected by HCV in 2007 and 21 676 (95% UI: 17 498-26 126) in 2012. The majority of these cases (72.9% and 72.5% in 2007 and 2012, respectively) occurred in Punjab. We estimated that vertical transmission as a mode of exposure accounted for a quarter of HCV infections among children under 5 years of age (25.2% in 2007 and 24.0% in 2012).

Conclusion: Our results showed that one in 260 children born in Pakistan in 2007 and 2012 acquired HCV vertically. While currently no interventions during pregnancy and childbirth are recommended to reduce this risk, prevention, testing and treatment strategies should be considered to reduce the burden of vertical HCV infections among young children. Other routes of transmission appear to contribute the majority of HCV infections among children and must also be clarified and urgently addressed.

Keywords: infant; infectious disease transmission; mother-to-child transmission; pregnancy; transmission routes.