Prevalence and risk factors for hepatitis C virus infection in an informal settlement in Karachi, Pakistan

Munazza Mansoor; William A de Glanville; Ridwa Alam; Khawar Aslam; Mubashir Ahmed; Petros Isaakidis; Aneeta Pasha

doi:10.1371/journal.pgph.0002076

Prevalence and risk factors for hepatitis C virus infection in an informal settlement in Karachi, Pakistan

PLOS Glob Public Health. 2023 Sep 20;3(9):e0002076. doi: 10.1371/journal.pgph.0002076. eCollection 2023.

Authors

Munazza Mansoor¹, William A de Glanville², Ridwa Alam¹, Khawar Aslam², Mubashir Ahmed², Petros Isaakidis³, Aneeta Pasha¹

Affiliations

¹ Interactive Research and Development (IRD), Karachi, Pakistan.
² Médecins Sans Frontières (MSF), Brussels, Belgium.
³ Southern Africa Medical Unit, Médecins Sans Frontières, Cape Town, South Africa.

Abstract

The burden of hepatitis C virus (HCV) infection in Pakistan is amongst the highest in the world. People living in slums are likely to be at high risk of infection. Here, we describe the results of a cross-sectional survey conducted in March 2022 that aimed to quantify the prevalence of HCV infection in Machar Colony, one of the largest and oldest slum settlements in Karachi. Risk factors for HCV seropositivity were identified using multi-level logistic regression. We recruited 1,303 individuals in a random selection of 441 households from Machar Colony. The survey-adjusted HCV-seroprevalence was 13.5% (95% Confidence Interval (CI) 11.1-15.8) and survey-adjusted viraemic prevalence was 4.1% (95% CI 3.1-5.4) with a viraemic ratio of 32% (95% CI 24.3-40.5). Of 162 seropositive people, 71 (44%) reported receiving previous treatment for chronic hepatitis C. The odds of HCV seropositivity were found to increase with each additional reported therapeutic injection in the past 12 months (OR = 1.07 (95% Credible Interval (CrI) 1.00-1.13)). We found weaker evidence for a positive association between HCV seropositivity and a reported history of receiving a blood transfusion (OR = 1.72 (95% CrI 0.90-3.21)). The seroprevalence was more than double the previously reported seroprevalence in Sindh Province. The overall proportion of seropositive people that were viraemic was lower than expected. This may reflect the long-term impacts of a non-governmental clinic providing free of cost and easily accessible hepatitis C diagnosis and treatment to the population since 2015. Reuse of needles and syringes is likely to be an important driver of HCV transmission in this setting. Future public health interventions should address the expected risks associated with iatrogenic HCV transmission in this community.

Copyright: © 2023 Mansoor et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Grants and funding

This Project was funded by Foundation for Innovative New Diagnostics. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.