# Seroprevalence of anti-SARS-CoV-2 in patients with hepatitis B and C: a pre-vaccination study

## TL;DR

This study found a high rate of prior SARS-CoV-2 exposure in hepatitis B and C patients before vaccination, especially in older adults and those in disadvantaged areas of Rio de Janeiro.

## Contribution

The study provides new insights into SARS-CoV-2 seroprevalence in hepatitis B and C patients during the pre-vaccination phase of the pandemic.

## Key findings

- 24.1% of hepatitis B and C patients tested positive for anti-SARS-CoV-2 antibodies before vaccination.
- Older individuals (over 40 years) had a higher seroprevalence (16.58%) compared to younger individuals.
- The highest detection rate occurred in November 2020, primarily in impoverished neighborhoods of Rio de Janeiro.

## Abstract

The serological markers for the diagnosis of COVID-19 plays an important role in the epidemiological investigation of the pandemic. This study aims to assess the prevalence of anti-SARS-CoV-2 in hepatitis B and C patients in a pre-vaccination of COVID-19 period. Between March 2020 and January 2021, 199 serum samples from individuals with HBsAg/HBV DNA or anti-HCV/HCV RNA positivity were tested for antibodies (IgM and IgG) against SARS-CoV-2 using Electrochemiluminescent Immunoassay (ECLIA). Among these, 50.3 % (100/199) tested positive for hepatitis C virus infection and 49.7 % (99/199) for hepatitis B virus, confirmed through molecular and serological diagnosis. The anti-SARS-CoV-2 seroprevalence was 24.1 % (48/199) in this population, with 23.23 % (23/99) hepatitis B and 25 % (25/100) hepatitis C patients tested positive for anti-SARS-CoV-2. The higher seroprevalence of anti-SARS-CoV-2 (16.58 %, 33/199) was detected among those over-40 years of age and the month of November 2020 had the highest number of detections 9 % (18/199) with the majority living in impoverished and neglected neighborhoods in the city of Rio de Janeiro. We found a high prevalence of anti-SARS-CoV-2 in patients with viral hepatitis before COVID-19 vaccination. This demonstrates the high exposure of this population during the period of social isolation.