Seroprevalence of SARS-CoV-2 in wet market workers in Dhaka, Bangladesh in 2022

Objectives

We assessed the transmission of SARS-CoV-2 and vaccine receipt in a representative sample of wet market workers in a highly dense, low-income setting. Wet markets are key in many Asian settings, including Dhaka, Bangladesh, for fresh food, including animal protein.

Methods

During early 2022, we assessed the prevalence of anti-SARS-CoV-2 antibodies in a random sample of poultry and vegetable workers in 15 wet markets, and investigated associations with socio-demographic characteristics and COVID-19 vaccination.

Results

In the 204 poultry workers and 87 vegetable sellers recruited, COVID-19 vaccine uptake was similar (69% vs 67%). The most common vaccines were whole inactivated vaccines (Sinopharm or Sinovac; 44%). Nearly all (99%) participants were positive for anti-SARS-CoV-2 spike antibodies. Anti-SARS-CoV-2 nucleocapsid antibodies, indicative of recent infection, was 59.4% (95% confidence interval 54.7-64.0%). There was no evidence that the latter was associated any characteristics, except vaccination (adjusted odds ratio 0.49; 95% confidence interval 0.23-1.02; P = 0.093).

Conclusions

The ubiquity of anti-spike and high prevalence of anti-nucleocapsid antibodies were consistent with high transmission after three previous pandemic waves. Wet markets have a potential role amplifying transmission of airborne pathogens, such as SARS-CoV-2 and Avian Influenza Viruses, and an important public-facing hotspot for close monitoring for future emerging infections.