Differences in SARS-CoV-2 infections during the first and second wave of SARS-CoV-2 between six ethnic groups in Amsterdam, the Netherlands: A population-based longitudinal serological study

Background Surveillance data in high-income countries have reported more frequent SARS-CoV-2 diagnoses in ethnic minority groups. We examined the cumulative incidence of SARS-CoV-2 and its determinants in six ethnic groups in Amsterdam, the Netherlands. Methods We analysed participants enrolled in the population-based HELIUS cohort, who were tested for SARS-CoV-2-specific antibodies and answered COVID-19-related questions between June 24-October 9, 2020 (after the first wave) and November 23, 2020-March 31, 2021 (during the second wave). We modelled SARS-CoV-2 incidence from January 1, 2020-March 31, 2021 using Markov models adjusted for age and sex. We compared incidence between ethnic groups over time and identified determinants of incident infection within ethnic groups. Findings 2,497 participants were tested after the first wave; 2,083 (83.4%) were tested during the second wave. Median age at first visit was 54 years (interquartile range=44-61); 56.6% were female. Compared to Dutch-origin participants (15.9%), cumulative SARS-CoV-2 incidence was higher in participants of South-Asian Surinamese (25.0%; adjusted hazard ratio [aHR]=1.66; 95%CI=1.16-2.40), African Surinamese (28.9%, aHR=1.97; 95%CI=1.37-2.83), Turkish (37.0%; aHR=2.67; 95%CI=1.89-3.78), Moroccan (41.9%; aHR=3.13; 95%CI=2.22-4.42), and Ghanaian (64.6%; aHR=6.00; 95%CI=4.33-8.30) origin. Compared to those of Dutch origin, differences in incidence became wider during the second versus first wave for all ethnic minority groups (all p-values for interaction<0.05), except Ghanaians. Having household members with suspected SARS-CoV-2 infection, larger household size, and low health literacy were common determinants of SARS-CoV-2 incidence across groups. Interpretation SARS-CoV-2 incidence was higher in the largest ethnic minority groups of Amsterdam, particularly during the second wave. Prevention measures, including vaccination, should be encouraged in these groups. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

This study investigated the cumulative incidence of SARS-CoV-2 and its determinants in six ethnic groups in Amsterdam. The study found that the cumulative incidence of SARS-CoV-2 was higher in South-Asian Surinamese, African Surinamese, Turkish, Moroccan, and Ghanaian participants compared to Dutch-origin participants.