SARS-CoV-2 infections in migrants and the role of household overcrowding: A causal mediation analysis of Virus Watch data

Abstract

Background: Migrants are over-represented in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections globally; however, evidence is limited for migrants in England and Wales. Household overcrowding is a risk factor for SARS-CoV-2 infection, with migrants more likely to live in overcrowded households than UK-born individuals. We aimed to estimate the total effect of migration status on SARS-CoV-2 infection and to what extent household overcrowding mediated this effect. Methods: We included a sub-cohort of individuals from the Virus Watch prospective cohort study during the second SARS-CoV-2 wave (1st September 2020-30th April 2021) who were aged at least 18 years, self-reported the number of rooms in their household and had no evidence of SARS-CoV-2 infection pre-September 2020. We estimated total, indirect and direct effects using Buis logistic decomposition regression controlling for age, sex, ethnicity, clinical vulnerability, occupation, income and whether they lived with children. Results: In total, 23,478 individuals were included. 9.07% (187/2,062) of migrants had evidence of infection during the study period versus 6.27% (1,342/21,416) of UK-born individuals. Migrants had 22% higher odds of infection during the second wave (total effect; OR:1.22, 95%CI:1.01-1.47). Household overcrowding accounted for approximately 32% of these increased odds (indirect effect, OR:1.07, 95%CI:1.03-1.12; proportion accounted for: indirect effect[7]/total effect[22]=0.32). Conclusion: Migrants had higher odds of SARS-CoV-2 infection during the second wave compared with UK-born individuals and household overcrowding explained 32% of these increased odds. Policy interventions to reduce household overcrowding for migrants are needed as part of efforts to tackle health inequalities during the pandemic and beyond.

Tracking Covid-19 in England and Wales: Insights from Virus Watch - A Prospective Community Cohort Study

“…This will facilitate monitoring and response capabilities not only for COVID-19 but also other acute respiratory infectious diseases in the future. multiple clinical risk factors and studying of symptom profiles associated with different SARS-CoV-2 variants of concern [17][18][19][20][21][22][23][24][25][26].…”

Tracking COVID-19 in England and Wales: Insights from Virus Watch - a prospective community cohort study

“…It also improved the reliability of the results by reducing the risk of underestimating COVID-19 incidence associated with the selfreporting of PCR/LFT test results (Figure 2A and 2B). In comparison to the ONS CIS and the national testing programme, our approach allowed the collection and analysis of multiple clinical risk factors and studying of symptom profiles associated with different SARS-CoV-2 variants of concern [17][18][19][20][21][22][23][24][25][26].…”