Household crowding and mortality before and during the COVID-19 pandemic among adults: Findings from longitudinal population surveillance data in rural and peri-urban settings in Limpopo, South Africa.

BACKGROUND: Household overcrowding is a public health concern linked to increased morbidity and mortality. There is limited data available on the effects of COVID-19 on age-specific mortality in the context of household crowding in rural and peri-urban settings in Africa. Here we assess age-specific excess mortality in densely inhabited households before and during COVID-19. METHODS: We used data collected three times annually between 2019 and 2021 in the health and demographic surveillance project in DIMAMO, South Africa. Data inaccuracies or inconsistencies were identified and corrected using data validation rules or algorithms implemented at both application and database levels. The number of persons-per-room was used to determine the degree of crowding or household crowding index (HCI). HCI tertiles were categorized as low, medium, and high density. RESULTS: Throughout the study, people aged 70 years and above had the highest mortality rates compared to other age groups (40-54 and 55-69), with the highest mortality rates observed in overcrowded households (highest crowding index). MGH was observed as a risk factor for mortality during COVID-19. Individuals aged 70 years and older had the highest hazard ratios before and during COVID-19, where the risk increased during COVID-19 for densely populated households. CONCLUSION: Overcrowding at the household level was associated with increased mortality during COVID-19 for individuals aged 70 years and older. Public health interventions in the case of future pandemics should consider how to address this risk factor.