Prevalence of SARS-CoV-2 antibodies in the Mozambican population: a cross-sectional Serologic study in three cities, July-August 2020

Abstract

Background

The extent of population exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was uncertain in many African countries during the onset of the pandemic.

Methods

We conducted a cross-sectional study and randomly selected and surveyed general population and occupational groups from July 6 to August 24, 2020, in three cities in Mozambique. Anti-SARS-CoV-2 specific immunoglobulins M and G antibodies were measured using a point-of-care rapid test. The prevalence was weighted for population (by age, sex, and city) and adjusted for test sensitivity and specificity.

Results

A total of 21,183 participants, including 11,143 from the general population and 10,040 from occupational groups, were included across all three cities. General population seropositivity (immunoglobulins M or G) prevalence was 3.0% (95% CI, 1.0–6.6) in Pemba, 2.1% (95% CI, 1.2–3.3) in Maputo City, and 0.9% (95% CI, 0.1–1.9) in Quelimane. The prevalence in occupational groups ranged from 2.8% (95% CI, 1.3–5.2) to 5.9% (95% CI, 4.3–8.0) in Pemba, 0.3% (95% CI, 0.0–2.2) to 4.0% (95% CI, 2.6–5.7) in Maputo City, 0.0% (95% CI, 0.0–0.7) to 6.6% (95% CI, 3.8–10.5) in Quelimane, and showed variations between the groups tested.

Conclusions

Exposure to SARS-CoV-2 was extensive during the first pandemic wave, and transmission may have been more intense among occupational groups. These data have been of utmost importance to inform public health intervention to control and respond to pandemic in Mozambique.

Previous presentations of findings

Results from this study were presented (in Portuguese) at the Mozambican Jornadas Nacionais de Saúde in Maputo, Mozambique on Aug 10, 2021 (abstract #108, title, Prevalência da exposição ao novo coronavírus em três cidades de Moçambique, Julho-Agosto de 2020).