Severe Acute Respiratory Syndrome Coronavirus-2 antigen and Immunoglobulin G positivity among residents of South-Central Uganda: September 2021 – August 2022
Year: 2025
Type: preprint
Study design: Observational Study
Abstract: Background: Insights into SARS-CoV-2 in Uganda were limited throughout the epidemic due to incomplete access to diagnostic testing and limited formal surveillance systems. From September 2021 to August 2022, we conducted a household-based surveillance study using both rapid antigen and serologic testing to determine the SARS-CoV-2 infection burden and seroprevalence among residents of South-Central Uganda. Methods: Household members in four communities within the districts of Kyotera and Lyantonde were recruited. Using a structured questionnaire, participants provided sociodemographic and other information. They also provided nasal swabs and blood samples. Swabs were tested using SD Biosensor Standard Q COVID-19 rapid antigen tests. Sera were tested for antibodies to SARS-CoV-2 using the VivaChek Biotech VivaDiag TM IgM/IgG rapid test. We assessed positivity rates overall and by selected socio-demographic characteristics. Modified Poisson regression was used to assess the relationships between IgG seropositivity and antigen positivity, while accounting for clustering by community. Results: From September 2021 to August 2022, 11,113 participants were enrolled. The mean age was 20.6 (SD = 16.1) years, with an average household size of 3.9 (SD = 2.6) persons. Among 11,086 persons tested for SARS-CoV-2 antigen, overall positivity was 0.61%. Among 9,663 participants tested for SARS-CoV-2 antibodies, 6,630 (69%) were IgG-positive. COVID-19 vaccination coverage was 33.4%, and vaccination was significantly associated with IgG seropositivity (aRR = 0.96; 95% CI: 0.94-0.98; p <0.001). Conclusion : We observed high SARS-CoV-2 antigen rapid testing acceptability, low antigen positivity, and moderate IgG seroprevalence in this setting, suggesting low concurrent transmission but significant prior natural infection.
Authors: Charles Ssuuna, Aggrey Anok, Victor Ssempijja, Godfrey Kigozi, Fred Nalugoda, Maria Wawer, Ronald Gray, Larry Chang, Thomas Quinn, Joseph Kagaayi, David Serwadda, Mathew Cotten, Phan, Gertrude Nakigozi, Morgan Otita, Mohammed Lamorde, Stephen Okoboi, Lisa Nelson, Julie Harris, Lisa Mills, Ronald Galiwango, Steven Reynolds
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
OpenAlex ID: W4411521964