ABSTRACT
Background: In Africa, the 9.3 million COVID-19 cases and 174,993 related deaths reported between 2020 and 2022 are underestimated given the limited testing and reporting capacity. Mass testing with antigen-detecting rapid diagnostic tests (Ag-RDTs), including testing of asymptomatic individuals, is expected to improve the identification of SARS-CoV-2 infections and enable immediate clinical management, isolation of patients, contact tracing, and quarantining of contacts. We offered mass Ag-RDT testing in large gatherings to determine the SARS-CoV-2 case detection rate, acceptance of mass testing, the prevalence of circulating variants, and the cost of implementation. Method(s): In 49 high-attendance facilities in Kiambu County identified as possible points of community-based transmission, individuals two years old and older were offered COVID-19 testing and vaccination. Those accepting testing were enrolled in the study after providing written informed consent. A questionnaire was administered and a nasopharyngeal swab was collected. Those testing positive and those testing negative but with COVID-19 symptoms were referred for PCR testing and genome sequencing. Data were analyzed using descriptive statistics. The total cost of implementing the community testing was estimated from a health system perspective using a micro-costing method. Result(s): From June-September 2022, 4,062 individuals were offered testing (mean age 39 years, 2,114 (58.6%) were male). The testing acceptance was 78.1% (3,174/4,062) 95%CI, 76.9%-79.5%). The case detection rate was 34/3,174 (1.07%: 95%CI 0.7%-1.4%). Table 1 shows the testing and case detection rates by facility type. Of the 34 positive cases, 11 (32%) were asymptomatic. A PCR result was available for 27 Ag-RDT positive participants and 13 Ag-RDT negative participants with SARS-COV-2 symptoms and was positive in 24 (88.9%) and 4 (30.8%) respectively. Circulating variants were identified in 11 participants (Omicron 22A: 36% and 22B: 64%);15 samples could not be sequenced due to CT values >35. Community mobilization was the major cost driver (26%) followed by the purchase of SARS-CoV-2 Ag-RDT (20.5%). The total cost of the intervention was US$50,538;the cost per individual tested was US$15.89 and US$1,484 per new COVID-19. Conclusion(s): Targeted mass community testing using SARS-CoV-2 Ag-RDT is a feasible and affordable strategy in identifying priority areas for vaccination and early treatment for individuals with COVID-19.