Micro-costing analysis of integrating SARS-CoV-2 antigen rapid detection tests into routine health facility services: a comparison of test-all versus screen-and-test models in Cameroon and Kenya.

Introduction: Understanding costs associated with identification of emerging infections is critical to inform the policy. Nested within a randomised controlled trial that found that a test-all (TA) model for rapid SARS-CoV-2 testing identified more SARS-CoV-2 cases than the standard screen-and-test (ST) model. Our study assessed the cost-effectiveness of integrating SARS-CoV-2 services into maternal, neonatal and child health (MNCH), HIV and tuberculosis (TB) clinics using the two models in Cameroon and Kenya. Methods: The total costs of implementing the TA and ST models in Cameroon and Kenya were estimated from a health systems perspective using a micro-costing method. The cost per client tested (CPCT) and tested positive (CPCTP) for SARS-CoV-2 were estimated by dividing the total cost of each model by the number of clients tested and tested positive, respectively. A decision tree and cost-effectiveness acceptability curve were used to compare the cost-effectiveness of the two models. Results: In Cameroon, the total cost of the TA model was US$141,942, while the ST model was US$48,020. In the TA model, the CPCT was US$7.66 and the CPCTP was US$508.75, whereas in the ST model, they were US$25.02 and US$727.58, respectively. In the TA model, the biggest cost was SARS-CoV-2 antigen rapid detection tests (Ag-RDTs) at 61% (US$86,853), whereas in the ST model, it was personnel at 39% (US$18,592). In Kenya, the total cost was US$39,264 in the TA model and US$27,500 in the ST model. The TA CPCT was US$13.04 and the CPCTP was US$1,189.81, whereas in the ST model the costs were $125.00 and $1,250.01 respectively. In both models in Kenya, the biggest expenditure was personnel, at 45% ($17,696) of cost in TA and 56% ($15,267) in ST. In both countries, the TA model was more cost-effective. Conclusions: Implementation of the TA model is a more cost-effective approach to increase early identification of individuals with SARS-CoV-2 infection.