Applying mathematical modeling to understand the COVID-19 related impact of VMMC service disruption on new infections in Zimbabwe

BACKGROUND: The COVID-19 pandemic has piled unprecedented pressure on health systems in Southern Africa. As a mitigating strategy, countries continue to implement measures to socially distance the population, leading to partial or full suspension of certain services. To de-escalate spread of the pandemic, Government of Zimbabwe continues to strategically prioritize health service delivery to address immediate needs. As a result, Voluntary Medical Male Circumcision (VMMC) services were disrupted in 2020 and this could be prolonged until vaccines are sufficiently scaled up. Given the efficacy of VMMC, we quantified the potential effects of VMMC service disruption on new HIV infections in Zimbabwe.
METHODS: We applied the GOALS model to understand the impact of COVID-19-related disruptions on infections attributable to disruption of VMMC services and potential cost implications. GOALS is an HIV simulation model that estimates number of new HIV infections due to sexual behaviors of population groups. Parameterization of the model is based on national surveys and HIV program data, with model calibration by Avenir Health. We hypothesized three scenarios: Scenario 1: (Pre-COVID trajectory): 80% VMMC coverage by 2030; Scenario 2: (Marginal COVID-19 Impact): 60% VMMC coverage by 2030, and Scenario 3: (Severe COVID-19 Impact): 45% VMMC coverage by 2030. For the period 2030-2050 coverage was maintained across the scenarios, and the time horizon for the model was 36 years beginning in 2014 with discounting at 3%. We also assumed that the fully loaded cost of first-line ART was $165 per person per year and discounted lifetime cost of ART'$3,710.
RESULTS: Relative to Scenario 1, considered the baseline, the disruption of VMMC services in Scenario 2 and 3 will potentially decrease impact of VMMC program on new infections by 7K and 15K over the next 10-30 years, respectively. Thus, the disruptions could yield additional future treatment costs between $27-$55 million for Scenario 2 and 3, respectively.
CONCLUSIONS: Disruption of VMMC services is projected to contribute to 7K-15K additional new infections depending on length and severity of disruption. Unless mitigated, these disruptions could derail the goal of achieving 80% VMMC coverage, and thus it is important to enact policies to sustain VMMC service delivery.