Sustaining surveillance as an intervention during the COVID-19 pandemic in Cabo Verde and implications for malaria...

Cabo Verde reported the first case of COVID-19 on March 19, 2020. Containment measures were quickly implemented and over 80,000 COVID-19 tests were performed in 2020 with 11,840 confirmed infections (2% of the population) and 154 deaths. In a setting where the last locally acquired malaria case was reported in January 2018, any interruptions to malaria care-seeking have the potential for infections to go untreated and transmission re-establishing. This work aims to determine whether there was any change in the number of people seeking care or being tested for malaria and, using an interrupted time series analysis, identify if any change was associated with implemented COVID-19 measures. Routinely collected surveillance data for outpatient visits, testing for malaria and COVID-19 were aggregated by month for each health facility (outpatient and malaria) or by municipality (COVID-19) from 2017 through 2020. The timeline of COVID-19 measures was generated based on when and where they were implemented. Results show that there was a marked shift in care-seeking in Cabo Verde. Overall, the mean number of observed outpatient visits decreased from 2,057 visits per month during 2017-2019 to 1,088 in 2020, an estimated 28% reduction. However, malaria testing rates per 1,000 outpatient visits after the pandemic began increased by 8% compared to expected trends. Results suggest that the pandemic impacted care-seeking but led to a non-significant increase in testing for malaria per 1,000 outpatient visits. With the cessation of international travel, the risk of imported infections seeding new transmission declined suggesting the risk of undetected transmission was low. It is important for countries to understand their specific malaria risks and vulnerabilities in order to ensure that any progress towards the interruption of malaria transmission can be sustained.