COVID-19 test positivity rate dynamics in West Sumatra, Indonesia: a retrospective study

Abstract

Background: COVID-19 test positivity rate (TPR) is essential to estimate and control SARS-CoV-2 transmission in a population at a specific time, yet the TPR trends at a provincial level in Indonesia are unclear. This study aimed to determine the COVID-19 TPR dynamics of the Indonesian West Sumatra province in the first year of documented cases.Methods: We conducted a retrospective study using secondary data of the COVID-19 quantitative reverse transcription-polymerase chain reaction (q-RT-PCR) test in West Sumatra Province from April 2020 to March 2021. To examine trends, we estimated TPR(s) on an annual, quarterly, and monthly basis in the province, its regions (cities/ regencies), and districts.Results: From a total of 410,424 individuals taking the COVID-19 q-RT-PCR examination during one year, the provincial TPR was 8.11%. The third quarter (October 2020 – December 2020, 12.18%) and October 2020 (15.62%) had the highest TPR quarterly and monthly, respectively. The TPR of cities was almost certainly twice that of regencies. Annual TPR varied significantly (p<0.001) across regions, districts, and periods.Conclusion: The COVID-19 TPR trends in West Sumatra at the first year of the pandemic were generally higher than the global recommendation. Further study on population density, public mobility, and implementation of health protocol in the province should be valuable to understand TPR dynamics.