An Empirical Argument for Mass Testing: Crude Estimates of Unreported COVID19 Cases in the Philippines vis-Ã -vis Others in the ASEAN-5

Introduction. International media has considered the Philippines as the country with the longest and strictest quarantine measures in the world. At the same time, the government has not pursued aggressive mass testing due to perceived resource constraints. This study presents an empirical support for a mass testing policy. Method. Crude estimates for “true†COVID19 prevalence are made using adjusted case fatality ratios and reported COVID19 cases for the Philippines, Indonesia, Malaysia, and Thailand. Singapore figures are utilized as baseline in the computations because of the island-nation's widespread testing strategy. Results. The analysis reveals that 96-99% of COVID19 cases in the ASEAN-5 were undetected during April-June 2020. Roughly three million Filipinos (2.6% of the national population) may have been infected by the virus in the same period—the worst record in the ASEAN-5 group in percentage terms. Discussion. The findings reinforce the WHO recommendation of “test, trace, and isolate.†Broad-base testing is urgently needed to reduce the magnitude of undetected COVID19 cases. The Philippine government must devote necessary resources to do this; the economic and social costs of not doing so are greater.