Former Thai WHO chief calls for new virus testing strategy


BANGKOK • Thailand faces a call for a different testing approach to help guide decisions about reopening its economy following a drop in daily coronavirus infections.

The nation has conducted more than 100,000 tests and ramped up daily testing capacity to about 20,000, focused on those with suspect symptoms or contact with infected people. This approach is good for clinical purposes, but less so for population surveillance, according to William Aldis, formerly the World Health Organisation’s (WHO) representative in Thailand.

The country needs to pick representative groups, ideally province-by-province, and test them recurringly to get a sense of the incidence of the virus within the population over time, said Aldis. This is a “paradigm shift” to so-called sentinel surveillance from the current approach of “more or less what we call opportunistic sampling,” he added.

“You need systematic collection of data,” said Aldis, now an adjunct assistant professor at Thammasat University’s Faculty of Public Health in Thailand. “You get a better decision if you’re taking this approach. It certainly gives it a level of validity we don’t have now.”

Countries around the world are trying to improve testing to track the disease. While Thailand plans to do some sentinel surveillance of patients with influenza-like illnesses, testing remains focused on those at high risk of novel coronavirus infection, according to Tanarak Plipat, deputy head of the disease control department.

Confirmed daily new cases have declined during a state of emergency and partial lockdown that’s due to expire at the end of April. Officials are working on a plan for restarting the economy — which is headed for a deep contraction — while stressing such moves would be gradual and preserve social distancing.

Thailand reported 32 new coronavirus cases on Sunday, taking the total to 2,765. The rate of new cases has declined from more than 100 each day in late March and early April.

The Thai government is due to meet this week to deliberate relaxing of measures and state-of-emergency rules that have been in place since late March.