A universal Covid-19 test has always been a high-stakes affair. From taking specimens to the time required, any logistical missteps will undermine the scheme seeking to identify “silent transmitters” in society. Equally pivotal are public participation and follow-up procedures for those infected and their contacts. All this will be put to the test when the much-touted exercise is finally ready to begin on September 1. As acknowledged by Chief Executive Carrie Lam Cheng Yuet-ngor during a review of the city’s preparedness yesterday, the long-awaited community screening is apparently just an extra step worth taking following a boost in testing capacity with the help of Beijing. She conceded that criticism concerning cost-effectiveness was not unfounded, but remained adamant the epidemic would be further eased when hidden transmissions were curbed. Whether the voluntary scheme will make a difference to the current situation remains to be seen. With daily infections continuing to ease, arguably there is less urgency for the test. Indeed, its purpose remains a matter of debate among health experts, with some questioning whether it is worth the money, time and effort. Based on the results of targeted testings, there could be 1,500 asymptomatic carriers in society, but the underwhelming response of some high-risk groups tested by the government earlier, such as domestic helpers staying in dormitories, do not bode well for a citywide exercise. With millions of people still able to freely move around during the two-week test period, critics say the exercise is meaningless. Follow-up action will also be difficult and there needs to be effective tracing and sufficient health care facilities for those who are found to be infected and their close contacts. The additional hospital beds, isolation facilities and cross-border travel arrangements announced by the chief executive may give the impression that the city is better prepared than it was eight months ago. But Lam did not deny there were inadequacies. The number of cases over the coming week will further indicate whether the epidemic is continuing to ease, and keeping figures down will be a bigger test for both the people and the government.