The declining number of Covid-19 cases in the local community can be attributed to the mandatory use of masks, coupled with other circuit breaker measures (Reconsider need to wear masks beyond circuit breaker period, by Mr Eric J. Brooks, May 13).

Besides hawkers and food handlers, many workers would find prolonged wearing of masks uncomfortable in our humid environment, such as those working in non-air-conditioned environments like warehouses and construction sites.

They should be encouraged and reminded to replace soiled masks regularly.

The use of masks is also a crucial means of containing the virus spread as it has surfaced that a significant number of infections are asymptomatic.

Together with social distancing and practice of personal hygiene, mask-wearing is a crucial measure in the fight against coronavirus transmission.

Annie Ng Lee Hoon