Coronavirus: Hong Kong health adviser warns of possible fifth wave of infections after discovery of untraceable case with mutant strain

A top Hong Kong public health adviser has warned a potential fifth wave of Covid-19 infections could emerge in the next two weeks, hours after authorities identified the city’s first untraceable case with a mutant strain and evacuated hundreds from a residential block overnight.

Chinese University respiratory medicine expert Professor David Hui Shu-cheong also said the government might need to look into tightening social-distancing measures once more if local coronavirus infections rose rapidly, particularly if unlinked cases made up more than 20 per cent of the total.