Since Sunday, 65 new patients have been diagnosed, including 31 locally transmitted cases in what has been dubbed a "third wave" of the pandemic in the global financial center.
Taxi drivers, restaurant workers, a medical clinic employee and a retirement home resident -- some of the people most vulnerable to the virus and likely to spread it -- have been diagnosed.
"It is possible there could be a major outbreak," Dr. Chuang Shuk-kwan, the head of Hong Kong's Center for Health Protection (CHP) Communicable Disease Branch said Wednesday. "There could be a sudden exponential growth of cases."
Since the virus began spreading worldwide earlier this year, Hong Kong has recorded only 1,324 coronavirus cases and seven virus-related fatalities.
The city's success in containing Covid-19 has been attributed to the government's vigilant enforcement of quarantine for overseas arrivals, efficient contact tracing and residents' willingness to practice good hygiene, wear masks and practice social distancing.
While the new caseload and total number of people diagnosed with Covid-19 is very low compared to countries where the pandemic is running rampant, like the United States and Brazil, experts say the latest rise in cases shows that, despite even the most stringent anti-epidemic controls, the virus still poses a threat.
"This virus will find every chink in your armor," said Dr. Sarah Borwein, a Hong Kong-based physician experienced in infectious diseases and epidemiology. "We've seen that in Beijing, in Singapore, in South Korea and now in Israel, Australia and elsewhere."
Control measures had been working
Before Sunday, Hong Kong had gone three weeks without any instances of people contracting the virus locally, except for some cases directly linked to imported cases, for example, people living in the same house.
Life inside the city had mostly returned to normal, even as the virus ravaged other parts of the world. Bars and restaurants have been open for weeks, albeit at limited capacity, and gatherings of up to 50 people have been permitted since June 19.
Restrictions still apply to inbound travelers. Nearly all new arrivals to the territory are required to undergo a health screening and deep throat saliva test at a government facility at AsiaWorld-Expo, a massive convention center near the airport.
Those who test negative must spend 14 days in quarantine -- either in a government facility or at home with a monitoring wristband -- regularly checking themselves for any sign of the virus and reporting results back to relevant authorities. Positive cases are usually transferred to local hospitals, and their close contacts are sent to isolation centers.
Until this week, health officials had been able to identify and isolate the relatively small number of local cases. However, the recent rise in local transmission has prompted warnings of a community outbreak.
"Since last weekend, the epidemic situation in Hong Kong has changed rapidly, and the situat
