Health authorities said on Saturday that 58 people are currently being treated for malaria at hospitals here and that they will focus on testing arrivals from Guinea for the mosquito-borne disease.
One patient is critically ill in intensive care, while two others are in serious condition. Two people have already died.
Officials said they had recently screened more arrivals from the west African country, including around 120 passengers who flew in on Friday and some 90 others staying at quarantine hotels. More than 30 have tested positive, or preliminary positive, for malaria.
Chuang Shuk-kwan from the Centre for Health Protection said she understood that around 200 more people are set to arrive in Hong Kong from Guinea, adding that she has not heard of any plans to ban flights from there.
She also said officials would focus on testing travellers from Guinea, where the bulk of Hong Kong's imported malaria cases were found.
However, she assured the public that the disease was unlikely to spread in Hong Kong's urban areas.
"In Hong Kong, malaria is not transmitted through air or the respiratory tracts. The disease is transmitted through a vector, that is mosquitoes. There are no mosquitoes in urban areas of Hong Kong that would transmit malaria, so the risk of transmission in the community is very low," Chuang said.
Despite that, a chief manager of the Hospital Authority (HA), Lau Ka-hin, said healthcare workers were on high alert.
"We have raised our mosquito alert index to the highest level. We would apply larvicidal oil and other chemicals, since there are other mosquito-borne diseases, such as dengue fever," Lau said.
"In the summer, especially the rainy season, various HA organisations would reinforce mosquito control."
Separately, health authorities reported 4,602 new Covid cases, of which 280 were imported.
More than 1,460 people are currently being treated at public hospitals, seven of whom are in intensive care.
Four more people with Covid, aged between 72 and 93, have died.
General Covid-19 situation: https://www.coronavirus.gov.hk/eng/
Covid-19 testing: https://www.communitytest.gov.hk/en/
Community testing notices: https://bit.ly/3ivX2Ce
Community Clinics for Covid-19 patients: https://bit.ly/3l5CkKv
RAT reporting platform: https://www.chp.gov.hk/ratp/
Vaccination programme: https://www.covidvaccine.gov.hk/sen/
Vaccination pass scheme: https://www.coronavirus.gov.hk/eng/vaccine-pass.html
Hotline for Covid-positive patients: 1836 115