CHP provides update on investigation into invasive Group B Streptococcus cases

     The Centre for Health Protection (CHP) of the Department of Health (DH) today (October 18) said that it is following up on the epidemiological investigation into the surge in invasive Group B Streptococcus cases, and appealed to members of the public again for maintaining personal, food and environmental hygiene to prevent infection.
 
     The CHP has received reports by the Hospital Authority that 58 and 21 in-patients had tested positive for invasive Group B Streptococcus last month and in October (as of October 10) respectively, showing a surge as compared with a range of nine to 26 cases per month over the past three years (2019 to August 2021). The 79 cases involve 42 males and 37 females aged from one month to 96 years. They mainly presented with septicaemia, meningitis, pyogenic arthritis or abscess/cellulitis.
 
     Investigations show that some of the patients have history of handling freshwater fish, including grass carp, before onset. Some of them had reported handling of raw freshwater fish with hand wounds.
 
     Laboratory analysis has shown that at least 32 cases belonged to serotype III sequence type 283 (ST283) which was of identical genetic sequencing to the fish and environmental samples taken in markets visited by some of the cases. The CHP considers that handling raw freshwater fish with hand wounds or consumption of undercooked freshwater fish may be associated with the infection. In fact, association between consumption of raw freshwater fish and invasive Group B Streptococcus of ST283 has been reported previously in overseas literature. Presence of Group B Streptococcus of ST283 was also reported in freshwater fish in southeast Asia countries.
 
     The CHP will issue a letter to doctors to enhance their alertness of Group B Streptococcus infection.
 
     "We have also alerted the Food and Environmental Hygiene Department (FEHD) and the Agriculture, Fisheries and Conservation Department (AFCD) of the incident. The FEHD has been carrying out thorough cleansing and disinfection of the market concerned, whereas the AFCD will assist in taking more fish samples from the freshwater fish wholesale markets in order to ascertain the local situation," a spokesman for the CHP said. 
 
     A spokesman for the FEHD said that raw freshwater fish is a prohibited food item under the Food Business Regulation (Cap. 132X). The FEHD has made public education efforts to warn the public against eating raw freshwater fish and issued an advisory letter to fish stalls in the FEHD's markets or holding fresh provision shop licences on handling fish with care, especially by observing personal, food and environmental hygiene. 
 
     To prevent Group B Streptococcus infection, members of the public are reminded to maintain personal, food and environmental hygiene and should keep their hands clean and practice good wound care at all times, especially:
•Wear gloves while handling raw freshwater fish or seafood and avoid having wounds coming in contact with raw freshwater fish or seafood;
•Avoid eating raw freshwater fish or seafood; and
•Avoid skin contact with dirty water when visiting a wet market and maintain good hand hygiene.