The Centre for Health Protection (CHP) of the Department of Health today (October 4) continued its investigation into the latest situation of invasive Group B Streptococcus infection. While the surveillance data of hospitals in the past two weeks show that the overall daily number of hospitalised patients confirmed to have invasive Group B Streptococcus infection has remained stable, the CHP continued to appeal to members of the public for heightened vigilance and in particular, to pay attention when touching or handling raw freshwater fish. One should wear gloves, as well as not consume undercooked freshwater fish.
The CHP has been closely monitoring the invasive Group B Streptococcus infection cases over the past month and conducted genetic sequencing analysis for patients' specimens to confirm infection number of serotype III sequence type 283 (ST283). The recent surveillance data of hospitals show that the number of hospitalised patients confirmed to have invasive Group B Streptococcus infection has been gradually brought down and has remained stable. For the analysis of the samples of hospitalised patients, since the announcement on September 27, the CHP today confirmed 12 additional ST283 cases involving patients previously admitted to the hospitals. The patients involved five males and seven females, aged between 49 and 97. The patients mainly presented with sepsis and joint abscess. Together with the 79 cases of ST283 infection announced earlier, this cluster involved a cumulative total of 91 patients residing in 18 districts throughout the territory. The onset date of the disease for all 91 patients was before mid-September; 70 of them have underlying illnesses, 40 have been discharged, 43 hospitalised patients are in stable condition, four are in serious condition and the other four with underlying illnesses have passed away.
The CHP's epidemiological investigations revealed that 75 patients have had contact with or handled raw freshwater fish before the onset of symptoms (seven of them reported that they had wounds on their hands when handling raw freshwater fish). Twelve patients cannot rule out that they have consumed undercooked freshwater fish (not freshwater fish sashimi), and the exposure history of the remaining four patients is under investigation.
While none of the 91 patients were fishmongers or engaged in fish culture-related jobs, two of them are cooks who have handled raw freshwater fish. The patients resided in various districts throughout the territory, and the freshwater fishes concerned were bought from 47 markets in 18 districts respectively. The CHP has completed the testing and analysis on all freshwater fish and environmental samples. Apart from five freshwater fish and environmental samples collected from a retail fish stall in Shek Wu Hui Market which tested positive for ST283 announced earlier, 68 freshwater fish and environmental samples collected respectively from the Freshwater Fish Market under the Cheung Sha Wan Wholesale Food Market, Yeung Uk Road Market, Pei Ho Street Market and three local fish ponds in Yuen Long all tested negative for ST283.
"Members of the public should wear gloves when touching or handling raw freshwater fish. If symptoms such as an inflamed wound and fever develop, they should seek medical attention promptly. Meanwhile, the public should refrain from consuming undercooked freshwater fish," a spokesman for the CHP reminded.
To prevent Group B Streptococcus (ST283) 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:
- To minimise infection risks, workers of aquatic products or restaurants must wear gloves when handling aquatic products and avoid direct contact with aquatic products or dirty water with bare hands;
- When buying aquatic products, the public must avoid direct contact with aquatic products or use any towel provided by the stalls. They should wash hands with liquid soap and water as soon as possible if they have had contact with aquatic products which are not fully cooked. When handling aquatic products at home, the public should also wear gloves and wash hands thoroughly afterwards;
- Members of the public must not eat any freshwater fish sashimi, raw or undercooked freshwater aquatic products. When consuming hot pot food or congee items which consist of aquatic products, they should ensure that the food is thoroughly cooked in which the centre of the food should reach a temperature of at least 75 degrees Celsius so as to destroy pathogens; and
- People must not touch aquatic products directly whenever there is a wound on their hands. If a wound is sustained during handling aquatic products, the wound must be cleaned immediately and properly covered with a waterproof adhesive dressing. Individuals should seek medical advice promptly when a wound infection is found.
The public may visit the CHP's Invasive Group B Streptococcus Infection associated with Sequence Type 283 (ST283) page for more information.
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