CHP updates on latest situation of invasive Group B Streptococcus infection
The Centre for Health Protection (CHP) of the Department of Health today (September 16) continued its investigation into the latest situation of invasive Group B Streptococcus infection. The CHP appealed to members of the public for heightened vigilance and in particular, to pay attention when touching or handling raw freshwater fish and should wear gloves, as well as not to consume undercooked freshwater fish.
The CHP has been monitoring with the Hospital Authority (HA) the admission figures in relation to invasive Group B Streptococcus infection cases. Since the announcement of the situation of Group B Streptococcus infection belonged to serotype III sequence type 283 (ST283) on September 13, the CHP has today confirmed 13 additional ST283 cases involving patients recently admitted with invasive Group B Streptococcus infection. The CHP's epidemiological investigations showed that the 13 patients with ST283 infections involved seven males and six females, aged between 35 and 94. The patients mainly presented with sepsis (eight patients) and joint abscess (five patients). Together with the 27 cases of ST283 infection announced on September 13, this cluster involved a cumulative total of 40 patients residing in 18 districts throughout the territory. Their onset date of the disease were between August 8 and September 5, and 30 of them have underlying illnesses. The HA's information showed that among the 40 patients, 10 have been discharged, 25 hospitalised patients are in stable condition, three in serious condition and the other two with underlying illness passed away.
The CHP's analysis of samples of other recently admitted patients is still in progress and it cannot rule out that the number of cases will further increase.
　
The CHP's epidemiological investigations revealed that 31 patients have contacted with or handled raw freshwater fish before onset of symptoms (five of them reported that they had wounds on their hands when handling raw freshwater fish), six patients cannot rule out that they have consumed undercooked freshwater fish (not freshwater fish sashimi), and the exposure history of the remaining three patients is under investigation.
Furthermore, none of the 40 patients were fishmongers or engaged in fish culture related jobs. As the patients resided in various districts throughout the territory, and the freshwater fishes concerned were bought from 23 markets in 11 districts respectively, the CHP considered that the affected freshwater fish may involve the wholesale level. After knowing that the genetic sequence of samples collected from a retail freshwater fish stall matched those found in some patients, the CHP immediately teamed up with the Agriculture, Fisheries and Conservation Department (AFCD) to conduct an inspection in the Freshwater Fish Market under the Cheung Sha Wan Wholesale Food Market, and collect environmental samples for testing and analysis. The laboratory analysis is still in progress. So far, no abnormality has been observed regarding the freshwater fish in the wholesale fish markets. Besides, the CHP and the Food and Environmental Hygiene Department (FEHD) have conducted medical surveillance on over 200 workers and no symptomatic worker identified. The FEHD have strengthened the cleansing and disinfection of the relevant markets.
The CHP has issued a letter to doctors to enhance their alertness for Group B Streptococcus infection cases. The CHP's investigations, as well as prevention and control works, which include closely monitoring the admission cases, conducting genetic analysis of patients' bacterial samples, testing environmental samples, and strengthening health education to workers and the public, especially the education related to wound care and consumption of freshwater fish, are still ongoing. The AFCD will continue to monitor the health condition of freshwater fish supplied to Hong Kong and ensure that there are no abnormalities and to implement feasible measures to reduce proliferation of bacteria.
"Members of the public shall wear gloves when touching or handling raw freshwater fish. If symptoms such as 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 the 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 the aquatic products or use any towel provided by the stalls. They should wash hands with liquid soap and water as soon as possible if having 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 pathogen; and
- People must not touch aquatic products directly whenever there is a wound on hands. If a wound is sustained during handling aquatic products, the wound must be cleaned immediately and properly covered with waterproof adhesive dressings. Individuals should seek medical advice promptly when 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.