Purpose

This paper presents the latest situation of cholera infection in Hong Kong and the prevention and control measures put into place by the Administration.

Latest Case Number

2. As at 23 March 1998, there were a total of 48 confirmed cholera cases in Hong Kong, comprising 16 local cases, which are found to be infected in Hong Kong, and 32 imported cases.

Follow-up Measures

3. Upon the notification of a cholera case, the Department of Health (DH) and other Government departments concerned will immediately pursue a series of follow-up actions, including the tracing of the source of infection and inspection of the food premises included.

4. Detailed medical, food and travel history of the patients will be gathered. Together with the two Municipal Services Departments, DH will make home visits for disinfection and give chemoprophylaxis to patients�family members. All food premises visited by patients during the incubation period will be inspected and samples collected for examination. For suspected imported cases, people who travel with the patients will be traced to ensure that they have not been infected.

5. In respect of the recent 48 confirmed cases, initial findings of our investigation identify three distinct sources of cholera : -

1. cockles imported from Thailand - responsible for seven cases in early February 1998;
   
   
2. a local licensed Chinese restaurant serving sashimi and hotpot - accounting for three cholera cases and two asymptomatic cholera infections;
   
   
3. four tour groups returning from Thailand in March 1998 - responsible for 29 imported cases.
   
   

The above sources accounted for the majority of the confirmed cholera cases. We have taken a series of measures to control the outbreak at source.

6. Following the discovery of the cholera cases linked to cockles, a hold-and-test procedure (which requires selected imported food to be withheld and tested before release for sale) was introduced to prevent the import of contaminated cockles. A prompt health alert was issued to the public.

7. On the restaurant concerned, the Director of Health served an order on 6 March 1998 ordering the owner to close the premises for disinfection, disinsection and deratting. The owner was instructed to rectify irregularities found during inspection. The order was lifted on 9 March 1998 following satisfactory compliance with the order.

8. In relation to the imported cases, measures were taken to prevent secondary spread of cholera in the territory. Tour members found to have vibrio cholerae in their stools were referred to hospital for necessary treatment. Their homes and toilets used by them were disinfected. Other tour members were traced and given antibiotic treatment. During the period of 15 - 25 March 1998, doctors of the Port Health Service boarded flights from Thailand to advise passengers of the signs and symptoms of illnesses that could be contracted during travel and ways to seek medical attention. Those with symptoms of illnesses were suggested to come forward for appropriate treatment.

9. DH has immediately alerted the Hong Kong Tourist Association, the Travel Industry Council of Hong Kong and the tour companies. Health education to outward travellers has been stepped up via distribution of posters, leaflets and broadcasts at airport and railway stations.

The Interdepartmental Coordinating Committee on the Prevention and Control of Cholera

10. The Interdepartmental Coordinating Committee on the Prevention and Control of Cholera (the Committee), which had held regular meetings in the past to review work progress and control measures against cholera, met on 16 March 1998. Addressing the identified sources of the recent cholera cases, the Committee came up with a four-pronged action plan : -

1. measures for control of imported shellfish
   
   
   • to tighten import control of bivalve shellfish into Hong Kong, particularly from sources where bivalve imports were previously found to be associated with cholera. Bivalves from these sources will be held and tested for cholera before release for sale;
     
     
   • to strengthen the surveillance and sampling of seafood at retail level;
     
     
2. measures to strengthen control at food premises
   
   
   • to step up inspections of all restaurants serving hotpot, seafood and sashimi and testing of fish tank water sample;
     
     
   • to step up inspections of licensed food factories;
     
     
   • to strengthen raids on unlicensed food hawkers;
     
     
   • to intensify checks to ensure that no toilet water is used by seafood hawkers;
     
     
3. measures to promote health education
   
   
   • to organise workshops for travel agencies, seeking their help to remind tour members of the importance of personal, food and environmental hygiene while on overseas trips;
     
     
   • to produce, for presentation to tour groups by travel agencies, a new video on the appropriate health precautions that should be taken during trips;
     
     
   • to design new radio and TV APIs on food hygiene; and
     
     
4. measures to tighten the control of the quality of water for keeping seafood
   
   
   • to set up a working group to look into ways to tighten the control of the quality of water for keeping seafood. This working group will submit recommendations within two months.
     
     

Way Forward

12. The above action plan has been implemented. The Committee has plans to hold further meetings to review the progress and to monitor the situation. The public will be kept informed of the latest development of the issue.



Department of Health
March 1998