Advisory Council on Food and Environmental Hygiene

Pro-active Actions taken by
the Multi-disciplinary Response Team 
To Contain the Spread of SARS Cases

PURPOSE 

This paper informs members of how the environmental investigations of SARS cases are conducted and the outcome of such investigations. Members are requested to note the contents of this paper.

BACKGROUND

2. The unusually large number of SARS cases in Block E of Amoy Garden led us to suspect that, apart from person-to-person contact, environmental factors were also at play in the spread of the disease there. Investigations into various areas, including the drainage and sewerage systems, water supplies, vectors, garbage, elevators and the construction site nearby were conducted. The findings of our investigations had been published and were conveyed to Members vide ACFEH Paper 5/2003. 

3. The Amoy Garden��s experience reveals that environmental factors conducive to the spread of the virus may exist in buildings and have to be tackled early in order to contain the spread of the disease. We are also aware that we need experts from various fields to participate in our investigations in order to identify possible channels of spread. We therefore established a Multi-disciplinary Response Team (��the Team��) in mid April to proactively conduct environmental investigations where SARS cases appear to be spatially and temporally related and to take remedial action. 

MODE OF OPERATION �V IDENTIFICATION OF TARGET BUILDINGS

4. All buildings where one or more residents have been confirmed to have contracted SARS, or where two or more residents have been suspected to have contracted SARS or have been admitted to hospital for observation within a period of 10 days are the targets of the Team��s investigations. In some cases, although the cases occurred within a span of more than 10 days, the Team also conducts investigations on exceptional grounds, e.g. in Wing Shui House in Lek Yuen Estate where residents in two units in the same vertical stack on two consecutive floors contracted the disease. Housing estates where there is frequent occurrence of SARS cases within a short period of time will also become our target of investigation, even though there may only be one case in each individual block of building. These buildings/housing estates are identified by a computer system developed by the Police to assist in criminal investigations. Staff from Police and Department of Health work round-the-clock to produce daily reports of target buildings every morning to maximize the time available for the Team to act. 

MODE OF OPERATION �V INITIAL INVESTIGATIONS

5. On receipt of the daily list of target buildings/housing estates, the relevant Regional Office of the Department of Health will conduct an initial assessment as to whether environmental investigations should be conducted. Examples of cases which do not warrant further investigation are those patients who are health care workers who might have been infected in hospitals, or those patients who belong to the same household.

MODE OF OPERATION �V FURTHER INVESTIGATIONS

6. For those cases which require further investigations, the Team will promptly move into action. The areas that the Team covers and the division of responsibility amongst Team members are as follows �V

General cleanliness

 

Food and Environmental Hygiene Department (together with Housing Department in the case of public housing estates)

Garbage collection

Food and Environmental Hygiene Department (together with Housing Department in the case of public housing estates)

Pest infestation

Food and Environmental Hygiene Department (together with Housing Department in the case of public housing estates)

Drainage and sewerage system of public housing estates

Housing Department

Drainage and sewage system of private residential buildings

Buildings Department

Lighting and ventilation system

Electrical and Mechanical Services Department

Air pathways of transmission in and out of household units

Environmental Protection Department

Collection of various types of environmental swabs

Food and Environmental Hygiene Department on the advice of Department of Health

Public sewerage system

Drainage Services Department

Hitherto, the Team has conducted investigations into 5 buildings/housing estates, viz. namely Tung Tau Estate of Kwun Tong, Lek Yuen Estate of Sha Tin, Lai King and Kwai Chung Estates of Kwai Tsing, and Kin Sang Estate of Tuen Mun. 

MODE OF OPERATION �V REMEDIAL ACTION

7. The Team will take prompt action to remedy any irregularities identified in the course of investigation, without waiting for a determination as to whether these irregularities contributed to the spread of the disease. This is because laboratory analysis often takes time and it may be too late to act only when all testing results are available. Moreover, a high standard of environmental hygiene and building maintenance are important for public health reasons regardless of whether there is any SARS case. Examples of the remedial actions taken are pest disinfestation measures, requiring the building management to cleanse common parts of a building where general cleanliness is not satisfactory and requiring the relevant owners to effect repairs to parts of the building where structural defects are found. 

8. In addition, FEHD offers to every household with confirmed SARS patients hygiene advice and demonstration of disinfection. More than 70% of these households accept the demonstration service. Those who decline the offer do so mainly on the grounds that they have already disinfected their own flats at the first instance. 

MODE OF OPERATION �V REMEDIAL ACTION FOR DISTRICTS WITH LARGE NUMBER OF SARS CASES

9. For districts with large number of SARS cases, the Team takes actions on various fronts to eliminate possible channels in the environment for the disease to spread, regardless of whether the spread was initially caused by environmental factors. For example, although about 84% of the SARS cases in Tai Po were connected with hospital infection, the Team took the following actions to prevent further spread of the disease �V

        Urge public transport operators to disinfect their vehicles frequently, especially those deployed on routes covering hospitals

Transport Department

              Conduct hygiene inspection and pest disinfestations to each of the 1,181 floors of 41 blocks in 6 public housing estates in Tai Po (i.e. Tai Yuen, Kwong Fuk, Fu Shin, Fu Heng, Tai Wo and Wan Tau Tong Estates) where higher number of SARS cases are identified

Food and Environmental
Hygiene Department

       Step up cleansing and disinfection of all public housing estates in Tai Po, including application of disinfectant agent to flushing water tanks

        Inspect, disinfect and cleanse drainage systems and underground sewers in the 6 public housing estates where higher number of SARS cases are identified.

            Continue to follow up the disinfestations work in public housing estates as advised by Food and Environmental Hygiene Department

              Distribute health and hygiene guidelines to all estate tenants

Housing Department

             Inspect and investigate the drainage system of the affected private buildings in Tai Po

            Arrange seminars for the public and building management companies on the proper

Buildings Department

              Cleanse public sewers in the vicinity of the affected buildings in Tai Po

Drainage Services Department

CONCLUSION

10. The Team has hitherto not found cases similar to Amoy Garden Block E whereby it was highly probable that environmental factors played a part in the spread of the disease. Nevertheless, the investigative and remedial actions taken by the Team have effectively removed potential channels for further spread of the disease and have brought about greater awareness of the importance of a high standard of environmental hygiene and proper building maintenance. This has not only contributed to the overall control of the spread of SARS in Hong Kong, but is also useful in prevention of the disease in the longer term. 




Health, Welfare and Food Bureau
May 2003



 

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