Travellers returning from tsunami-hit areas should be alert for any symptoms of infectious disease, including fever, diarrhoea and rash, the Department of Health says, adding they should seek medical advice if they feel unwell.

The department said the sources of water and food in the affected areas might have been contaminated and could lead to food poisoning as well as food and water-borne diseases, such as bacillary dysentery and cholera.

Many of the affected areas are also endemic to mosquito-borne diseases such as malaria and dengue fever, the department added.

Arrangements have been made with airline companies to broadcast health messages on flights from places affected by the tsunamis, advising passengers to approach the airport medical post on arrival for assistance if they do not feel well.

The Centre for Health Protection has also sent letters to all doctors urging them to be on the alert when attending patients with a history of travel to the affected areas and to look out for symptoms of infectious disease.

Employers of domestic helpers are advised to keep an eye on the health of their helpers on their return to Hong Kong and arrange for their helpers to seek medical advice if in doubt.

Members of the public should be vigilant at all times in personal, food and environmental hygiene for the protection of their own health and prevention of infectious diseases.