With the approach of the Easter holidays, the Controller of the Centre for Health Protection (CHP) of the Department of Health, Dr Edwin Tsui, today (April 16) appealed to members of the public who intend to travel to stay alert to the situation of infectious diseases at their destinations and to prevent various infectious diseases, in particular measles, dengue fever (DF) and norovirus infection.
 
Measles
 
     Recently, the number of measles cases in some overseas countries has been increasing. The outbreaks in North America (including the United States and Canada), Europe and neighbouring areas (including Vietnam, Cambodia and the Philippines) are ongoing due to the relatively low vaccination rate. Furthermore, an increasing number of measles cases have also been recorded in Japan and Australia this year. Overseas cases mainly affected people who were unvaccinated or had unknown vaccination status. This shows the importance of maintaining a high vaccination rate and herd immunity within the community.
      
     Vaccination is the safest and most effective preventive measure against measles. For those who plan to travel to measles-endemic areas, they should check their vaccination records and medical history as early as possible. If they have not been diagnosed with measles through laboratory tests and have never received two doses of the measles vaccine or are not sure if they have received the measles vaccine, they should consult a doctor at least two weeks prior to their trip for vaccination. Healthy people in general can enjoy long-term, even lifelong protection after receiving the measles vaccination as recommended. Two doses of the measles-containing vaccine can confer protection of up to 97 per cent.
      
     The incubation period of measles is seven to 21 days. Symptoms include fever, skin rash, cough, runny nose and red eyes. If such symptoms appear after returning from measles-endemic areas, people should wear surgical masks, stay home from work or school, avoid crowded places and contact with unvaccinated people, especially those with weak immune systems, pregnant women and children under 1 year old, and should consult their doctors as soon as possible.
 
Dengue fever

     During their travels, members of the public are urged to stay vigilant against mosquito-borne diseases, including DF, Japanese encephalitis, zika virus infection, and malaria, with DF being a particular concern, and to carry out stringent anti-mosquito measures. In 2024, the World Health Organization recorded over 14 million cases of DF, which was a record number of cases. Some popular travel destinations for Hong Kong citizens, such as Thailand, Singapore and Malaysia, are also endemic areas for DF.
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     Members of the public should follow these anti-mosquito measures when travelling to areas affected by DF to reduce the chance of acquiring mosquito-borne diseases during travels and spreading the diseases to others through mosquitoes:
 

• Wear loose, light-coloured, long-sleeved tops and trousers;
• Use DEET-containing insect repellent on exposed parts of the body and clothing. For details about the use of insect repellents and key points to be observed, please refer to Tips for using insect repellents;
• When engaging in outdoor activities, avoid using fragrant cosmetics or skincare products, reapply insect repellents according to instructions, and apply insect repellents after sunscreen if both are used; and
• Apply insect repellent for 14 days upon returning to Hong Kong from areas affected by DF.

 
Norovirus infection
 
     Norovirus is more active in winter, and the virus can be transmitted through various means, such as eating contaminated food, contacting with the vomit or excreta of infected persons, and touching contaminated objects. It may lead to an outbreak of acute gastroenteritis (AGE). With the current AGE activities in popular travel destinations for Hong Kong citizens, such as Japan, Singapore and Taiwan, being higher than during the same period last year, and with temperatures in some areas remaining low, members of the public are still at risk of infection during travels.
      
     Norovirus is also a common cause of food poisoning and is often related to consumption of undercooked or raw shellfish. Therefore, the following points on food safety should be observed during travels:
 

• Patronise reliable and licensed restaurants;
• Avoid raw food or undercooked food, especially raw seafood or meat;
• Be careful in choosing cold cuts, including sashimi, sushi and oysters in buffets;
• When having hotpots or barbecuing, make sure the food is thoroughly cooked before eating;
• Drink boiled water; and
• Wash hands thoroughly with liquid soap and water before eating and after using the toilet.

 
     Dr Tsui reminded returned travellers to consult a doctor promptly if they develop symptoms such as fever, respiratory symptoms, rash or gastroenteritis symptoms, and to inform the doctor of their travel history for prompt diagnosis and treatment.
      
     "The CHP will continue to monitor the situation of infectious diseases locally and abroad and provide timely updates to members of the public to keep them informed about the development of infectious diseases and help them prepare for precautionary measures," Dr Tsui said. 
      
     The public may visit the DH's Travel Health Service webpage for the latest information on infectious disease outbreaks in various parts of the world and the preventive measures.

Ends/Wednesday, April 16, 2025
Issued at HKT 11:40

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