CHP investigates measles infection case epidemiologically linked to earlier cluster
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The case involved a 29-year-old female who is a family member of the two epidemiologically linked measles infection cases announced by the CHP recently. During the contact tracing, the CHP found that the mother of the six-month-old baby boy, who had been infected with measles earlier, developed a sore throat around June 9. She later developed a cough and transient fever. The CHP arranged for her to attend Kwong Wah Hospital for testing. Her blood sample tested positive for antibodies of measles virus upon laboratory testing. She has recovered now.
An epidemiological investigation revealed that the female patient was not certain whether she had ever received measles vaccination. The CHP continues to investigate the cases to identify potential sources of infection and high-risk exposure. Initial investigation revealed that no epidemiological linkages have been established between these three cases and other confirmed cases previously recorded in Hong Kong.
"The incubation period of measles (i.e. the time from infection to onset of illness) is seven to 21 days. Symptoms include fever, skin rash, cough, runny nose and red eyes. When such symptoms appear, 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. Those who suspect they are infected should consult their doctors as soon as possible and inform healthcare workers of their history of exposure to measles," the Controller of the CHP, Dr Edwin Tsui, said.
"Under the Hong Kong Childhood Immunisation Programme, the overall immunisation coverage in Hong Kong has been maintained at a very high level through the immunisation services provided by the DH's Maternal and Child Health Centres and School Immunisation Teams. As evidenced by the findings on vaccination coverage of primary school students and the territory-wide immunisation surveys conducted regularly by the DH, the two-dose measles vaccination coverage has remained consistently high, well above 95 per cent, and the local seroprevalence rates of measles virus antibodies reflect that most people in Hong Kong are immune to measles. However, Hong Kong, as a city with a high volume of international travel, still faces the potential risk of importation of the measles virus and its further spread in the local community. Hence, a small number of people who have not completed a measles vaccination (such as non-local-born people including new immigrants, foreign domestic helpers, overseas employees and people coming to Hong Kong for further studies) are still at risk of being infected and spreading measles to other people who do not have immunity against measles, such as children under 1 year old who have not yet received the first dose of the measles vaccine," he added.
People born before 1967 could be considered to have acquired immunity to measles through natural infection, as measles was endemic in many parts of the world and in Hong Kong at that time. People born in or after 1967 who have not yet completed the two doses of measles vaccination or whose measles vaccination history is unknown, should consult their family doctors as soon as possible to complete the vaccination and ensure adequate protection against measles.
The number of measles cases in some overseas countries remains at a high level this year. 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. 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 measles vaccine or are not sure if they have received a measles vaccine, they should consult a doctor at least two weeks prior to their trip for vaccination.
Besides being vaccinated against measles, members of the public should take the following measures to prevent infection:
- Maintain good personal and environmental hygiene;
- Maintain good indoor ventilation;
- Keep hands clean and wash hands properly;
- Wash hands when they are dirtied by respiratory secretions, such as after sneezing;
- Cover the nose and mouth while sneezing or coughing and dispose of nasal and mouth discharge properly;
- Clean used toys and furniture properly; and
- Persons with measles should be kept out of school till four days from the appearance of a rash to prevent the spread of the infection to non-immune persons in school.
For more information on measles, the public may visit the CHP's measles thematic page. Members of the public who are going to travel can visit the website of the DH's Travel Health Service for news of measles outbreaks outside Hong Kong.
Ends/Friday, June 27, 2025
Issued at HKT 17:30
Issued at HKT 17:30
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