CHP investigates measles infection case epidemiologically linked to earlier case
The Centre for Health Protection (CHP) of the Department of Health (DH) today (June 30) is investigating a case of measles infection and reminded the public that vaccination is the most effective way to prevent measles.
The case involves a five-month-old baby girl who is a family member of a local measles infection case announced by the CHP recently. She developed cough, runny rose, a generalised skin rash and fever on June 27 and was brought to the Accident and Emergency Department of Queen Elizabeth Hospital on June 28. She was admitted for treatment on the same day. Her blood sample tested positive for antibodies of measles virus upon laboratory testing.She remains hospitalised and is in stable condition.
An epidemiological investigation revealed that the baby girl has not yet reached the age to receive the first dose of measles vaccine. She had no travel history during the incubation period. The CHP believes that she acquired the infection from her family member who was recently confirmed to have measles infection. Her remaining five household contacts are currently asymptomatic and put under medical surveillance. Apart from the baby girl's household contacts, no other close contacts were identified. Initial investigation revealed that no epidemiological linkages have been established between these two cases from the same family 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'smeasles thematic page. Members of the public who are going to travel can visit the website of the DH'sTravel Health Servicefor news of measles outbreaks outside Hong Kong.
Update on chikungunya fever
The Centre for Health Protection (CHP) of the Department of Health announced that, as of 5pm today (January 3), no new cases of chikungunya fever (CF) had been recorded.
Latest surveillance data
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Hong Kong has recorded a total of 82 confirmed CF cases last year. Among them, 11 were local cases, and the rest were imported cases.
Since the beginning of 2025, and as of December 10, 2025, a total of 502 264 CF cases and 186 CF-related deaths have been reported in over 40 countries/territories. Cases have been reported in the Americas, Africa, Asia, and Europe. Although the northern hemisphere has entered the winter season, temperatures in subtropical and some temperate regions remain elevated due to climate change, creating favourable conditions for mosquito breeding. In addition, CF outbreaks continue to occur in many countries worldwide. The risk of imported cases persists. Members of the public should check the situation of the destinations before travelling abroad, especially when travelling to Southeast Asian countries.
Government's comprehensive follow-up actions
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Given that some local cases of CF have visited the Tsing Yi Nature Trails or the surrounding area in November last year, the trails are currently closed until further notice. Relevant government departments continue to conduct large-scale mosquito control and prevention efforts along the trails, and the CHP appeals to the public not to enter the area in order to reduce the risk of contracting CF and to avoid exposure to chemicals or interfering with the mosquito control operations. Since the confirmation on December 10, 2025, of a case involving a person who had visited the Tsing Yi Nature Trails on November 30, 2025, no further local cases have been recorded to date. The CHP continues to urge individuals who have recently hiked along the Tsing Yi Nature Trails to seek medical attention as soon as possible if they develop relevant symptoms and to call the enquiry hotline (Tel: 2125 2373), which operates from 9am to 6pm.
The Food and Environmental Hygiene Department (FEHD) has been continuously conducting intensive fogging operations to eliminate adult mosquitoes along the Tsing Yi Nature Trails and the surrounding area. At suitable locations, large ultra-low volume foggers have been deployed, and a robot dog is being put on trial to enhance operational effectiveness. The FEHD has also set up new mosquito trapping devices, cleared discarded containers and garbage that could cause stagnant water, and applied larvicide oil or larvicides in areas with stagnant water that cannot be removed immediately. The FEHD has been collaborating with the Kwai Tsing District Office, the Lands Department and the Drainage Services Department to strengthen efforts in eliminating potential mosquito breeding sites along the Tsing Yi Nature Trails. Pamphlets have been distributed to hikers in the area, urging citizens to be vigilant against mosquito infestations and take personal protective measures. The FEHD has also held meetings of the interdepartmental task forces on anti-mosquito work across districts to discuss the latest developments regarding the situation and plan accordingly to co-ordinate relevant departments and stakeholders in strengthening mosquito prevention and control measures in areas under their purview.
Continuously strengthening prevention and control
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The FEHD and relevant departments have comprehensively enhanced the mosquito control operations in Hong Kong since July last year, and this has continued. Among these, the FEHD has conducted vector investigations and targeted mosquito control operations against the imported and local cases. In light of the local case, the FEHD has immediately conducted follow-up actions, including:
- carrying out intensive fogging in scrubby areas within a 250-metre radius of the relevant locations to kill adult mosquitoes;
- carrying out inspections of the locations, removing stagnant water, applying insecticides and disposing of abandoned water containers every week with a view to preventing mosquito breeding; and
- enhancing public education efforts through organising health talks, setting up mobile education stations, and distributing publicity leaflets.
The abovementioned measures will be continued. Furthermore, the Government will further enhance the mosquito control efforts in addition to the existing measures.
Preventive measures to be taken by the public
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Members of the public should use DEET-containing insect repellents or other effective active ingredients properly to prevent mosquito bites, but the following precautions should be taken when using them:
- read the label instructions carefully first;
- apply right before entering an area with a risk of mosquito bites;
- apply on exposed skin and clothing;
- use DEET of up to 30 per cent for pregnant women and up to 10 per cent for children (for children who travel to countries or areas where mosquito-borne diseases are endemic or epidemic and where exposure is likely, those aged 2 months or above can use DEET-containing insect repellents with a DEET concentration of up to 30 per cent);
- apply sunscreen first, then insect repellent;
- reapply only when needed and follow the instructions; and
- in addition to DEET, there are other insect repellents available on the market containing different active ingredients, such as IR3535 and picaridin. When using any insect repellent, the public should follow the usage instructions and precautions on the product label.
The FEHD also appeals to members of the public to continue to stay alert and work together to carry out mosquito prevention and control measures early, including inspecting their homes and surroundings to remove potential breeding grounds, changing water in vases and scrubbing their inner surfaces, removing water in saucers under potted plants at least once a week, and properly disposing of containers such as empty cans and lunch boxes. The FEHD also advises members of the public and property management agencies to keep drains free of blockage and level all defective ground surfaces to prevent the accumulation of water. They should also scrub all drains and surface sewers with an alkaline detergent at least once a week to remove any mosquito eggs.
The public should call 1823 in case of mosquito problems, and may visit the following pages for more information: the CF page of the CHP and the Travel Health Service, the latest Travel Health News, tips for using insect repellents, and the CHP Facebook Page, Instagram Account and YouTube Channel, and also the Mosquito Prevention and Cntrol dedicated page of the FEHD.
The Centre for Health Protection (CHP), Photo source: reference image
