Source: Hong Kong Government special administrative region
The Centre for Health Protection (CHP) of the Department of Health (DH) today (August 25) issued a letter to all schools through the Education Bureau, and urged them to take active measures on their campuses to prevent the spread of communicable diseases, particularly mosquito-borne diseases, in order to safeguard students’ health.
“As many students will be back to school next week, the CHP sent a letter to primary and secondary schools, kindergartens and childcare centres in Hong Kong to remind them of the risk of mosquito-borne diseases, such as chikungunya fever (CF) and dengue fever (DF), in Hong Kong. In addition to these mosquito-borne diseases, local seasonal influenza, respiratory syncytial virus (RSV) and hand, foot and mouth disease (HFMD) have shown an upward trend in activity levels over the past one to two months. Schools should stay alert, and regularly clean and disinfect to lower the risk of transmitting communicable diseases in school,” the Controller of the CHP, Dr Edwin Tsui, said.
He also appealed to students and school staff to promptly seek medical advice if they develop symptoms such as fever, respiratory symptoms, diarrhoea, vomiting or skin rashes. They should not return to campus for lessons or work.
The following are the current activity levels of mosquito-borne diseases, respiratory diseases and HFMD in Hong Kong, along with preventive measures.
A. CF and DF
CF is a mosquito-borne viral disease caused by the chikungunya virus. It is characterised by fever and debilitating joint pain. Other common signs and symptoms include rash, muscle pain, headache, nausea and fatigue. Symptoms usually last for a few days. While most patients recover fully, joint pain may persist for several months in some cases. Severe symptoms and deaths from CF are rare. However, high-risk groups, including young children (particularly those under one-year-old), are more likely to develop complications after infection. As of today, the CHP recorded nine CF cases this year. All were imported cases.
DF is an acute febrile viral illness with symptoms such as high fever, severe headache, pain behind the eyes, rash, muscle and joint pain. The symptoms of the first infection are usually mild, but subsequent infections with dengue virus of other serotypes are more likely to result in severe dengue, which may progress to circulatory failure, shock and even death. As of August 21, the CHP recorded 41 DF cases this year. All were imported cases.
These mosquito-borne diseases are not transmitted from person to person. However, schools should take measures to strengthen efforts to prevent water accumulation and eliminate potential breeding grounds of mosquitoes, such as changing water for plants at least once a week, covering all water containers tightly and keeping all drains free from blockage. School management is advised to appoint designated staff to be responsible for mosquito prevention and control on campus. Details are available from the guidelines published by the Food and Environmental Hygiene Department.
B. Respiratory infections
The CHP’s latest surveillance data showed that local seasonal influenza activity has increased slightly since mid-July. For other respiratory pathogens, the activity of RSV has been gradually increasing since June, and it is expected to remain active for some time. Overall, rhinovirus/enterovirus and RSV have relatively higher activity levels among respiratory pathogens detected in paediatric respiratory specimens received by the Hospital Authority. According to previous surveillance data, after the start of the new school year, the weather will get cooler, and it may lead to more outbreaks of respiratory tract infections in schools. Additionally, the activities of both COVID-19 and seasonal influenza may increase at the end of this year or early next year.
Vaccination is the first line of defence against seasonal influenza, reducing the chance of serious complications or death after infection. Parents are advised to arrange for their children to participate in the seasonal influenza vaccination (SIV) outreach activities at school or to visit their family doctor for the SIV at the start of the new school year to enhance personal protection. Studies have shown that children who receive the SIV are likely to reduce school absenteeism. Parents should note that it takes about two weeks after vaccination for the body to develop sufficient antibodies to protect against influenza infection. Therefore, vaccination should be completed well in advance of the onset of winter. The DH has earlier sent a letter to all schools in Hong Kong informing them of the arrangements for the 2025/26 SIV School Outreach Programme. The majority of schools have responded positively. Based on local experience, school participation in the outreach vaccination programme can double children’s influenza vaccination rates, effectively strengthening the immunity barrier of schoolchildren. Schools that have yet to join the programmes should enrol as soon as possible.
In addition, to prevent respiratory diseases, members of the public should maintain good personal, hand and environmental hygiene. Students/staff members with respiratory symptoms, even if the symptoms are mild, should wear a surgical mask, refrain from going to work or attending classes, avoid crowded places and seek medical advice promptly. They should maintain hand hygiene before putting on and after removing a mask.
C. HFMD
HFMD is a common disease in children usually caused by enteroviruses such as coxsackie viruses and enterovirus 71 (EV71). In Hong Kong, the peak season for HFMD and EV71 is usually from May to July, with a smaller peak occurring from October to December after the start of the school year. This year, an upward trend in certain indicators monitoring HFMD activity was observed between June and August. As of August 21, the CHP recorded 79 HFMD outbreaks in schools this year.
HFMD is mainly transmitted by contact with an infected person’s nose or throat discharges, saliva, fluid from vesicles or stool, or after touching contaminated objects. To prevent the spread of HFMD within school settings, affected children should remain at home and refrain from attending school until they have completely recovered.
Schools are reminded to follow the Guidelines on Prevention of Communicable Diseases on preventive and control measures as well as management of outbreaks. If an outbreak is suspected, schools should immediately report it to the CHP for prompt follow-up. Schools may also refer to the CHP’s pages on CF, DF, seasonal influenza, HFMD and EV71 infection for more information. Information on SIV is available on the CHP’s Vaccination Schemes page.