​The Centre for Health Protection (CHP) of the Department of Health (DH) today (August 30) urged schools, parents and students to heighten vigilance and adopt good personal and environmental hygiene to prevent the spread of communicable diseases as social contact among students in schools will increase when school resumes.
According to previous experience, the CHP expected that outbreaks of respiratory infections and hand, foot and mouth disease (HFMD) in schools may increase after the start of the new school year and reminded schools to stay vigilant and take preventive measures to guard against possible outbreaks. Moreover, in view of the increase of imported Dengue Fever (DF) cases this year coupled with detection of local DF cases, schools should take active mosquito prevention measures.
A. Respiratory infections
The latest surveillance data of the CHP showed that some respiratory pathogens remained active in the community. For children, laboratory surveillance data from the Hospital Authority (HA) over the past eight weeks (as of August 24) revealed that the detection rate of Mycoplasma pneumoniae and Respiratory Syncytial Virus (RSV) continued to increase. The latest rate accounts for 12 per cent and 8 per cent respectively, which have been increased from around 10 per cent and 6 per cent respectively compared to eight weeks ago but are in line with previous seasonal trends. In general, rhinovirus/enterovirus continued to have the highest activity level amongst respiratory pathogens, accounting for more than 15 per cent of the paediatric respiratory specimens received by the HA, though the proportion in recent days has started to drop.
For COVID-19 and seasonal influenza (SI), the activity of COVID-19 which had increased since late June this year showed signs of decline recently. The weekly detection rate of respiratory specimens tested positive for SARS-CoV-2 virus decreased from 9.06 per cent in early August to 6.16 per cent in the week ending August 24. The overall SI activity has remained at a low level since the end of influenza season in late July. However, with reference to the previous surveillance data, the CHP expected that activity of COVID-19 and SI may increase at the end of the year and more school outbreaks will be reported.
Seasonal influenza vaccination (SIV) can provide protection against influenza infection, and lower the chance of serious complications and death brought about by infection. Parents are advised to arrange for their children to receive SIV for better personal protection by participating in the SIV school outreach activities or visiting their family doctors in the new school year. Research studies have shown that SIV among children may potentially reduce school absenteeism. Parents should note that it takes about two weeks for the body to develop a sufficient level of antibodies to protect against influenza infection after vaccination, so they should receive vaccination early before the winter.
The DH has sent letters to all schools in Hong Kong through the Education Bureau inviting them to participate in the SIV school outreach vaccination programmes. The choice of vaccine options will be more flexible under the 2024/25 Seasonal Influenza Vaccination School Outreach Programme. Kindergarten and child care centres can choose to provide both injectable inactivated influenza vaccines and live attenuated influenza vaccines (i.e. nasal vaccines) (LAIV) at the same or different outreach vaccination activities. Schools can also invite doctors to arrange outreach service for injectable inactivated influenza vaccines and/or nasal LAIV at their campus under the Vaccination Subsidy Scheme School Outreach. According to local experience, the vaccination rate could prominently increase by more than double if school participated in the outreach programmes, and this will effectively strengthen the immunity barrier of schoolchildren. Schools which have yet to participate should enrol as soon as possible.
B. Hand, foot and mouth disease
HFMD is a common disease in children usually caused by enteroviruses such as coxsackie viruses and EV71. In Hong Kong, the peak season for HFMD is usually from May to July and a smaller peak may be observed from October to December. This year, the HFMD activity recorded a slight increase between April and August. As of August 29, the CHP recorded a total of 230 HFMD outbreaks this year, returning to the pre-pandemic level.
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. As the virus can easily spread through close contacts among students and a smaller peak usually occurs from October to December, the CHP expects that outbreaks of HFMD in schools will continue to occur after the start of the new school year. 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.
C. Dengue fever
As of August 29, the CHP has recorded 54 DF cases this year, which marks an increase of over 50 per cent of cases compared with 34 cases recorded during the same period last year. Four of the cases recorded this year are local DF cases and the other are imported cases.
To prevent the recurrence of local transmission of DF, schools should take measures to strengthen work in preventing the accumulation of water and removing potential breeding grounds of mosquitos, such as changing water for plants at least once a week, covering all water containers, and keeping all drains free from blockage etc. The school management is advised to appoint designated staff for mosquito prevention and control in the school premises. Details are available from the guidelines published by the Food and Environmental Hygiene Department.
A spokesman for the CHP said, "The CHP has issued letters to primary and secondary schools, kindergartens and childcare centres to remind them to stay alert. If students or staff develop fever, respiratory symptoms, diarrhoea, vomiting or skin rash, schools should strongly advise them not to return to campus and to promptly seek medical advice. Management of schools should observe precautions on campus, such as maintaining good environmental hygiene and indoor ventilation, to lower the risk of possible transmission of diseases in the school."
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 SI, DF, HFMD and EV71 infection for more information. Information on SIV is available on CHP's Vaccination Schemes page.
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