The Centre for Health Protection (CHP) of the Department of Health (DH) today (September 6) reminded schools, parents and students to heighten vigilance and maintain good personal and environmental hygiene to prevent the spread of communicable diseases in schools as social contact among students in schools has increased with the start of the new school year.

     "As schools are collective assembly places, infectious diseases could be easily spread among people through their daily contacts. In view of this, the CHP has issued letters (www.chp.gov.hk/files/pdf/letter_new_school_year_19_20_eng.pdf) to schools, kindergartens and child care centres to remind them on continued vigilance and reinforcement of preventive measures to guard against possible outbreaks," a spokesman for the CHP said.

A. Seasonal Influenza

     The surveillance data of the CHP showed that the overall local influenza activity remained at a low level, but outbreaks of influenza-like illness in schools may increase after the start of the new school year. Although influenza is usually self-limiting, it may cause serious illness even in healthy children.
 
     Parents are advised to arrange for their children to receive seasonal influenza (SI) vaccination later for personal protection before the winter season arrives. Parents are reminded that it takes about two weeks for the body to develop a sufficient level of antibodies to protect against influenza virus infection after vaccination.

     "If staff or students 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 in the campus, such as maintenance of environmental hygiene and good ventilation, to prevent possible transmission of diseases," the spokesman said.

     For more information on SI vaccination, parents may call the CHP hotline at 2125 2125 or visit the CHP's Vaccination Schemes page. 

B. Dengue fever
 
     Regarding the latest dengue fever (DF) situation in Hong Kong, from August 30 to September 5, the CHP recorded four imported DF cases. The patients had been to India (two cases), Malaysia (one case) and Thailand (one case) during the incubation period.

     As of yesterday (September 5), 138 cases had been recorded this year, as compared with 100 cases recorded in the same period last year. All the cases recorded in 2019 were imported, mainly from Thailand (29), Malaysia (24) and Cambodia (19).     

     Schools should take the following preventive measures to prevent accumulation of stagnant water and eliminate mosquito breeding sites:
 

• Put all used cans and bottles into covered dustbins;
• Change water for plants at least once a week, and avoid using saucers underneath flower pots;
• Cover tightly all water containers, wells and water storage tanks;
• Keep all drains free from blockage; and
• Top up all defective ground surfaces to prevent the accumulation of stagnant water.

 
     Staff and students are also advised to protect themselves from mosquito bites by taking the following measures:
 

• Use mosquito screens or bed nets when the room is not air-conditioned; and
• Place anti-mosquito devices near entrances such as windows and doors to prevent mosquitoes from entering indoor areas.

  
     Furthermore, 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:
www.fehd.gov.hk/english/pestcontrol/library/pdf_pest_control/mosquito_school.pdf.

C. Chickenpox

     Chickenpox is the most common notifiable infectious disease in Hong Kong and is highly communicable as it can be spread through droplets or air. It can also be spread through direct or indirect contact with the discharges from vesicles and mucous membranes of persons with chickenpox or herpes zoster. Children are most affected. Locally, there are two seasonal peaks. The number of chickenpox cases usually starts to rise in October and peaks in December and January, while a smaller peak is also observed in June and July.

     A total of 202 institutional chickenpox outbreaks affecting 1 139 persons had been recorded in 2019 as of August 22, including 38 outbreaks (114 children) in kindergartens or child care centres and 138 outbreaks (908 pupils) in primary schools. Up to August, 4 570 chickenpox cases had been reported this year, which is similar to the figure for the same period last year.

D. Hand, foot and mouth disease and enterovirus infection

     In Hong Kong, the usual peak season for hand, foot and mouth disease (HFMD) and enterovirus 71 (EV71) infection is from May to July and a smaller peak may also occur from October to December. This year, the HFMD activity started to increase in May and has stayed at a high level throughout July and August. As of August 31 this year, 402 institutional outbreaks of HFMD had been recorded by the CHP, which is higher than the 238 cases in the same period last year, while the figure for EV71 infections this year (five cases) was lower than that in the same period of last year (36 cases).

     The CHP expects that outbreaks of HFMD in schools will continue to occur after the start of the new school year. Enterovirus infection is transmitted by direct contact with nose and throat discharges. The spokesman reminded that children suffering from HFMD and enterovirus infection should stay at home and should not go to school until they have recovered in order to prevent spread in campus.
 
E. Scarlet fever

     Scarlet fever (SF) is transmitted through either respiratory droplets or direct contact with infected respiratory secretions and mostly affects children.

     The local SF activity is usually higher from November to March and from May to June. It is expected to increase after the start of the new school year. As of August 31, 981 SF cases had been reported to the CHP this year, representing a decrease from 1 445 cases in the same period last year.

     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, chickenpox, HFMD and EV71 infection and SF for more information.

Ends/Friday, September 6, 2019
Issued at HKT 16:45

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