Surveillance enhanced amid winter influenza season
"Our latest surveillance data show that the local seasonal influenza activity steadily increased from baseline level and may rise further in the coming weeks. We again urge the public, particularly children, the elderly and chronic disease patients, to get vaccinated as soon as possible and observe strict personal, hand and environmental hygiene," a spokesman for the CHP said.
The positive percentage of seasonal influenza viruses among respiratory specimens received by the CHP increased from 8.17 per cent to 9.12 per cent from the week of January 15 to that of February 12. Most detections were influenza A(H3N2).
In the same period, the number of institutional outbreaks of influenza-like illness (ILI) increased from six (affecting 46 persons) to 13 (90 persons). The average ILI consultation rate among sentinel private doctors rose from 39.4 to 56.0 cases per 1 000 consultations in the same period, while that of General Out-patient Clinics increased from 4.0 to 5.3.
From February 24 onwards, the CHP will collaborate with the Hospital Authority and private hospitals to reactivate enhanced surveillance for severe seasonal influenza, i.e. influenza-associated admission to the Intensive Care Unit or death in adults aged 18 or above, to better monitor the severity of illness.
In children aged under 18, routine surveillance of severe influenza-associated complications or deaths is ongoing. In 2015, 2016 and 2017 to date, 25 (one death), 31 (four deaths) and three cases were recorded respectively. Among them, a total of 52 cases (88 per cent) did not receive seasonal influenza vaccination of the respective season.
The CHP will issue letters to doctors, hospitals, institutions and schools to appeal for heightened vigilance.
In this influenza season, schools should check the body temperature of all students every day when they arrive at school to identify those with fever. To prevent outbreaks, those with fever (oral temperature over 37.5 degrees Celsius or ear temperature over 38 degrees), with or without respiratory symptoms, should not be allowed to attend school. Schools should advise them to seek medical advice and avoid school till two days after fever subsides.
In addition, staff should check their temperature before work every day and those with fever or respiratory illnesses should refrain from work.
"Schools should promptly report to the CHP in case of an increase in respiratory illnesses or absentees for immediate epidemiological investigations and outbreak control. We will issue letters to kindergartens and child care centres as well as primary and secondary schools on the above additional measure," the spokesman said.
"We again remind the public, particularly children, the elderly and those with underlying illnesses, to get vaccinated as early as possible to prevent seasonal influenza as it takes about two weeks for antibodies to develop in the body after vaccination," the spokesman added.
As of February 19, about 389 000 and 274 000 doses of seasonal influenza vaccines had been administered via the Government Vaccination Programme (free vaccination) and the Vaccination Subsidy Scheme (subsidised vaccination) respectively, increasing by 5.4 per cent and 52.6 per cent from the same period in the last season.
The public should maintain good personal and environmental hygiene for protection against influenza and other respiratory illnesses:
- Receive seasonal influenza vaccination for personal protection;
- Wash hands with liquid soap and water properly whenever possibly contaminated;
- When hands are not visibly soiled, clean them with 70 to 80 per cent alcohol-based handrub;
- Cover the nose and mouth when sneezing or coughing, and wash hands thoroughly afterwards;
- Dispose of soiled tissue paper properly in a lidded rubbish bin;
- Put on a surgical mask when respiratory symptoms develop;
- Maintain good indoor ventilation;
- When influenza is prevalent, avoid going to crowded or poorly ventilated public places; high-risk individuals may consider putting on surgical masks in such places; and
- Maintain a balanced diet, exercise regularly, take adequate rest, do not smoke and avoid overstress.
The public may visit the CHP's influenza page and weekly Flu Express for more information.
Ends/Wednesday, February 22, 2017
Issued at HKT 16:30
Issued at HKT 16:30