All sectors of the community should heighten vigilance and enhance personal protection against influenza, including getting vaccinated, as the seasonal flu and respiratory infectious diseases in Hong Kong may increase in the coming weeks, the Department of Health said on Thursday.

Hong Kong has entered the influenza season, said Centre for Health Protection (CHP) Controller Dr Edwin Tsui Lok-kin.

According to data up until Jan 4, the percentage of respiratory specimens testing positive for seasonal influenza viruses was 5.69 percent, and the influenza admission rate in public hospitals was 0.36 cases per 10,000 population.

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“Both indicators have exceeded the thresholds of 4.94 percent and 0.27 cases per 10,000 population respectively, indicating that Hong Kong has entered the influenza season,” Dr Tsui said.

The majority of positive detections were influenza A (H1), accounting for around 90 percent, he added.

The number of reported influenza-like illness outbreaks started to rise after the Christmas and New Year holidays, with a total of seven institutional/school outbreaks, affecting 45 people, in the week ending Jan 4, according to the CHP.

This was more than double the number of outbreaks in December of between two and four per week, it added.

The number of influenza-like illness outbreaks is expected to continue to increase, and outbreaks in schools may be greater than elsewhere, the center said, adding that it has written to schools reminding them to take additional measures to reduce transmission. It will also write to doctors, hospitals and institutions to appeal for heightened vigilance.

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Based on previous surveillance data, virus activity will continue to increase for a period of time after the start of the influenza season before peaking, said Dr Tsui.

“Members of the public who have not yet received seasonal influenza vaccination (SIV), particularly the elderly and children who have higher risk to get infected with influenza and other complications, should receive SIV immediately to lower the risk of serious complications and death.”

As of Jan 5, about 1,832,000 doses of vaccines had been administered under various vaccination programs, marking an increase of about 5.4 percent over the same period last year. However, 168 schools have still not agreed to arrange SIV outreach activities for students, while another 13 schools have agreed to do so but have failed to fix jab dates.

Dr Tsui appealed to parents with children at these schools to bring them to receive an SIV as soon as possible. He also strongly urged the 13 schools who have failed to fix dates to do so as soon as possible within the next two weeks.

The SIV coverage rate for children aged six months to under two years remained relatively low at about 17.4 percent, lower than that for other age groups of children.

To enhance vaccination services and boost the vaccination rate, the special administrative region government has opened the Department of Health’s Maternal and Child Health Centres to this group of children. Parents may book an appointment for them online.

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Reminding high-risk individuals to wear a surgical mask when visiting public places, the CHP controller urged the public to consider wearing a surgical mask while taking public transportation or going to crowded places.

People with respiratory symptoms, even if mild, should wear surgical masks and seek medical advice promptly, and should also consider staying away from work or school, he added.