Hong Kong announces end of summer influenza season

The Health Department of China's Hong Kong Special Administrative Region (SAR) on Wednesday announced the end of the summer influenza season and advised the public to maintain personal and environmental hygiene.

"The seasonal influenza (SI) activity increased steadily in June and rose sharply to a very high level in mid-July with some surveillance parameters surpassing their highest levels in recent years. It decreased notably in early August and returned to a baseline level in late August," said a spokesman for the Centre for Health Protection (CHP) of the Department of Health.

The spokesman said that Hong Kong entered the summer influenza season in mid-May, earlier than the past seasons that usually occurred from July to September.

The positive percentage of SI viruses among respiratory specimens received by the CHP peaked at 40.86 percent in the week of July 9. It dropped from 12.79 percent to 8.90 percent from the week of Aug. 13 to that of Aug. 20.

In the same period, the number of institutional outbreaks of influenza-like illness decreased from seven, which affected 25 persons, to two, which affected 10 persons. As of Tuesday, only one outbreak affecting five persons has been recorded this week.

The average daily number of influenza cases admitted to public hospitals peaked at 350 per day during the seven-day period from July 11 to July 17, and then steadily decreased to 32 per day from Aug. 23 to Aug. 29.

Regarding severe influenza cases, in adults, 576 cases of influenza-associated admission to the Intensive Care Unit or death, including 428 deaths, were recorded from May 5 to Aug. 29 in the enhanced surveillance with the Hospital Authority and private hospitals.

Among children, in the same period, 19 cases of severe influenza-associated complication or death, including three deaths, were detected. The last case was reported on Aug. 2.

The average daily number of severe cases among all ages peaked at 11.3 per day in the seven-day period from July 12 to July 18, and then gradually decreased to 2.7 per day from Aug. 23 to Aug. 29.

"Although the summer influenza season has ended, the public should continue to adopt strict personal, hand and environmental hygiene practices against respiratory illnesses and other infectious diseases," the spokesman said.