HONG KONG: The A (H1N1) influenza is expected to become highly active this summer. New research reveals the likelihood that hospital admission will accelerate.

The Chinese University of Hong Kong (CUHK) and the Hong Kong Observatory (HKO) conducted the study enquiring into the relationship between weather and influenza outbreaks in the city.

In an archival study of confirmed flu cases admitted to the Prince of Wales Hospital (PWH) correlated to weather data in Sha Tin from 1997 to 2006, researchers found that the number of admissions owing to influenza A during summer has been rising.

"This implies that the summer peak is getting more severe," said CUHK microbiology professor Paul Chan Kay-sheung.

Two seasonal peaks of influenza A occur from February to March and June to July. The virus becomes more active during the hot, humid summer and in the wet, cold winter, the study found.

Chan warned that summer conditions will likely promote an A (H1N1) influenza outbreak capable of requiring a high rate of hospital admissions.

In 1998, almost 130 patients were admitted to PWH every week owing to the mutated virus named the Sydney influenza A infection. Chan predicted the H1N1 swine flu would not be any less virulent than the Sydney strain.

He advised the public to get vaccinations around November and no later than December to acquire the greatest effectiveness in warding both the winter and summer seasonal peaks.

Maximum protection following vaccination can sustain for only a few months. so it is important to be vaccinated neither too early nor too late.

"However, vaccination against human swine flu should be received once it is ready as the virus is a new one and most people don't have the antibodies," Chan added.

(HK Edition 06/19/2009 page1)