Controller of the Center for Health Protection of the Hong Kong
government Dr. Thomas Tsang said Saturday they have ruled out the
possibility of human-to-human transmission after tests on a
nine-month baby's recent infection of H9N2, a mild form of avian
influenza.
Speaking on a radio talk show on Saturday, Dr. Tsang said
genetic sequencing studies of the virus isolated from the
nine-month-old girl recently hospitalized for H9N2 showed all genes
from the virus are of avian origin.
Dr. Tsang said the results suggested the virus was directly
transmitted from a bird to the girl, without mingling with a human
flu virus.
As the girl did not contact wild birds before the onset of the
symptoms, Dr. Tsang said she may have contracted the virus at the
Tseung Kwan O market in Hong Kong's New Territories she visited
several times with her family.
Noting tests on respiratory specimens taken from a healthcare
worker and three children who were in the same cubicle in the
United Christian Hospital with the girl in early March were all
negative for the H9 virus and her family members have no symptoms,
Dr. Tsang said the case did not involve human-to-human
transmission.
However, he said children with poorer immunity may be more prone
to the virus as H9N2 cases recorded in 1999 and 2003 also involved
children aged below five.
On average samples of 40,000 flu cases will be tested a year for
surveillance, Dr. Tsang said both H5 and H9 viruses are related to
birds and can be transmitted from birds to humans, but the former
has a mortality rate of 70 percent while the latter is a mild form
of avian flu and its symptoms are similar to common colds and
flu.
When asked whether global warming will lead to virus mutation,
Dr. Tsang said there is no direct link between the weather and
virus reassortment, but warm weather will favor the breeding of
germs and communicable disease vectors.
(Xinhua News Agency March 25, 2007)