Proper surveillance can stop flu pandemic

[Guest guest]

INTERVIEW-Proper surveillance can stop flu pandemic-expert

Sat Mar 29, 2008 11:02pm EDT By Tan Ee Lyn

HONG KONG, March 30 (Reuters) - An influenza pandemic can be avoided

if proper disease surveillance and control measures are carried out

promptly and thoroughly, leading bird flu expert and microbiologist Yi

Guan said.

Guan, who studied the H5N1 bird flu virus after it showed up in people

in Hong Kong in 1997 and has tracked its footprints all over the world

ever since, is convinced that the world can stop the bug in its tracks

if it has enough resolve.

" If proper surveillance is in place for animals and humans, yes, we

can stop pandemic influenza forever. Not just for H5N1, it may also

work for other subtypes of viruses, " he said in an interview over the

weekend.

" We have the ability to remove pandemics if we have a long-term strategy. "

Guan, a professor at the University of Hong Kong, knows just how

backbreaking and mundane surveillance work can be.

He and his researchers have tested more than 200,000 stool samples of

chickens, aquatic and wild birds collected from various parts of China

since 2000, screening them for the H5N1 virus which experts say could

cause the next flu pandemic, killing millions of people.

The university laboratory where Guan works is a World Health

Organisation reference facility that also helps to analyse H5N1

samples from other parts of the world, particularly Asia.

Here, Guan has been able to compare H5N1 samples, trace mutations in

the virus and track its footprints.

Last week, he and his colleagues published a paper in the Journal of

Virology hypothesizing that the H5N1 strains which showed up in

Vietnam, Thailand and Malaysia in late 2003 probably originated in

China's southwestern Yunnan province.

" Based on their genetic inter-relationships, they are likely from

Yunnan. We detected almost identical viruses in Yunnan in late 2002

and early 2003, " he said.

POULTRY TRADE

The paper said poultry trade might have been responsible for the

introduction of the virus into Vietnam.

" As for the Indonesian virus (which showed up in November 2003), that

was detected in (China's central) Hunan province in 2002 and 2003, "

Guan added.

The paper did not postulate how the virus got into Indonesia.

Guan said all the years of H5N1 surveillance in Hong Kong and China,

and many other parts of the world had paid off.

Although experts have warned of an H5N1 pandemic for years now, the

virus remains largely a bird disease. Since late 2003, it has infected

only 373 people, although its substantial killing power has left 236

of them dead.

" For disease control, surveillance must be a long term effort. You

know where it is and you know it is coming, like a spark of fire you

can extinguish it, " Guan said.

" If not for all this surveillance and detection ability, the pandemic

would probably have already come. "

Drawing from what is known of past pandemics, Guan believes that

surveillance and strict control measures are the answers.

" Pandemics don't happen suddenly, they have an early phase, mature

phase, outbreak phase. The virus changes step by step, it takes a long

cooking time, " he said.

" If a virus gets into humans in the early phase, the transmission

ability is very low. At most, they infect their families, but it can't

go further into the community.

" This phase is the golden point to control. Once it matures and

becomes (efficient in) human-to-human (transmission), it will be too

late. " (Editing by )

http://www.reuters.com/article/europeCrisis/idUST16178