http://www.newscientist.com/article.ns?id=dn8140
Bird flu outbreaks expected in more countries
18:51 17 October 2005
NewScientist.com news service

The deadly H5N1 strain of bird flu is likely to spread to more and more
countries, a World Health Organization official warned on Monday.

The strain, which has killed over 60 people in southeast Asia, appears
to have travelled extensively in the latter half of 2005. It has affected
birds in China, Mongolia, Russia, Kazakhstan and most recently reached
Europe.

“There is no question that we will expect further outbreaks of the
avian disease in different countries,” says Michael Ryan, the WHO’s director
of the department of epidemic and pandemic alert and response, in Geneva,
Switzerland.

Tests by the European Union reference laboratory for flu in Weybridge,
UK, confirmed on Saturday that the virus affecting birds in Romania was the
H5N1 strain, the day after coming to the same conclusion about sick turkeys
in Turkey.

Assessing risk
The strain shows similarities to the 1918 human flu virus – which may
have killed 50 million people – and is believed to pose a greater risk of
starting a new pandemic than other circulating strains.

“It’s important for us to remember that avian influenza and pandemic
human influenza are not the same things," Ryan says, and emphasises that the
chances of a person catching bird flu remain “extremely low”.

But he told New Scientist that the appearance of the deadly strain in
Turkey and Romania does pose an increased risk of a pandemic strain emerging.
The spread to more countries "in itself increases the risk of the virus
jumping to humans", he says, although he also points out that millions of birds
are affected in Asia, and so the bulk of the risk lies there.

Changing outlook
It is now believed that the virus has been carried and spread by
migratory birds. Previously, it was suspected that infected wild birds might have
become too ill to actually migrate, and shed the virus far and wide.

Previous outbreaks in Asia could be explained by the movement of
domestic poultry by people rather than migration of the birds themselves. Andre
Farrar, a spokesman for the UK’s Royal Society for the Protection of
Birds, says, for example, that the outbreak in wild migratory birds near
Qinghai Lake in China, appears to have come from local birds. And the Russian
and Kazakhstan outbreaks occurred along a railway route.

“But Turkey and Romania changes things. The outbreaks are entirely
consistent in terms of the location and timing of bird migration,”
Farrar told New Scientist.

The incursions by the virus into Europe are on a “flyway” which runs
from Central Russia to Turkey and Eastern Europe, then on to the Middle East
and down to East Africa.

Continental risks
The outbreak in backyard poultry in eastern Romania “is near to an area
supporting large numbers of water birds in the Danube delta”, notes a
risk-assessment report by the UK government, published on Saturday. The
outbreak in the Balikesir region of northwest Turkey is close to Kus
Lake, which also supports significant numbers of water birds.

If migratory birds are carrying the virus along their “flyways”, this
may mean other continents are at risk. Ryan revealed that WHO had been in
talks with North African ministers last week regarding the possible
introduction of bird flu into Africa.

“The Americas, Africa and the Middle East are very much in our minds,”
says Ryan. He urges that it is a “public health responsibility for each
country to be ready”. “We must prepare for an inevitable [human] pandemic at
some point – now or in the distant future.”