The confirmation of two new outbreaks of the deadly H5N1 strain of bird flu in poultry in China is causing concern among health experts as the virus continues to take its toll on Asia, and the world searches for ways to contain it.
China has already culled more than 20 million birds this year and has reported 24 outbreaks of avian influenza since mid-October in nine regions and provinces from the far southwest to the frigid northeast.
The latest cases were diagnosed in the northwestern region of Xinjiang and in central Hunan province.
The deadly H5N1 strain is known to have infected 133 people in Asia since late 2003, killing 68.
Although it is hard for people to catch, experts fear it could mutate and become easily passed from person to person, sparking a global pandemic in which millions could die.
If this should happen western investment banks are warning clients of dire consequences for the world economy, although as yet there has been little reaction on financial markets other than a rise in some drug company stocks.
Health experts globally are continually examining ways of preventing the virus spreading and as an example Dutch scientists said this week that vaccinating chickens could stop the virus from being passed on.
The United Nations has advised against culling wild birds, saying the main concern must be tackling the disease in poultry.
The U.N.'s Food and Agriculture Organisation (FAO) issued that advice after reports that wild birds were being killed in Ho Chi Minh City in Vietnam as a precautionary measure.
Juan Lubroth, an FAO official with responsibility for infectious animal diseases, said the action was unlikely to make any significant contribution to the protection of humans against avian influenza.
In the latest development the World Health Organisation (WHO) has said the possibility of human-to-human transmission of bird flu in Indonesia could not be ruled out after the deaths of two brothers of a 16-year-old boy confirmed as Indonesia's 12th human case of bird flu.
WHO spokeswoman Maria Chang says the brothers apparently died on Nov. 11 from similar symptoms days before the boy from West Java was taken to hospital.
At the time the boys were diagnosed with typhoid fever, but were never tested for the deadly H5N1 bird flu virus, leaving questions hanging over the cause of death.
Europe's health chief Markos Kyprianou said in Brussels that creating an EU-wide stockpile of vaccines to contain a major flu outbreak should be encouraged but he preferred countries to do everything on their own to prepare for the worst scenario.
Speaking after a two-day simulation to test how well the EU would cope with a wide-scale health scare, especially of influenza, the EU Health and Consumer Protection Commissioner said there was a clear need to strengthen vigilance.
EU member states have drawn up plans to deal with a flu pandemic and organise national stockpiles or orders for antiviral drugs antiviral drugs, and their levels of preparedness vary widely.
Whether there will be a European stock is a policy decision.
He says he believes that there are arguments in favour of such a policy.