A Bangkok toddler has tested positive for bird flu, while China confirmed more cases and Japan drew up an action plan to tackle any outbreak of the disease which has swept Asia and spread into Europe.
The one-year-old boy probably contracted the H5N1 virus from playing at home around chickens which later died of the virus, Paijit Warachit, director-general of the Department of Medical Science, said on Saturday.
The highly pathogenic H5N1 virus is endemic in poultry across Asia, where it is known to have infected 124 people and killed 64. Millions of birds have been culled.
Although H5N1 has yet to be transmitted between people, experts fear it could mutate into a strain that can move easily from person to person, touching off a pandemic that could kill millions.
Migratory birds have spread the disease into eastern Europe and on Friday Kuwait said it had found H5N1 in a flamingo. It was the first known case of bird flu in the Gulf region.
The Thai boy is the first human case in Bangkok since a fresh flare-up of the deadly disease there a month ago. The virus has killed 13 Thais since it swept across large parts of Asia in late 2003.
Worried about a possible mutation into a transmittable killer human virus, Japan has drafted plans to tackle an epidemic, including closing schools around infection zones and declaring a state of emergency if an outbreak spread to a wide area.
Asahi Shimbun daily said the government programme assumed that one in four people in Japan would be affected if an outbreak occurred.
The government estimates that between 170,000 to 640,000 people could die and that between 530,000 to 2 million people could be hospitalised, Asahi said.
Japan will also aim to increase stockpiles of the antiviral drug Tamiflu so there will be enough for 25 million people to be treated over five days, rather than just three days under a previous target, Asahi said.
Hong Kong is already bracing for an explosion of cases early next year, a Chinese-language daily said on Saturday.
Scientists in Hong Kong said H5N1 apparently causes a "storm" of immune system chemicals that overwhelms the patient.
The study, published in the online medical journal Respiratory Research, might suggest that if H5N1 does cause a pandemic, it could disproportionately affect the young and healthy as compared with seasonal flu, which kills many elderly people but few young adults.
Meanwhile, Hong Kong's government said China had confirmed a fresh outbreak of the H5N1 virus in poultry.