Olympic host city Beijing, neighbouring northern Hebei province and the south-western Chongqing municipality were the latest to report cases yesterday, adding to the growing list of areas hit by China's most severe outbreak of HFMD in recent years.

The health authorities in Beijing said 1,482 children have taken ill, according to state media yesterday.

But the outbreak in the Chinese capital is not a threat to the August Games as it affects mostly young children, the World Health Organisation's (WHO) China representative, Dr Hans Troedsson, told reporters on Sunday.

Elsewhere in China, children - most under the age of six - have fallen ill in Anhui, Guangdong, Jiangsu, Hunan, Zhejiang and Hubei provinces.

Eastern Anhui province and southern Guangdong province are the worst hit. State media reported that 26 children have died.

Enterovirus 71, or EV-71 - the most vicious strain of the viruses which cause HFMD - has been blamed for the deaths of 22 children in Fuyang city in Anhui, three children in Guangdong and one in eastern Zhejiang province.

Around Asia, the virus has affected children in Hong Kong, Singapore, Taiwan and Vietnam.

HFMD, which could be caused by more than 60 viruses, is a common illness among children. It often starts with a fever, followed by blisters and ulcers in the mouth, and rashes on the hands and feet. Although highly contagious, the disease is usually mild and children recover within four to six days.

Dr Jeffery Cutter from the Communicable Diseases Division of Singapore's Ministry of Health said EV-71 seems to rear its head every two to three years.

'It is uncertain why certain viruses are more dominant in one year rather than another,' he said, but said it could be due to a build- up in the number of non- immune children in the interim period.

Singapore has seen more than 9,000 cases. EV-71 is responsible for one in five of the HFMD cases.

China this year also saw many more cases triggered by EV-71. In some cases, children infected with EV-71 can develop viral meningitis, encephalitis, pulmonary edema and paralysis. There is no vaccine.

Mr Peter Cordingley, WHO's spokesman for the Western Pacific region, said there is no connection between the various HFMD outbreaks across Asia.

'These are all localised infections inside the affected countries,' he told The Straits Times.

Dr Troedsson told The Straits Times the disease is prevalent during warmer weather.

Referring to Anhui, he said: 'From my discussions with the (Chinese) Ministry of Health, one thing was that this province was affected by snow storm..but after that, it had an unusual warm spell early this year - the question is if it was a bit warmer. But that's speculation, we don't know.'

tracyq@sph.com.sg