An outbreak of avian influenza ('bird flu') among villagers in Thailand is raising fresh fears that spread of the virus, which has killed 75 per cent of infected people, could in principle reach pandemic proportions.
The concern centres on the case of a Thai woman, Pranee Thongchan, who died of bird flu on 20 September after visiting her ill daughter, who is also thought to have died of the disease, but who was cremated before tests could be conducted.
If confirmed, Mrs Pranee's death will be the first caused by catching the disease from another person, rather than from contact with infected birds.
Speaking at a press conference at the UN Palais de Nations in Geneva yesterday (28 September), Klaus Stöhr, coordinator of the World Health Organisation's global influenza programme, said that bird flu had previously been transmitted between people. But in those cases — in Hong Kong in 1997 and in Vietnam this year — it was what he described as "inefficient, dead-end street transmission", meaning that although the virus was spread, it was unable to continue spreading or cause death.
Stöhr stressed that the Thai case could also be also be such a dead-end transmission. But he added that the outbreak could also indicate the beginning of more widespread transmission between humans, which could lead to the global spread of the virus.
The Thai deaths have heightened fears that the bird flu virus has mutated into a form that can be spread by humans. If this were to occur, or if the bird flu virus was to combine with the human flu virus to create a readily-transmitted form of the frequently fatal disease, the threat of a pandemic would become real.
"We want to see the virus before we draw any conclusions," said Stöhr, referring to tests currently being carried at the US Centre for Disease Control in Atlanta, on samples taken from Thailand. But he gave a clear warning that few countries are in a position to deal with the threat bird flu poses. "Currently, only 50 countries have pandemic preparedness plans."
"We feel there's too little [development work] done on vaccines," added Stöhr. "We have a window of opportunity now to work on it. It's a relatively low cost investment if you compare with the possible implications of a pandemic."
On Monday (27 September), two United Nations bodies — the Food and Agriculture Organisation and the World Organisation for Animal Health — released a joint statement warning that bird flu was now "a crisis of global importance", and that the virus is unlikely to be eradicated in the near future.
The recent deaths bring to 30 the number of people in Thailand and Vietnam who have died from bird flu this year. According to reports in the Bangkok Post, Thailand's ministry of public health says there are an additional 18 suspected and two confirmed cases of bird flu in the country.