Official Chinese bird flu deaths could be 'tip of iceberg'
By Debora MacKenzie A respected Japanese scientist, who works with the World Health Organization, has told New Scientist he fears that China’s official tally of laboratory-confirmed human bird flu fatalities – just three – is only the tip of the iceberg. Masato Tashiro, head of virology at Tokyo’s National Institute of Infectious Disease – a WHO-collaborating centre for bird flu – showed a slide at a meeting of virologists in Marburg, Germany, on 19 November listing “several dozen” outbreaks in people, nearly 300 deaths, 3000 people placed in isolation, and seven human-to-human transmissions. The meeting was reported in the German newspaper Frankfurter Allgemeine Zeitung. Tashiro has now told New Scientist that the figures were examples of the “unauthorised information” circulating in China, where he was helping to investigate recent outbreaks. Earlier reports suggested that Tashiro believed 300 to be the true death toll from bird flu in China. “I do not know whether the numbers were based on any evidence,” he says. But the message is that “we do not know how many cases actually occurred in China”, due to poor disease surveillance. “If surveillance is done more extensively, more cases may be detected.” He says the international community should assist China with monitoring. He describes the situation as an “iceberg phenomenon” – with most cases unreported. China has reported only three confirmed cases of H5N1 in people: a boy in Hunan province who recovered, and two women in Anhui province who died, the latest of which was announced on Thursday. There was another probable case in Hunan. The potential problem of underreporting may not only be technical. There are also claims that Chinese medical personnel have been arrested for trying to report cases. China enforced severe restrictions on the investigation and reporting of suspected cases of bird flu in June 2005. But the WHO says it does not believe China is deliberately hiding cases as it did during the SARS outbreak in 2003. “There are many countries where surveillance is weak and needs to be strengthened, I think that’s true in certain parts of China as well,” says Roy Wadia, a WHO spokesman based in Beijing. “We’re getting lots of information in a timely way about the outbreaks and we’re asked to be part of the ongoing investigations. I think that speaks for itself.” Virologists consider the relative absence of human cases of bird flu in China unusual, given its widespread infection in birds. China has reported 22 poultry outbreaks in 10 provinces all across the country since mid-October 2005, the latest being on Friday. The WHO told the official Chinese news agency Xinhua last week that the virus that caused the outbreak in Hunan is the same as the H5N1 flu in Vietnam and Thailand, where it has caused 113 confirmed human cases and 55 deaths so far. Bird Flu – Learn more about the flu pandemic that could kill millions in our continually updated special report. More on these topics: