Singapore: The World Health Organization (WHO) director general, Dr Margaret Chan, assured that the immediate threat from the H7N9 avian influenza virus is over.

Speaking at the 66th World Health Assembly in Geneva, Switzerland, Dr Chan pointed out that no new laboratory confirmed cases of human infection with H7N9 virus have been reported to the WHO since May 8. She further pointed out that four additional deaths have been reported by the National Health and Family Planning Commission in China from the previous confirmed cases.

As per the WHO statistics, 131 laboratory-confirmed cases, including 36 deaths have been reported from the country. Appreciating the swift response by China in closing live poultry markets, Dr Chan said that this was the reason number of new cases dropped dramatically.

"At the end of March this year, China reported the first-ever human infections with the H7N9 avian influenza virus. Within three weeks, more than 100 additional cases were confirmed. Although the source of human infection with the virus is not yet fully understood, the number of new cases dropped dramatically following the closing of live bird markets," she said.

Unlike with the severe acute respiratory syndrome (SARS) virus, no human-to-human transmission was detected with the H7N9 virus and all cases were traced to contact with live poultry.

"I thank China for collecting and communicating such a wealth of information, and for collaborating so closely with WHO. Chinese officials have promptly traced, monitored, and tested thousands of patient contacts, including hundreds of health care workers," she added.

Warning that these microbes has a tendency to deliver surprises, Dr Chan explained, "Constant mutation and adaptation are the survival mechanisms of the microbial world. Going forward, we must maintain a high level of vigilance. I cannot overemphasize the importance of immediate and fully transparent reporting to WHO, and of strict adherence to your obligations set out in the International Health Regulations. I ask Member States to do everything they can to ensure that health occupies a high place on the new development agenda."