CHINA - No new human cases of the H7N9 virus have been recorded in China for a week, national health authorities said, for the first time since the outbreak began in March.
One previously infected patient died in the week beginning May 13, the National Health and Family Planning Commission said in a statement late Monday, taking the total number of fatalities from the virus to 36.
But the number of confirmed cases was unchanged at 130. Of those, 72 have recovered and been discharged from hospital, it said, adding that no evidence of human-to-human transmission had been detected so far.
Experts fear the possibility of the virus mutating into a form easily transmissible between humans, with the potential to trigger a pandemic.
Flu viruses are often seasonal and much of China is experiencing warmer weather following the end of winter.
But the head of the World Health Organisation (WHO) warned that the evolution of the outbreak was still unpredictable.
"Influenza viruses constantly reinvent themselves. No one can predict the future course of this outbreak," Margaret Chan said Monday at the World Health Assembly in Geneva.
"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 poultry markets," she added.
China was accused of covering up the outbreak of Severe Acute Respiratory Syndrome (SARS) that killed about 800 people around the world a decade ago, but Chan thanked authorities for their close collaboration with the WHO over H7N9.
A Nobel prize-winning scientist Tuesday played down "shock-horror scenarios" that a new virus strain will emerge with the potential to kill millions of people.
Peter Doherty, who jointly won the Nobel prize in 1996 for his work on how the immune system combats virus-infected cells, said the worst-case scenario was a new virus with a high mortality rate that was also highly infectious.
The Australian said the world experienced such a pandemic in 1918, when an influenza variant killed an estimated 50 million people, more than twice the number who died in World War I.
Doherty said it was possible such an outbreak could occur again but it was unlikely to have such devastating consequences.