As the number of newly reported bird flu cases rose sharply in China, experts and officials say there is still no sign that the recent strain of avian influenza is being transmitted between people.
A total of 31 people died from H7N9 strain of bird flu in mainland China in January, out of a total of 127 confirmed cases, according to government figures released on Monday.
The figure compares with 144 confirmed cases for the whole of last year, of which 46 were fatal, the China's National Health and Family Planning Commission said in a statement.
Health experts worry that a form of avian influenza could mutate into a more resilient strand capable of causing a global pandemic in which millions would die.
Chinese officials and state media have sought to play down such fears.
"So far the features of human infection of the H7N9 bird flu have not had obvious changes and most cases remained sporadic," health spokesman Yao Hongwen told reporters on Monday.
"Our monitoring has not found any ... mutation in the virus and the way the virus spreads remains poultry-to-human."
Hong Kong experts agree
Top Hong Kong health experts, who were quick to criticize the ruling Chinese Communist Party's lack of transparency during the SARS epidemic of 2003, appear to agree with Beijing, saying that a virus without the H5 prefix has never been known to transmit between humans.
The outbreak of severe acute respiratory syndrome (SARS) spread from Guangdong, in south China, to other Asian countries and by the summer of 2003, when the disease was contained, more than 8,000 people had been infected, and over 900 people had died, according to figures from the World Health Organization.
According to Tze Wai Wong, professor at the Jockey Club School of Public Health and Primary Care in Hong Kong, the risk of a mutation still appears low for H7N9.
"There have been quite a few more cases in the past couple of months, but it could be that officials in all districts are now paying far more attention to the case numbers now," Wong said.
"It doesn't mean there weren't so many before."
He said there was no way to know if the spike in cases was simply a sharp rise in those cases reported to health officials.
"I am of the opinion that there is no evidence of human-to-human transmission," Wong added. "So the risk is still pretty low [from H7N9]."
"It will be time to worry when the virus acquires new genes that enable it to jump between people," he said.
Meanwhile, Yao said Chinese researchers are developing vaccines for the disease and one has passed a safety test on animals, although clinical trials in humans have yet to begin.
But former Hong Kong Medical Association (HKMA) president Gabriel Choi said the vaccine hadn't been developed under international guidelines.
"If the vaccine is still in clinical trials, it shouldn't be rushed to market, no matter how bad the situation is," Choi told RFA's Cantonese Service.
"According to the World Health Organization, the trials should be completed no matter what the situation," he said.
China's health officials are now calling for an end to traditional live poultry markets favored in rural areas, as they provide an ideal environment for the spread of avian influenza viruses between birds.
Authorities in the eastern province of Zhejiang has recently said it will ban all live poultry markets in major cities from July 1 and shutter similar facilities for three months from Feb. 15.
Reported by Yang Fan for RFA's Mandarin Service and by Wei Ling and Bi Zimo for the Cantonese Service. Translated and written in English by Luisetta Mudie.