There is no evidence that the deadly H7N9 bird flu has yet spread between humans in China but health authorities seem ready for the virus to mutate at any time, a top US virologist has warned.
Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases (NIAID), said officials in China had studied more than 1,000 close contacts of confirmed cases and not found any evidence of human-to-human transmission. What’s bothersome is that there have been cases where no contact to poultry has been found. These cases leave an open door when it comes to the source of infection.
“That is powerful evidence because if you had a thousand contacts with someone with the flu you would be pretty sure some of them would have been infected,” Fauci said in an interview with AFP.
Nevertheless, Fauci cautioned that authorities needed to be ready for the possibility of the virus mutating and spreading between humans.
“It’s unpredictable as are all the influenza. One of the things we need to be concerned about is this might gain the capability of going human-to-human which up to this point has not happened and is somewhat encouraging news,” Fauci said.
“But we still need to be very prepared for the eventuality of that happening.”
Researchers are already developing a diagnostic test to identify H7N9, along with a vaccine, with clinical trials due in July or August. Influenza viruses constantly change and it’s possible that this virus might become able to easily and sustainably spread between people, triggering a pandemic.