As China continues to deal with growing cases of humans being infected with a new strain of bird flu, health experts are still try to figure out how people are becoming infected even though they have had no recent contact with live fowl and the virus isn't supposed to pass from person to person.
The H7N9 virus has already killed 17 and left at least 82 people sick since March. It is so far believed to be transferred from birds to humans, but it appears that the recent cases have been from possible human-to-human transmission.
More than 1,000 close contacts of those infected are under close watch for signs of the disease, according to the World Health Organization.
"We don't think there's sustained human-to-human transmission, because the only instances where there might have been human-to-human transmission are between two close family members," said WHO spokesman Gregory Hartl, explaining that the family members and neighboring children may have been exposed to the same infected bird, according to ABC news.
"The main thing now is to figure out how this virus spreads and where it lives. Until then, we're shooting in the dark," he added.
According to the Associated Press, Feng Zijian, a leading Chinese official in the government's bird flu emergency response effort said there are difficulties in gathering reliable evidence of how much contact, if any, patients have had with birds. Patients don't always have clear recollections of their recent activities, he said, while in some cases, doctors have had to rely on secondhand accounts from relatives when patients were too severely ill to answer questions.
