Avian Flu (N7N9) Makes Leap from Bird to Man


Do you remember the ” target=”_blank”>a review of the public health findings thus far.

The review stated that up to now 82 people have been confirmed to have H7N9 in 6 different regions of China. Most of them were extremely ill, but that is largely because of the way in which they were identified – patients with severe respiratory illness were tested for the virus. Of these 82 patients, 17 have died (21%) and 60 remain critically ill. The incubation period ranged from 1 to 10 days, and those who died were ill for a median of 11 days.

Four of the patients were poultry workers and 77% had known exposure to live animals, mostly chickens. This suggests that the majority of the cases are due to transmission from birds to humans. There were no confirmed cases of human to human transmission but in two families human to human transmission could not be ruled out.

The concern is that eventually, through random mutations, H7N9 will get better at human to human transmission. Then, as in the swine flu epidemic of 2009, since the entire human population has never been exposed to H7N9, we will be a very large non-immune target. Like the first spark in a forest that hasn’t burned in many decades, very rapid spread would be likely.

Yesterday ” target=”_blank”>Preliminary Report: Epidemiology of the Avian Influenza A (H7N9) Outbreak in China (NEJM)
” target=”_blank”>China's H7N9 bird flu death toll likely to rise (Los Angeles Times)