Study points out areas at risk for H7N9 virus

The H7N9 bird flu virus, which has caused severe illness and deaths in China, may inhabit only a fraction of its potential range and could possibly spread to India, Bangladesh, Vietnam, Indonesia and the Philippines, according to a study published in the latest issue of the journal Nature Communications.

The emergence and spread of the disease has been linked until now mainly with areas that have a high concentration of markets selling live birds, but it does not appear related to China's growing number of intensive commercial poultry operations, it found.

An H7N9 "risk map" has been developed showing where human infections - so far caused mainly by contact with birds and not through human-to-human transmission - might occur next.