Via The New York Times: Rise in Bird Flu Cases in China Stokes Worry Before Peak Travel Time. Excerpt:
The increased tempo of cases comes just before people across China begin their traditional trips to family reunions for celebrations of the Chinese New Year, which falls on Jan. 31 this year. The official travel season in China began Thursday, with the government estimating that 3.62 billion trips would be taken in the next 40 days by road, train, airplane and other modes of transportation.
Many of those trips are to hometowns in rural areas. A large majority of today’s Chinese grew up in the countryside, even though the country as a whole became more than 50 percent urban in 2011 because of heavy migration to factories, construction sites and universities in cities.
Contact with poultry, common in rural areas, is still the main route of infection for the virus. Heavy travel in densely packed vehicles offers the virus more chances to pass from person to person, and possibly evolve into new forms that may be more readily transmissible.
In a sign that governments around the region are starting to take precautions as well, Hong Kong announced late Friday that it would begin conducting blood tests on Jan. 24 on local and imported poultry to determine if they have the virus. Any birds with confirmed infections will be killed, as will any birds that have been kept with the infected birds, said Dr. Ko Wing-man, the secretary for food and health.
Health experts are watching closely for two warning signs of greater human-to-human transmission that have not yet occurred on a large scale.
One sign would be a spate of cases among people who have had no apparent contact with poultry or environments contaminated by the feces, uncooked blood or other fluids of poultry. The other would be a series of cases in which several members of the same family fall ill in quick succession and appear to have transmitted the disease to one another.
Helen Yu, a spokeswoman for the Beijing office of the World Health Organization, wrote in an email that the proportion of cases among people who had no contact with poultry had stayed low since the disease emerged nearly a year ago and showed no sign of increasing this winter.
Similarly, there has been only one family cluster of cases this winter, compared with four clusters last spring.
“It is possible that limited human-to-human transmission may occur, but there is no evidence of sustained or widespread human-to-human transmission,” she wrote. “We continue to expect sporadic human cases.”