# 4212
From an epidemiological point of view, the massive human migration that surrounds the annual Chinese New Year’s celebration presents a fascinating real-time experiment in the spread of viral illnesses. Over a month’s time, hundreds of millions of trips will be made all across Asia, as people take part in Chunyun, or the Spring Festival travel season.
It is, quite rightfully, billed as the largest annual migration of humans on the planet. Chunyun begins about 15 days before the Lunar New Year and runs for about 40 days total.
While the actual date varies each year (it is based on the Lunar Calendar), Chinese New Year falls between late January and mid-February.
This year, the Lunar New year falls on February 14th, and with it comes a cultural ethic for millions who have moved to the big cities to return home to visit with their families.
These travelers will spend a few days in their home village or town, and then travel back to the city where they work or attend school.
With an influenza pandemic ongoing, this is an opportunity for the virus to hitch a ride to remote areas of China and other parts of Asia that have been relatively untouched by the illness.
The concern is - just as the flu is beginning to recede in many areas of the world - the Spring Festival travel season could reinvigorate the virus by providing it with fresh, immunologically naive hosts.
China Says H1N1 Flu Spreading Into The Countryside
January 03, 2010
BEIJING (Reuters) -- The H1N1 strain of flu is rapidly spreading into China's vast countryside and there could be a spike in cases around the Lunar New Year period when millions head back to their home towns, the Health Ministry said.
The world's most populous nation has reported 648 deaths to date from what is often called swine flu, a tiny portion of the estimated 12,220 deaths around the globe, but has launched a massive vaccination campaign.
"Outbreaks in Beijing, Shanghai, other large cities and in schools have seen an obvious decline, but the virus continues to spread into villages and communities," the Health Ministry said in a statement on its website (www.moh.gov.cn).
The government has been especially worried as the country heads into the depths of winter and ahead of the Lunar New Year holiday in February, when millions of people travel back to their home towns -- potentially taking flu with them.
"The risk of catching H1N1 will increase, and the virus prevention situation is still grim," the ministry added.
While often called `Chinese New Year’, this travel ethic encompasses much of Asia, with Korea, Vietnam, Cambodia, and Malaysia (among others) participating.
Even though the celebration is still five weeks away, preparations are underway in many countries, as evidenced by this story from the Straits Times.
Chinese New Year travel rush already on
Terrence Voon
Sun, Jan 03, 2010
The Straits TimesThe great Chinese New Year travel rush has already begun - at least for bus tickets to Malaysian towns.
Coach operators said trips across the Causeway are all but fully booked as travellers plan to take advantage of the long Chinese New Year weekend from Feb 13 to 16.
The majority of seats have been taken up by Malaysians who are making their annual sojourns home to celebrate the festival with their families, noted major operators like Grassland Express & Tours.
The most commonly available conveyance in most of Asia will be crowded busses and trains, where travelers in close proximity with each other will have a greater chance of spreading or contracting the flu.
Assuming the virus is still circulating (even at reduced levels) in the big cities a month from now, one could deduce that there is a pretty good chance H1N1 will be distributed to more remote areas of Asia during this holiday.
And along the way, H1N1 will have a greater chance of meeting up with, and possibly exchanging genetic material (reassortment) with, other flu viruses which may be in circulation in rural China.
How likely that is to happen is unknown, although it does appear to be a relatively rare occurrence.
The novel H1N1 virus, of course, is a reassorted virus which appears to have bounced around in swine for years before adapting to humans.
The 1968 and 1957 pandemic viruses are also believed to have come about due to a reassortment of flu viruses.
The etiology of the 1918 pandemic is less clear.
The most likely scenario is something far less drastic, although certainly not without serious local impact; a spike in H1N1 cases across rural areas of China and other Asian nations.
Given the sparse (oft times non-existent) surveillance and reporting in that part of the world, it may be some time before any credible analysis of the impact of this year’s travel season can be offered.
But rest assured, scientists and government officials will be watching the aftermath of this year’s Lunar New Year with great interest.
