根據一項最新研究發現，限制來自流感嚴重爆發國家的空中旅行，并不能夠防止感染的傳播。

英國健康防護署感染中心(HPA, London, UK)的研究人員，研發了一個異質群種模型，該模型由一系列相互關聯的動力學流行傳播模型組成，使用了目前已知的流感病毒傳播信息，特別是1968-1969年期間全球范圍內流感大流行的資料。聯系來自國際航空運輸協會(IATA, Montreal, Canada)2002年在105個城市之間的資料進行估計，包括100個最高的國際旅客 數量和所有的1968-1969流行期間的所有52個航班資料。根據數學模型設計，在一臺計算機上進行了疾病流行的虛擬實驗。研究人員試圖尋找病毒如何從一個城市傳播到另外一個城市，以及旅行限制是否能夠減少傳播率。

研究人員得出結論說空中旅行的限制所起到的作用甚小。這或許是因為，與其它病毒相比較，流感病毒在人之間傳播速度非常之快，而且會影響大多數人。一旦流行爆發，限制感染城市的航班，只有在發現流行之后所有城市之間的旅行被杜絕，才能有效的延緩世界范圍內的大流行。這些研究結果發表在2006年6月期的《PLoS醫學》之上。
 
Restricting Air Travel Cannot Stop Flu Pandemic
 
By medinews.com staff writers
Posted on 22 May 2006 
 
Restricting air travel from countries where there is a serious influenza outbreak will do little to hold back the spread of the infection, according to the findings of a new study.

Researchers at the Center for Infections, Health Protection Agency (HPA, London, UK), developed a metapopulation model that consists of a set of coupled dynamic epidemic transmission models, using information already available about how flu viruses spread, particularly information recorded during the worldwide flu outbreak in 1968-1969. Coupling between cities was estimated by using data for 2002 received from the International Air Transport Association (IATA, Montreal, Canada) on flights between 105 cities, including the 100 with the highest number of international scheduled passengers and all 52 flights used in the 1968-1969 outbreak. With the mathematical model devised, virtual experiments were carried out by simulating worldwide outbreaks on a computer. The researchers looked at how the virus might spread from one city to another and how travel restrictions might reduce the rate of spread.

The researchers concluded that restrictions on air travel would achieve very little. This is probably because, compared with some other viruses, the flu virus is transmitted from one person to another very quickly and affects many people. Once a major outbreak is under way, banning flights from affected cities would be effective at significantly delaying worldwide spread only if almost all travel between cities could be stopped almost as soon as an outbreak was detected in each city. The results were published in the June 2006 issue of PLoS Medicine.