Tropical Disease Unit, UHN-Toronto General Hospital, Toronto, ON, M5G 2C4 Canada.
J Travel Med. 2012 Jan-Feb;19(1):4-8. doi: 10.1111/j.1708-8305.2011.00579.x. Epub 2011 Dec 8.
Influenza is a common vaccine-preventable disease among international travelers, but few data exist to guide use of reciprocal hemisphere or out-of-season vaccines.
We analyzed records of ill-returned travelers in the GeoSentinel Surveillance Network to determine latitudinal travel patterns in those who acquired influenza abroad.
Among 37,542 ill-returned travelers analyzed, 59 were diagnosed with influenza A and 11 with influenza B. Half of travelers from temperate regions to the tropics departed outside influenza season. Twelve travelers crossed hemispheres from one temperate region to another, five during influenza season. Ten of 12 travelers (83%) with influenza who crossed hemispheres were managed as inpatients. Proportionate morbidity estimates for influenza A acquisition were highest for travel to the East-Southeast Asian influenza circulation network with 6.13 (95% CI 4.5-8.2) cases per 1000 ill-returned travelers, a sevenfold increased proportionate morbidity compared to travel outside the network.
Alternate hemisphere and out-of-season influenza vaccine availability may benefit a small proportion of travelers. Proportionate morbidity estimates by region of travel can inform pre-travel consultation and emphasize the ease of acquisition of infections such as influenza during travel.
流感是国际旅行者中常见的可通过疫苗预防的疾病，但很少有数据可以指导使用对向半球或非流行季节的疫苗。
我们分析了 GeoSentinel 监测网络中患病返回旅行者的记录，以确定在国外感染流感的旅行者的纬度旅行模式。
在分析的 37542 名患病返回旅行者中，有 59 人被诊断患有甲型流感，11 人患有乙型流感。一半来自温带地区到热带地区的旅行者在流感季节以外出发。有 12 名旅行者从一个温带地区跨越到另一个温带地区，其中 5 人在流感季节。在跨越半球的 12 名流感旅行者中，有 10 人（83%）作为住院患者进行了管理。前往东南亚东部流感传播网络的旅行者中甲型流感发病率的估计比例最高，每 1000 名患病返回旅行者中有 6.13 例（95%CI 4.5-8.2），与不在网络外旅行相比，发病率的比例增加了 7 倍。
替代半球和非流行季节的流感疫苗可能对一小部分旅行者有益。按旅行地区计算的发病率估计可以为旅行前咨询提供信息，并强调在旅行期间很容易感染流感等感染。
