We have identified you may not be viewing TRAVAX optimally because the browser you are using is unsupported - click here.
We have identified you may not be viewing TRAVAX optimally because the browser you are using is unsupported - click here.
In recent weeks Health Departments across the United States of America have begun reporting the detection of West Nile virus in mosquitoes. A small number of human and animal cases have also been reported. Many health departments are now reminding locals to practice bite-avoidance to reduce risk of being infected. States reporting infected mosquitoes are across the United States from California in the West to Pennsylvania in the East, and Minnesota in the North to Texas in the South. In 2016 CDC reported that 2038 human cases were reported in 47 states and the District of Columbia. Of these, 1140 (56%) were classified as neuroinvasive disease (e.g. meningitis or encephalitis).
Mosquito season across the USA varies depending on latitude, ranging from May-August in the north to February-November in the south: in Alaska mosquito season is short from June to July.
West Nile is caused by a Flavivirus transmitted by Culex mosquitoes which bite mainly from dusk to dawn. Most infections are asymptomatic and severe infection is rare.
West Nile Fever is rarely reported in travellers. Risk is greatest in those undertaking outdoor activities.
Advice to travellers
Travellers should avoid mosquito bites by covering up and using insect repellants when outdoors especially at dawn and dusk or when mosquitoes are biting.
Further information can be found on the West Nile Fever Page.
NOTE: WNV can also be passed on by blood transfusion, consequently blood donors that have visited a WNV risk area four months prior to donation may have their donation tested for WNV. The Scottish National Blood Transfusion Service have produced a leaflet which details information about blood donation after travel:
