Health authorities are reporting a marked increase in cases of West Nile Virus (WNV) infections in many countries in Europe. Outbreaks are occurring in Croatia, Italy, Romania, Kosovo and Istanbul, Turkey.
WNV is a viral illness transmitted by the bite of an infected mosquito. Most infections produce no symptoms, but severe cases can involve the nervous system, resulting in severe disability and death. One clinical case of WNV often represents 10 or more asymptomatic infections in the population.
West Nile Virus also occurs in the United States. The U.S. CDC reports 976 WNV cases across 46 states in the U.S. so far in 2024 (as of Oct. 8) with 684 of those classified as “neuroinvasive”. In 2021, Maricopa County experienced one of the most severe and concentrated WNV outbreaks in the world. That year, the county reported 1480 human cases and 101 deaths, with cases in Scottsdale outnumbering the rest of the county 5 to 1.
There are no vaccines or medications available to prevent or treat WNV. Travelers to areas with increased WNV activity should observe careful insect bite precautions. Mosquitoes that transmit WNV are generally night biters but have peak activity at dusk and again at dawn.
