Recurrent West Nile virus outbreak in the United States in 2022: Current challenges and recommendations

Abstract

West Nile virus (WNV) has afflicted various countries around the world, affecting not only humans but also non-human animals, such as horses and birds. WNV is an arbovirus that is transmitted to humans by mosquito bites. The WNV epidemic was initially localized to Africa, Asia, Europe, and the Middle East. An outbreak of WNV recently occurred in the United States (US), and is currently ongoing. This article aims to elucidate the trajectory of this ongoing outbreak in the US to inform efforts to control the recurring infection. As of November 15, 2022, the Centers for Disease Control and Prevention (CDC) has reported 913 cases of WNV in humans in the US, of which 639 (70%) were categorized as neuroinvasive and 274 (30%) were categorized as non-neuroinvasive disease. Health authorities should swiftly act before WNV reaches a severe level, to prevent aggravation of existing challenges amidst the coronavirus disease 2019 and monkeypox pandemics in the US. Decreasing breeding habitats, ongoing surveillance of mosquito larvae, biological and microbial larval control methods (fish and copepods), chemical control methods (larvicides), controlling adult mosquito vector populations (hot or cold aerosols), and active practice of community-based preventive measures may avoid widespread outbreaks of WNV in the US. This brief article discusses the ongoing outbreak of WNV in the US, and highlights epidemiological and preventive measures related to WNV infection.