What is West Nile virus: how it is transmitted, symptoms, vaccine, and treatment

Cases in Lazio

There has also been one death. The Ministry of Health: "The situation is being continuously monitored."

A lab worker examines trapped mosquitoes for signs of West Nile Virus and other diseases at the Orange County Mosquito and Vector Control District laboratory in Garden Grove, Calif., on June 27, 2023. A drone is the latest technology deployed by the district to attack mosquitoes developing in marshes, wetlands, large ponds and parks. Mosquitoes grow into larvae from eggs laid in water, making proliferation of the biting bugs a major concern after California's extraordinarily rainy winter. (AP Photo/Eugene Garcia)

Seven cases of West Nile virus infection have been confirmed in Lazio since the beginning of 2025, including one death. The Ministry of Health announced this, specifying that the epidemiological trend is consistent with that observed in previous years. " The Ministry of Health is constantly monitoring the situation in close collaboration with the Lazio Region and with the Istituto Superiore di Sanità, the National Blood Center, and the National Transplant Center. All measures envisaged in the 2020-2025 National Plan for Prevention, Surveillance, and Response to Arboviruses have been activated with the support of the Arbovirus Operational Group ," explained Maria Rosaria Campitiello, head of the Ministry's Prevention Department.

What is West Nile virus?

West Nile virus is transmitted to humans through the bite of infected mosquitoes , particularly those of the Culex genus. It is not transmitted from person to person by direct contact. Most infected people remain asymptomatic, but in vulnerable individuals, the infection can cause severe, even fatal, forms of the disease . The ministry urges the population to scrupulously observe prevention measures to reduce exposure to mosquito vectors: use skin repellents, wear long pants and long-sleeved shirts, especially during high-risk hours (dawn and dusk), install mosquito screens on windows, eliminate stagnant water from vases, buckets, pet bowls, and other containers, and empty and store paddling pools upright when not in use.

West Nile: How the virus is transmitted, symptoms, treatment, and vaccine

Health authorities reiterate that the surveillance system remains active and that adopting protective behaviors is essential to contain the spread of the virus during the warmer months.