West Nile virus: 11 deaths in Italy to date. First case of infection in Biella. Insects tested positive in Isernia.

The first case of West Nile fever has been confirmed in the province of Biella by the local health authority: a woman hospitalized at Degli Infermi Hospital was diagnosed with West Nile virus.

The 72-year-old patient, a resident of the lower Biella area, is debilitated due to other comorbid conditions. "Despite her general frailty and need for assistance, she has been slowly improving since her arrival at the hospital and is responding to the antiviral and supportive treatments provided," the ASL statement reads.

To date, the most affected areas are Lazio and Campania. The most recent bulletin from the National Institute of Health (ISS) reports 11 confirmed victims, dated August 7 .

Two days ago, the Lazio Region announced that it had extended its West Nile virus prevention and containment measures to the Rome area , managed by the ASL RM3. Containment in the area was made necessary after a case was detected in a 77-year-old woman with possible exposure in the Infernetto area of Rome .

The woman is hospitalized in a regular ward at the Spallanzani Hospital . The decision was made during a meeting held yesterday with the Lazio Region, the Regional Directorate for Health and Social-Health Integration, the Lazzaro Spallanzani National Institute for Infectious Diseases, and the Experimental Zooprophylactic Institute of Lazio and Tuscany, as well as the Health Authority itself. That evening, a meeting was held at the Capitoline Hill to support the regional committee coordinating virus prevention and control efforts. The meeting was attended by the Mayor of Rome Roberto Gualtieri, the Environment Councilor Sabrina Alfonsi, the Social Policies Councilor Barbara Funari, the AMA (Italian Association of Emergency Medical Services), the Local Police, and the Civil Protection Department of Rome.

Two deaths in just a few hours in Lazio, bringing the total to seven. One is an 83-year-old woman from Pontinia , who died at the Santa Maria Goretti Hospital in Latina. The woman had arrived at the emergency room on July 24th. Admitted to intensive care in serious condition due to multiple comorbidities, she died in the intensive care unit. The seventh victim in the region is a 77-year-old man who died at the Isola Tiberina Gemelli Isola Hospital. Already undergoing dialysis, he had been hospitalized in intensive care since July 26th. He was a resident of Velletri and was exposed to the virus in Cisterna di Latina .

Several cases of West Nile mosquitoes have been recorded in the province of Sernia. Therefore, the Molise Regional Health Authority has implemented all the measures required in such cases, starting with safety measures for blood transfusions.

"As recommended by the National Blood Center," Asrem explains, trying to dispel alarmism, "it is recommended to test donors or, alternatively, temporarily suspend blood donations for 28 days for those who have spent at least one night in the province of Isernia." Furthermore, Dr. Carmen Montanaro, director of Asrem's Single Prevention Department, specifies, "given the epidemiological situation, the mayors of the province of Isernia have been asked to implement all the strategies set out in the National Arbovirus Plan, and in particular, to carry out disinfestation with adulticide treatments within their municipal areas, using authorized and specialized companies."

An 80-year-old man from Riace died at the Reggio Calabria Hospital, where he had been admitted to the infectious diseases ward for encephalitis a few days ago. After his admission, doctors confirmed he had a West Nile virus infection. Following his death, Riace Mayor Mimmo Lucano ordered a disinfection program throughout the municipality.

The Novara Local Health Authority (ASL) has detected two cases of West Nile virus infection in the capital. These are two elderly people living in different areas of the city. One of the two cases did not require hospitalization, despite a high fever. The other case, which developed in the last few hours, is in a more complex situation. The infected person was hospitalized. His condition is stable, although the presence of other medical conditions requires close monitoring.

According to the local health authority (ASL), the two patients had not traveled recently and therefore contracted the virus in an urban setting. In Novara and the surrounding province, six people who contracted the virus have died in recent years. The last case dates back to last March, when a 75-year-old man living in Vespolate, in the lower Novara area, died.

According to the report of the European Centres for Disease Prevention and Control updated to July 30 "From the beginning of 2025 to July 30, five countries in Europe have reported human cases of West Nile virus infection: Bulgaria, France, Greece, Italy, and Romania."

The report includes confirmed and probable cases, specifying that the counts "are preliminary and should be interpreted with caution, as they may be revised by countries as more information becomes available. Therefore, totals are not provided." Looking at the table, however, Italy has recorded the highest number of infections, followed at a distance by Greece, Romania, Bulgaria, and France. And the ECDC specifies that "the highest number of cases was reported in the province of Latina," in Lazio.

It is an infectious disease transmitted by mosquitoes , particularly those of the Culex pipiens genus , which primarily affects wild birds. Mosquitoes become infected by biting birds and sometimes transmit the virus to accidental hosts such as horses and humans. The mosquito that transmits West Nile virus is not the tiger mosquito, but rather our nocturnal common mosquito, which bites from dusk to dawn. Other possible transmission routes include blood transfusions and organ transplants from infected donors, and even more rarely, congenital infections transmitted from mother to fetus through human milk have been reported.

Most infected people show no symptoms . Of those who do show symptoms, about 20% experience mild symptoms such as fever, headache, nausea, vomiting, swollen lymph nodes, and skin rashes. These symptoms can last a few days, or in rare cases, a few weeks, and can vary greatly depending on the person's age.

A mild fever is more common in children, while symptoms in young people include moderately high fever, red eyes, headache, and muscle aches. In the elderly and debilitated, however, symptoms can be more severe. The most severe symptoms occur in an average of less than 1% of infected people (1 in 150) and include high fever, severe headache, muscle weakness, disorientation, tremors, vision changes, numbness, convulsions, and even paralysis and coma. Some neurological effects may be permanent.

West Nile fever, like dengue, "is a disease caused by a virus" carried by mosquitoes, although "the dynamics of diffusion are different. While for dengue the cycle is human-tiger mosquito-human, for West Nile the reservoirs are birds and the vector is the common mosquito that infects humans by biting them.

In this context, crows and seagulls in cities could influence the epidemiology of some infectious diseases, including West Nile . Fortunately, for now, no problems have been found in cities, and it's not a given that they ever will," explains Gianni Rezza, former director of Prevention at the Ministry of Health and now associate professor of Hygiene at Vita-Salute San Raffaele University.

But how will West Nile evolve this summer in our country? "National data," Rezza emphasized on social media, "do not show an excess of cases compared to previous years, but there is evidence of an expansion of the outbreaks, which this year, at least for now, are more active in some areas of central and southern Italy (provinces of Latina, Anzio/Nettuno, and Caserta) than in the Po Valley. Historical data from recent years show an increase in cases in August and then a decreasing trend starting in September. This isn't a rule, but it's what we've consistently observed, and it's not a given that it will be repeated (for better or worse) this summer, given climate change and the anticipated heatwaves."