The heat accelerates times, and cases of West Nile (West Nile disease) are multiplying in Italy, causing concern in the heart of the Po Valley and in Sicily. A situation in which the disastrous floods that hit Emilia Romagna only make things worse from the point of view of public health. So much so that the Higher Institute of Health takes a position right on the West Nile: in these days it has published the first bulletin of the 2023 season, a bulletin which, as evidence of the acceleration of the virus, starts not from June but from May 2023. The report highlights confirmed positivity of West Nile Virus WNV in two Provinces: Catania (04/05/2023) and Varese (08/05/2023), but only in animal populations, therefore not currently in humans.
West Nile, transmission and symptoms: how we can defend ourselves
In the viewfinder Catania and Varese
Going into the merits, the National Reference Center for the study and assessment of exotic animal diseases (Cesme) of the Experimental Zooprophylactic Institute of Abruzzo and Molise, found WNV in a group of mosquitoes caught in Sicily, in province of Catania, and in a crow belonging to a target species in the province of Varese. No cases, however, have so far emerged among equids, wild birds, and poultry farms. This means that, at least at this time, the virus has not affected humans. Nonetheless, experts are paying particular attention to the evolution of the situation.
The record reached in 2022
After all, it is enough to look at last year to realize that all fears cannot be allayed. 2022 marked an increasing number of cases in Italy, very high compared to the rest of Europe, second only to those of 2018, the year which, also in Italy, recorded an unprecedented boom in outbreaks, exceeding the entire European area. From early June to early November 2022, 588 confirmed cases of West Nile Virus infection in humans were reported nationwide.
A situation which, framed on European territory, gives an idea of the anomaly we are experiencing, apparently directly linked to climate change. According to the ECDC (European Center for Disease Prevention and Control), as of 26 October 2022, a total of 949 cases had been registered in Europe, of which 573 in Italy, 283 in Greece, 46 in Romania, 14 in Hungary, 9 in Germany, 8 in Croatia, 6 in Austria, 5 in Spain, 4 in France and 1 in Slovakia. Among these, 72 deaths occurred, of which 37 in Italy, 30 in Greece and 5 in Romania.
How West Nile broadcasts
But how is the virus transmitted? Isolated for the first time in 1937 in Uganda, precisely in the West Nile district (from which it takes its name), its main vehicle of transmission is wild birds and mosquito bites (most frequently of the Culex type). Other documented means of infection, although much rarer, are organ transplants, blood transfusions and mother-to-fetus transmission during pregnancy.
Although West Nile disease is not transmitted from person to person, the virus can infect other mammals, such as horses, dogs, cats and rabbits, inevitably putting humans at risk as well.
West Nile virus, a mosquito tracking app
Symptoms and how to avoid it
Coming to the symptoms, the most serious ones occur on average in less than 1% of infected people (one in 150), and include high fever, severe headaches, muscle weakness, disorientation, tremors, vision disturbances, numbness, convulsions , up to paralysis and coma.
So what to do to not get infected? The most effective preventive method consists in avoiding mosquito bites, through the use of skin repellents and staying as much as possible in environments protected by mosquito nets and/or equipped with insecticide diffusers for domestic use.