The West nile or western Nile fevera disease with an exotic name that in the past was actually considered only one of the many tropical diseases, today in Italy it is no longer just an occasionally imported phenomenon, but one endemic disease. Thanks to the fact that some species of birds are virus tanks and in several cases infections have also been found in horses and dogs. This was confirmed by the many cases recorded in different areas of the country, with a cluster of native cases in the province of Latina, in Lazio, and the death of an 82 -year -old woman residing in Nerola (Rome) and hospitalized for fever and confusion at the San Giovanni di Dio hospital in Fondi (Latina), who have aroused particular attention.
The role of the climate
“Climate change also plays a central role in the increased circulation of this virus. L‘Raise of temperatures and the “Tropicalization ”of Italian cities They create favorable conditions for the proliferation of carrier mosquitoes, thus extending the risk of infection to new areas of the country. At the moment, I wouldn’t talk about alarm But it is certainly a situation that deserves a huge attention both by the health personnel and by the institutions as well as citizens “
Report Fabrizio Pregliasco, virologist and professor of General Hygiene and Applied at the University of Milan, scientific director of Observatory Virusirespiratori.it.
Who risks more
It is infectious disease transmitted to man from mosquito puncture (more frequently of the Culex type) and is not transmitted from person to person. Most of the people infected with the virus do not show symptoms or get sick slightly: only 20% have light disorders such as fever, headache, nausea, vomiting, enlarged lymph nodes, skin rates. In the elderly and in immunosuppressed people, however, the symptomatology can be more serious and also affect the central nervous system with forms of meningitis or encephalitis, which can also be fatal.
“At the moment there are no vaccines or medicines that specifically deal with the virus. The only way to protect yourself from the West Nile is therefore prevention, that is, to reduce exposure to mosquito stings. In this regard, therefore, fundamental are the individual protective measureslike the use of repellents and mosquito nets, together with the disinfestation of green areas and the removal of water stagnation where the mosquitoes reproduce; Also because the mosquitoes can transmit not only the West Nile but also other dangerous viruses such as the Dengue, the Chikungunya, the Zika Virus, the usutu virus, malaria and other vector transmission diseases “
explains Pregliasco.
How to deal with the infection from West Nile Virus
The disease in humans has an average incubation varying from five days to two weeks and can have very different manifestations from case to case. In most cases they start as a very common Fluish syndromewith fever, headache and muscle pain that tend to go by themselves in a few days. Quite common is also the interest of the lymphatic glandsas well as localized redness of the skin may be present. Only in some people, and they are above all the elderly, the infection can determine encephalitiswhich can be fatal or even leave as a “inheritance” of the contact with the virus neurological problems.
In these cases the clinical picture is very different: they can in fact be present A very strong headache, the rigidity of the neck similar to that of meningitis, muscle weakness and loss of consciousness. There fever It is almost always very high and remains such for several days. However, it is a globally uncommon picture, if you think that according to some statistics less than one in one hundred among those who are infected, the encephalitis develops. On the care front, there is no specific antiviral treatment.
The hospitalization It is essential in forms with encephalitis, because it is necessary to support breathing, ensure adequate nutrition and prevent secondary infections, perhaps caused by potentially fatal bacteria. In a preventive key, unfortunately There is still no specific vaccine.
The characteristics of the virus
The disease has a variable average incubation from five days to two weeks. And linked to a virus of the family of flavivirus. Among the characteristics of these strains there is one that particularly worries. Are particularly brought to attack the central nervous systemand in particular the brain. In particular, this particular kind of virus is a single filament RNA: it is protected by a sort of “membrane” (capside) surrounded by a pericapside in its sola. The flavivirus family includes several causal agents of diseases, starting from the yellow fever to get to the Dengue and different types of encephalitislike Japanese encephalitis.
The role of mosquitoes
The transmission of the virus sees mosquitoes as vectors, given that the pathological agent passes to humans and other animals such as horses through the sting of the mosquito. The “enemy” can be spread above all through migratory birdswhich are precisely points from the insects and get the virus inside them. Once points from the mosquito, these animals can then release the virus that is transmitted to a new guest. Mosquitoes are infected when they come into contact with infected birds that can circulate the virus in their blood For a few days. Infected mosquitoes can therefore transmit the western Nile virus to humans and animals, which are therefore terminal guests while they puncture to take blood. The virus is located in the salivary glands of the mosquito. While they suck the blood, The virus can be injected into the animal or in humanswhere it can multiply, and therefore can cause the disease. The animal’s contagion does not take place. Intermane transmission, in theory, could only occur in a few cases, such as after an organ transplant.
