Set up the alert for West Nile virus infections in Italy. Cases have in fact increased by 53% in seven days, reaching 144, and the death toll is also heavier, with 11 deaths from June to 12 August. A pathology, which is spreading especially in northern Italy, which the Ministry of Health monitors carefully but which, however, infectious disease specialists warn, rarely leads to serious consequences. Two elderly people in the Mantua area, one is in a coma.
When it was isolated
The virus is part of the Flaviviridae family and was isolated for the first time in 1937 in Uganda, precisely in the West Nile district. It is widespread in Africa, Western Asia, Europe, Australia and America. But in recent years it has also been circulating in Italy, especially in the North. Most of the infected people – explains the ISS site – do not show any symptoms. Among the symptomatic cases, about 20% present mild symptoms such as fever, headache, nausea, vomiting, skin rashes. The most severe symptoms occur on average in less than 1% of infected people, usually the elderly or debilitated, and include high fever, severe headaches, muscle weakness, disorientation, tremors, visual disturbances, numbness, seizures, up to paralysis and coma.
It is not transmitted from person to person
West Nile fever is not spread from person to person through contact with infected people. The virus also infects other mammals, especially horses, but in some cases also dogs, cats, rabbits. The incubation period from the moment of the infected mosquito bite varies between 2 and 14 days, but it can be as long as 21 days in subjects with deficiency in the immune system. Diagnosis is mainly carried out through laboratory tests (Elisa or Immunofluorescence) carried out on serum and, where indicated, on cerebrospinal fluid, for the search for IgM antibodies. There is no vaccine for West Nile fever. Currently vaccines are being studied, but for the moment – explains the ISS – prevention consists above all in reducing exposure to mosquito bites. There is also no specific therapy. In most cases, the symptoms go away on their own after a few days or can last for a few weeks. In severe cases, hospitalization is instead required, where the treatments administered include intravenous fluids and assisted breathing.
The progression of cases
According to data from the Surveillance on West Nile and Usutu virus, carried out by the Higher Institute of Health, 144 infections were reported from the beginning of June until last August 9, 50 more than 7 days ago with an increase of 53% . Four deaths in the last week, bringing the toll from the start of the season to 11 deaths: 6 in Veneto, 2 in Piedmont, 2 in Lombardy and 1 in Emilia-Romagna. The latest death occurred today. It is a man from Brescia. He was one of the two most serious patients of the four Brescia cases and was hospitalized.
Presence in animals
Among the 144 cases of West Nile virus infections in humans, 87 experienced neuro-invasive symptoms, 33 fever, 23 cases were identified in blood donors. Surveillance also confirmed the presence of the virus in animals: 121 pools of mosquitoes captured in Friuli Venezia Giulia, Veneto, Piedmont Emilia Romagna and Lombardy tested positive for the virus. 41 positive birds and 6 equid outbreaks were also identified. However, no positivity was found for West Nile in poultry farms.