The Generalitat of Catalonia has activated level 2 surveillance of diseases transmitted by mosquitoes after identifying on a horse sick of an equestrian in Vilanova i la Geltrú (Barcelona) the West Nile fever virus, as confirmed by the departments of Health and Farming. It is the first time that the virus, which naturally circulates between birds and mosquitoes, jumps to other species in Catalonia, in a new step of the important expansion that the disease lives this year in Europe.
"This diagnosis is important because it reveals the presence of the virus in an area until an hour free of the disease. It has already reached Catalonia and, as in other places, if he has come is to stay ", illustrates Miguel Ángel Clavero, scientist of the National Institute of Agricultural and Food Research and Technology. "Last year was detected in a bird in Lleida, but this is the first time that the jump to horses or humans occurs, the species most vulnerable to the transmission of the virus through mosquito bites," he adds.
Nile fever is a generally very mild disease in people: in four out of five cases it occurs asymptomatically. In the rest, after an incubation that goes from three to 14 days, the patient suffers fever, malaise, body aches and fatigue. The most severe cases, 1% of the total, cause episodes of encephalitis and meningitis. At this level, the lethality of the disease is 10%, especially in children and the elderly. There is no vaccine or specific treatment against the virus and the care focuses on the symptoms and complications.
The European Union suffers this year the largest outbreak of Nile fever since records exist, with more than 1,400 patients of concern and 127 deaths, according to data from the European Center for Disease Control and Prevention (ECDC, acronym in Spanish). English). Although most cases have occurred in Italy and countries in the Balkan area, in recent weeks there has been an increase in the incidence in Western Europe. France, for example, reported last week the first case in humans in the Department of the Eastern Pyrenees, just north of Catalonia.
The notice of this case came to the Generalitat last 11th and has been confirmed in recent days by analyzes carried out by both the Catalan Government and the national reference laboratory, located in Algete (Madrid). The technicians displaced to the equestrian test proved the existence of several outbreaks of mosquitoes both on the farm and in the surroundings, which have already been duly neutralized. Some of them were Culex pipiens, the mosquito species that acts as the most important vector of the virus. In coordination with the Municipality of Vilanova i la Geltrú, the Generalitat has provided those responsible for the surrounding land with the necessary training to combat the proliferation of mosquitoes.
Andalusia registered the first case in horses of the year in Almonte (Huelva) two weeks ago. "There the outbreak was predictable. We have documented the presence of the virus in Western Andalusia since 2004 and in recent years there have been sporadic outbreaks in both horses and humans. The surprise has now been the diagnosis in Catalonia, "reiterates Clavero. For this expert, although in the next few weeks there may be another case, an outbreak of the disease is not foreseeable. "We are at the end of the season, with the decrease in temperatures, the proliferation of mosquitoes is interrupted and, with that, the risk of contagion," Clavero concludes.