The Subdirectorate General for Surveillance and Response to Public Health Emergency of Catalonia has reported two cases of West Nile virus infection, one confirmed and one possible, in two people living in the health region of Camp de Tarragona, which are progressing favourably.
Infectious diseases reappear silently, but unstoppably
West Nile fever is an infectious disease caused by a virus of the Flavivirus family, to which the Japanese encephalitis virus also belongs. It is a zoonosis, that is, a disease that is transmitted from animals to humans, usually by the bite of a common mosquito.
As reported by the Department of Health, after the detection of these cases, and as established by the protocol, they have carried out an entomological inspection to determine the presence, or not, of mosquito vectors in the places where they may have been. the people affected, of whom they have not provided details to preserve their privacy.
Health has recalled that the process to confirm suspected cases of Nile fever, the first of which appeared on August 31, requires microbiology and sequencing studies that are not immediate, that is why only one of the two cases is confirmed and the other is "probable", although in both the clinical evolution "is favourable".
According to the Department of Health, possible mosquito breeding sites have been searched for and inactivated in the area and adult mosquito traps have been installed to analyze the presence of the virus. Likewise, they have reinforced surveillance of other possible larval foci, especially in the areas of influence of the two cases.
The Animal Health Prevention Service is also intensifying the usual activities to detect the possible presence of viruses in birds and horses in the areas frequented by the two infected people. In addition, the Blood and Tissue Bank of Catalonia, as a security measure, is analyzing all samples from donors in the area of the two infections to detect the virus.
Health has recalled that the main route of transmission of the disease to people and animals is through the bite of mosquitoes after having bitten infected birds.
Of the forty species of mosquitoes that can act as transmitters of this disease, in Catalonia the main vector is the common mosquito (Culex pipiens).
Catalonia has a surveillance and control protocol for West Nile fever, with the participation of different departments, entities and institutions, which provides for a set of activities to monitor the disease, aimed at vector control of mosquitoes and virological surveillance in animals - wild birds, resident birds and equids.
Surveillance of the presence of the virus in humans is done through mandatory notification of the disease, hospital surveillance for active investigation of cases (surveillance of non-typed viral meningoencephalitis) and screening for this virus in blood samples of patients. donors.