A 76-year-old woman from Prat de Llobregat was admitted to the Bellvitge hospital this September for an illness that, pending confirmation of the diagnosis, is attributed to the West Nile virus. As a result of this case, screening for the virus has begun in all blood donations in Catalonia to prevent them from transmitting the infection.
In addition, “all healthcare centers, both primary and hospital, have been alerted to be alert to detect new possible cases,” a spokesperson for the Health Department reported yesterday.
The patient, who required admission to the ICU, is “currently in a social health center in the process of recovery, given that, beyond the infection, her health status is delicate,” Salut reported.
West Nile virus is transmitted through the bites of mosquitoes that have acquired the infection from a bird. It is not transmitted from person to person except through donations, so it is ruled out that it could cause an epidemic. It is also not transmitted from one person to another through mosquitoes. When a person is infected, the virus has first passed from a bird to a mosquito and then from the mosquito to the person.
The virus, originally from sub-Saharan Africa, is already endemic in bird populations in Catalonia. In addition, climate change favors the increase in populations of mosquitoes that can transmit it, of the Culex genus. Therefore, the number of cases in people is expected to increase in the coming years, especially in late summer and early autumn, following the annual cycle of activity of Culex mosquitoes.
The first two cases diagnosed in Catalonia, which were not related to each other, were reported in Reus in September of last year. The one that has now been detected in Bellvitge is the third that is made known. Even so, the real number of infections must be higher, since the vast majority are not diagnosed.
“The case is currently declared probable due to the difficulty of making the definitive diagnosis,” Salut reported. “We have not yet received results from the Carlos III Health Institute,” where samples from the patient have been sent to confirm the diagnosis.
80% of West Nile virus infections are asymptomatic, so they go undetected. The other 20% cause so-called West Nile fever, which is characterized by an abrupt onset of symptoms. Symptoms may include high fever, headache, muscle pain, eye pain, rash, and vomiting.
In the most serious cases, the virus infects the nervous system and can be fatal or leave serious consequences. This occurs in one in a hundred infections (or one in twenty cases with fever).
Given the evidence that the West Nile virus is already endemic in Catalonia, and the strong suspicion that the woman admitted to Bellvitge has contracted it, screening for the virus has begun in all donations. The measure was already applied last year when the first two cases were detected in Reus, but on that occasion the screening was limited to three regions.
In addition, an investigation has been carried out on the mosquitoes present in the area where the patient resides and a treatment with larvicides has been applied.
Neighbors in the area have received information leaflets by mail about the measures they can take to prevent the proliferation of mosquitoes, which is considered the best prevention strategy. The main recommendation is to prevent mosquitoes from finding stagnant waters that serve as breeding sites.
