Brazil's Ministry of Health confirmed this week the country's first recorded death from West Nile Fever: a 77 year old woman from Imbituba, in the southern state of Santa Catarina, according to reporting by DW Brasil published through Folha de S.Paulo. The case has drawn attention because the mosquito borne disease remains little known in Brazil, even as European health authorities report this year's highest number of cases and affected countries in recent memory.
According to the Ministry of Health and CNN Brasil, the woman is the second patient with West Nile Fever ever recorded in Santa Catarina. The state's first case, a 56 year old man from Cacador, has already been discharged. Two more confirmed cases come from Sao Paulo state: a 34 year old woman from Ribeirao Preto who had recently traveled to the Amazon region and has recovered, and an 18 year old from Sao Jose do Rio Preto who remains hospitalized. A sixth case, in the northeastern state of Piaui, is still under investigation. Health authorities are still tracing exactly where and how each patient was exposed to the virus, information that remains open rather than settled.
West Nile Fever is caused by an arbovirus in the same family as dengue, Zika, chikungunya and yellow fever, spread through the bite of Culex mosquitoes (common house mosquitoes), which become infected after biting wild birds that carry the virus. Humans and horses are dead end hosts, meaning they do not pass the infection on. The Ministry of Health estimates that about 20 percent of infected people develop symptoms, usually mild ones such as sudden fever, headache, muscle and eye pain, nausea and skin rash. Severe cases involving meningitis, encephalitis or acute flaccid paralysis are rare, but it was precisely a neurological presentation that marked both Santa Catarina cases, according to the state health department.
Europe also seeing a rise
The same virus is worrying health authorities in Europe, where circulation has intensified this year. According to the European Centre for Disease Prevention and Control (ECDC), cited by DW, 12 European countries have reported cases in 2026, three more than in the same period last year: Albania, Germany, Austria, Spain, France, Greece, the Netherlands, Italy, Kosovo, North Macedonia, Romania and Serbia. Italy and Greece account for the largest numbers, with 311 and 157 infections respectively. In 21 regions across the continent, this is the first time health authorities have reported the disease. As of August 5, Europe had recorded 12 deaths from the virus this year; the Netherlands, which had not seen a case since 2020, confirmed a new infection the previous week and reported an additional death this past Wednesday, according to the report.
There is no vaccine or specific antiviral treatment for West Nile Fever, according to the World Health Organization. Care is limited to managing symptoms and, in severe cases, hospital support. As a result, both in Brazil and in Europe, health authorities are focused on epidemiological surveillance and mosquito bite prevention rather than a cure or available immunization.
For the general public, the practical advice mirrors what is already recommended against dengue and other mosquito borne diseases: eliminate standing water at home and in yards, use repellent, install screens on doors and windows, and limit prolonged outdoor exposure at dusk and at night, when mosquitoes are most active. People who work in rural or forested areas, such as farmers, veterinarians and biologists, face higher exposure risk and should take extra precautions. Anyone who develops sudden high fever with severe headache, confusion or muscle weakness after mosquito bites should seek medical care promptly, since these signs can indicate neurological involvement.