West Nile fever spreads to Israel's birds after causing 15 human fatalities

Israel's bird population is increasingly being infected with West Nile fever, according to the Israeli Agriculture and Food Security Ministry.

“In the past two months, 159 infected birds have been found compared to only three cases last year,” said Director of Veterinary Services Dr. Tamir Goshen in an interview with Ynet on Wednesday.

A week ago, 153 Israelis were diagnosed with West Nile fever but since then, cases have spiked and the Israeli Health Ministry now states that as many as 299 people have been affected by the virus. There have also been fatalities with 15 people dying from the disease, mostly or all elderly people.

Goshen stressed that there was no need to panic when seeing strange behavior in birds. The birds do not transmit the disease, which is spread by mosquitoes.

“We ask to be delivered the carcasses and report of deceased birds or those showcasing strange behavior,” he said. Birds do not transmit the disease, which is spread by mosquitoes.

When looking for signs of infected birds, Goshen suggested the following: “First of all, you find an abundance of bird corpses. This is the main and important thing. The second thing is seeing birds walking in circles, spinning, falling, getting up, their head turned and showing neurological indicators related to the central nervous system,” he explained.

He confirmed that any kind of bird can be infected by the virus.

“It's not just songbirds; birds of prey can also become infected via the eating of carcasses," Goshen said.

"We see birds of prey, both diurnal and nocturnal, that have been brought in and tested positive for the virus. The Agriculture Ministry, in coordination with the Health and Environmental Protection ministries, is trying to connect the dots and understand where the virus is present in the country.”

Goshen noted that the West Nile Virus strain is not a new disease and that animals had been infected in previous outbreaks.

“We saw similar outbreaks for several decades now,” Goshen noted. “There was an outbreak that severely affected humans in the late 1990s, with several dozen deaths which also severely affected horses. We haven't had cases in horses this year.”  

West Nile fever is a mild, seasonal disease, with cases typically appearing in Israel and other warm countries between June and November, when temperatures are high with high levels of humidity, creating optimal breeding conditions for mosquitos.

Common symptoms of the disease include fever, diarrhea, muscle pain, headache and general weakness, however, according to the Health Ministry, 80% of the patients do not experience any symptoms when infected. The incubation time is between 7 and 14 days and like most illnesses, individuals with a weak immune system or in poor health are at a greater risk of death.

About 1% of the cases are severe and could lead to neurological complications. Unlike the COVID pandemic, West Nile fever is not contagious.