Twelve middle aged and elderly Israelis have died since August of complications of the mosquito borne disease West Nile virus, and an additional 157 have survived it. Between August and October 1999 in New York city more than 66 people were infected and six died.
The Israeli health ministry's associate director general, Dr Boaz Lev, had initially claimed that the high numbers were due to sophisticated laboratory tests first made available here last year that enabled the government to screen the blood of people complaining of symptoms.
As the numbers mounted, they conceded, however, that there was a genuine outbreak, and some experts in infectious diseases called it an epidemic. The West Nile virus is harmless in healthy people but can cause fatal inflammations of the brain and spinal cord in immune compromised or immune suppressed patients.
The youngest Israeli who died of the disease was a 54 year old woman who had myasthenia gravis; she was bitten by an infected mosquito and died of encephalitis. But most of the others were aged over 80 and had chronic diseases of old age.
The health ministry in Jerusalem was slow to wake up to the danger, apparently hoping in August that it would just blow over. This was despite the fact that New York health authorities had informed them last year that the viral strains they had isolated in the United States were closely similar to or identical with those found in Israel. They suggested that infected pet birds may have been smuggled from Israel to the United States and been responsible for the New York outbreak.
Panic is spreading, and hospital emergency rooms around the country are filling up with anxious healthy people bitten by mosquitoes or with mild flu-like symptoms.
Meanwhile, intensive pesticide spraying has been carried out at night, especially in the hardest hit area, around Sharon, north east of Tel Aviv. Environmentalists are worried that this “cure” might in the long term be worse than the disease itself.
As Israel is one of the world's major stopovers for migrating birds in the autumn and spring, millions of them will be passing through nature reserves in the coming weeks, and some could be bearing West Nile virus.
Although Professor Manfred Green, head of the Israel Center for Disease Control, predicts that the outbreak will stop with the imminent colder weather and rainy season, others worry that Israel's winter temperatures might not be low enough to kill off all the mosquitoes.
Most Israelis have natural immunity to West Nile fever, which was first reported in Uganda in 1937; its ecology was characterised in Egypt in the 1950s, and an outbreak of meningoencephalitis (inflammation of the spinal cord and brain), affecting 400 people, was reported in Israel in 1957. It has since become endemic in the Middle East and Africa and has spread to Europe, central Asia, Oceania, and, most recently, North America.
Although mosquitoes bearing the flaviviridae family virus have usually contracted it by biting infected poultry (especially geese) and other birds, scientists have isolated the virus in mammals such as cats, dogs, and horses.
Figure.
AP PHOTO/PAVEL WOLBERG
An Israeli municipal worker sprays anti-mosquito dust