the west Nile virus has been making headlines in the us for quite some time now. Till now, three people, 213 birds and 114 mosquito pools have been reported infected with the virus in different parts of the country. It is believed that the virus, which killed seven people last year, was brought into the country by migratory birds.

Though birds cannot transmit the disease, mosquitoes feeding on them can carry the virus and infect humans. Those with a weak immune system, such as children and the elderly, are at increased risk. The symptoms include severe headaches, fever and muscular disability. In acute cases, it causes encephalitis (swelling of the brain) and there is no cure, except to give the patient an intensive support therapy such as intravenous fluids, ventilators and antibiotics.

When the us Center for Disease Control and Prevention found that the virus had survived through the winters in birds and mosquitoes, they undertook a massive spraying of insecticides to kill mosquitoes. They are also using larvicides and biological control agents like bacteria to control the mosquitoes that might hatch in stagnant water bodies and storm drains.

Environmentalists, however, have protested against the massive spraying of the insecticides. "The city is taking an irresponsible course of action,' said Kimberly Flynn, a researcher at the New York Environmental Law and Justice Project. This year, the authorities are using synthetic pyrethroids