NEW CITY, N.Y. (AP) _ More than 200 ailing New Yorkers have been tested this year for the potentially deadly West Nile virus, without a single positive result, the state Health Department said.

But results are pending on many more cases, including a 71-year-old South Carolina man who died Wednesday on Staten Island. And mosquito-fighting efforts intensified, with suburban Rockland County deciding to join Suffolk, Westchester and New York City in spraying insecticide.

The man who died had been in New York only two days before getting ill on July 4, and city officials said that made West Nile unlikely because it usually takes five days for symptoms to appear. But his symptoms put doctors on alert.

The virus, which killed seven people in the New York area last year, has been discovered this year in more than two dozen birds and in mosquitoes. Hospitals have been asked to send blood specimens from any patient with symptoms similar to West Nile's: muscle aches, stiff neck and flu-like symptoms. To date, of 208 people tested, all have turned up negative.

The West Nile virus, transmitted by mosquitoes, is commonly found in Africa, Eastern Europe, West Asia and the Middle East. Its appearance in the New York area was its first in the Western Hemisphere, and it prompted a massive campaign of aerial and ground spraying to kill mosquitoes.

At a conference in Atlanta on Wednesday, scientists warned that West Nile could be the first of a new generation of deadly outbreaks caused by increased world travel.

They said only intense cooperation among public health officials, hospitals, veterinarians and the media kept West Nile from being exponentially worse. And they said they feared other American cities would be ill-equipped to handle such an epidemic.