Bethesda, Md.-The West Nile virus that killed seven in the New York area last year is closely related to a strain of the virus that was isolated in Israel in 1998, a federal public health official said yesterday.

Stephen Ostroff, West Nile coordinator for the Centers for Disease Control and Prevention in Atlanta, said researchers have done genetic comparisons of the virus strain that appeared for the first time in New York in the fall and others that have circulated over the years in Africa, the Middle East and elsewhere.