West Nile Virus Similar To Israel '98 Virus.
Two competing laboratories have simultaneously confirmed the identity of the virus as West Nile and have found it to be identical to a virus isolated in the Middle East.
The remaining mystery is how the virus, not previously linked to human infections, came to the United States.
Dr. Robert Lanciotti and his colleagues at the Centers for Disease Control and Prevention in Fort Collins, Colo., as well as Dr. Ian Lipkin's group at the University of California at Irvine have both completed their sequencings of the New York City '99 encephalitis virus.
"What was unexpected, and in fact shocking to us, is that the Israel '98 virus ... was 99.8% similar," Dr. Lanciotti said at the meeting.
The Israel virus was isolated from a dead bird in 1998. Whether the Israel '98 virus had also infected humans is unknown. To date, there have been no human cases of West Nile encephalitis reported in Israel.
The CDC scientists had speculated that the New York virus would be most closely related to a West Nile strain called Volvograd, which caused an outbreak in that Russian city last year.
Dr. Lipkin had initially hypothesized, based upon an incomplete sequence, that the virus looked closer to the Kunjin variant of West Nile (FAMILY PRACTICE NEWS Nov. 1, 1999, p. 6). His group used a viral isolate from human brain tissue to complete the sequence. The updated results were published in the Dec. 4 issue of Lancet.
The CDC group completed their sequence with a viral isolate from the tissue of a flamingo from the Bronx Zoo.
Comparison of viral sequences from affected humans, crows, mosquitoes, and horses were the same, confirming that a single virus was circulating during the Northeastern epidemic. Their results were published in the Dec. 17 issue of Science.
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|Publication:||Family Practice News|
|Article Type:||Brief Article|
|Date:||Jan 1, 2000|
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