West Nile virus-infected bird confirmed

ALBANY — New York has its first confirmed finding of West Nile virus for 2001, State Health Commissioner Antonia. C. Novello, M.D., M.P.H., Dr. P.H., said.

A crow collected in Yorktown, Westchester County on May 10 was infected with the mosquito-borne virus, according to results from the State Health Department’s Wadsworth Center laboratories. The infected crow is the first among 407 birds collected and submitted to the State Health Department since January 1, 2001 to test positive.

State health officials say the finding of an infected bird is not unexpected and does not indicate an imminent human health risk. Crows are more likely than birds of other species to die if they are infected with West Nile virus. Data collected in New York during the past two years indicate that West Nile virus primarily circulates between birds and mosquitoes this early in the season. Infected mosquitoes bite birds, which subsequently transmit the infection to other mosquitoes, as the cycle continues. Last year, West Nile virus was confirmed in birds and/or mosquitoes in 61 of New York’s 62 counties.

Human health risk from West Nile virus only occurs when the amount of virus intensifies in a particular location. Therefore, all New Yorkers are urged to help interrupt the infection cycle by taking steps to reduce areas of standing water around their properties where mosquitoes can breed. The State’s West Nile Virus Response Plan also advises localities to consider using larvacides to eradicate mosquitoes in the aquatic stage before they become biting adults.

Dead birds, particularly crows, continue to be an excellent indicator of the presence of West Nile virus. However, unlike last year, when counties were asked to submit hundreds of birds for testing, the 2001 response plan stresses the importance of closely tracking the number of dead crows and the birds’ location, rather than submitting all dead birds that are found. Cooperation by the public in reporting dead crows will be essential, since research suggests that the number of dead crows per square mile can be used as a measure of the potential health risk to humans.

Persons who notice dead birds, especially dead crows, are encouraged to report the sighting, including details about where the bird is located, to their local health department. Even if the bird is not collected and tested, the report itself will provide vital information.

The following strategies are recommended to reduce mosquito-breeding sites:

• Dispose of tin cans, plastic containers, ceramic pots and similar water-holding containers.
• Remove all discarded tires on your property. Used tires have become the most common mosquito breeding ground in the country.
• Drill holes in the bottom of recycling containers that are kept outdoors.
• Make sure gutters drain properly, and clean clogged gutters in the spring and fall.
• Turn over plastic wading pools and wheelbarrows when not in use.
• Change the water in birdbaths.
• Clean and chlorinate swimming pools, outdoor saunas and hot tubs.
• Drain water from pool covers.
• Use landscaping to eliminate stagnant water that collects on your property, clean up leaf litter and similar organic debris.

To keep mosquitoes from getting inside the home, persons should make sure that all doors and windows have screens and that the screens are in good repair.

Both New Jersey and Connecticut have confirmed West Nile virus infection in birds thus far during 2001. No human cases have been reported. The virus sometimes causes mild, .flu-like symptoms but can also produce serious complications, including encephalitis (inflammation of the brain). Persons at greatest risk of becoming seriously ill from West Nile virus are individuals over the age of 50. During 2000, 14 New Yorkers were hospitalized for treatment of West Nile virus, one of whom later died.

The New York State Department of Health has many informational materials about West Nile virus and how New Yorkers can help to Fight the Bite. Those materials, along with the 2001 West Nile Virus Response Plan, are posted at www.health.state.ny.us.