2003 West Nile Virus Surveillance Season Concludes in Vermont

For Immediate Release: November 25, 2003

Contact: Patsy Tassler, Ph.D.
Vermont Department of Health

BURLINGTON—The Vermont Department of Health has concluded the statewide 2003 West Nile virus surveillance season. Due to the increasingly cold weather, there is little risk of West Nile virus transmission because mosquito activity is at a minimum. Routine surveillance of mosquito activity will resume in the spring of 2004.

In retrospect, surveillance findings from this year were similiar to findings in 2002. The virus is tracked by testing dead birds and mosquito pools for the virus, and from reported cases of human and horse infections. Data for the 2003 season can be found on the Vermont Department of Health web site at: www.healthyvermonters.info/hs/epi/idepi/westnile/wnvhome.shtml

The Vermont Department of Health received 1,751 dead bird reports during the 2003 season, and 827 of those birds were tested for the virus. A total of 116 birds tested positive for West Nile virus, along with three humans and four horses. In the United States, 8,740 human cases of West Nile virus infection were reported, with 189 resulting in death.

Dr. Patsy Tassler, Health Department Epidemiologist, recommends that horses be vaccinated against the virus. “West Nile virus will be here again next year. Horse owners should work with their veterinarians to protect horses against virus infection.” Dr. Tassler added, “nationally, over 14,000 equine cases of West Nile virus were reported in 2002, but that number was reduced to fewer than 4,500 in 2003, due in part to vaccination.”

Although there is no human vaccine for West Nile virus, people can reduce their risk of exposure by avoiding mosquito bites and eliminating mosquito breeding habitats.

West Nile virus was first documented in the U.S. in 1999 and in Vermont in 2000. Nationally, 45 states have documented West Nile virus activity to date in 2003.