West Nile Virus Buzzes In Early This Year

ATLANTA, Georgia, June 2, 2004 (ENS) - West Nile virus is appearing earlier this year than ever before, according to data compiled by the Centers for Disease Control and Prevention in Atlanta. Last year, the first human case of the virus was confirmed on July 8 in South Carolina. This year human cases already have been reported in Arizona and New Mexico.

Arizona health officials reported the first human case of West Nile virus in the state on Thursday, much earlier than Arizona's normal mosquito season, which runs from August through September in that arid state.

At a news conference, Dr. Jonathan Weisbuch, director of the Department of Public Health in Maricopa County, where Phoenix is located, said an adult from the county developed symptoms May 8, and was admitted to a hospital. Weisbuch said that person has now fully recovered.

"This is much earlier than we expected," Weisbuch said. "It's going to be a longer season. We could see several hundred cases," he said.

A human case of West Nile virus was reported in New Mexico on Wednesday. The man from San Juan County had mild symptoms, was hospitalized and has recovered, said the New Mexico Department of Health.

"This means West Nile Virus season has started early this year," said New Mexico Health Secretary Patricia Montoya.

“New Mexico’s first human case last year was in July,” said Paul Ettestad, the state public health veterinarian for the New Mexico Department of Health. In 2003, New Mexico had a total of 209 confirmed cases and four fatal cases of the virus.

West Nile virus has killed more than 560 people in the United States since it was first discovered in New York in 1999. Last year was the first year the virus appeared in regions west of the Continental Divide.

The bite of an infected mosquito carries the West Nile virus. (Photo by Sinclair Stammers courtesy WHO/TDR)

In addition, recent investigations have confirmed that the virus can be transmitted through transplanted organs and transfused blood, the Centers for Disease Control (CDC) says. The recent introduction of routine West Nile virus screening of blood donations should reduce this risk.

Colorado had the greatest number of human cases in the country last year - 2,947 of the 9,862 human cases reported to the Centers for Disease Control (CDC). In 2003, 264 people died from the disease, 61 of them in Colorado.

This year, infected animals or birds have been reported by Alabama, Arizona, Arkansas, California, Florida, Georgia, Illinois, Kentucky, Louisiana, Michigan, Mississippi, New Jersey, New York, Ohio, Oklahoma, Pennsylvania and Texas.

In California, West Nile virus has infected 157 wild birds, most of them crows from San Bernardino, Riverside and Los Angeles counties, state and local health officials reported Friday.

Infected dead birds were found in 38 cities, with the greatest number found in Fontana, Rialto and San Bernardino.

In Virginia, a six year old thoroughbred mare in Culpeper County was euthanized after falling ill with West Nile virus, the first case found in a Virginia horse this year, the state Department of Agriculture and Consumer Services said on Friday. Symptoms first appeared on May 1, 10 weeks earlier than any of the previously reported cases of the virus in Virginia.

State officials say it is not too late to vaccinate horses for the virus. West Nile vaccine for horses requires two doses administered several weeks apart. The vaccine takes four to six weeks from the second dose to be effective.

The first pool of mosquitoes in Indiana infected with the West Nile virus has been found earlier than in previous years, county health officials said on Friday. The infected mosquitoes were found in traps on the north side of Indianapolis, a site where the virus was detected last year, the Marion County Health Department said.

Long sleeves and long pants help protect against bites by mosquitos that might be carrying the West Nile virus. (Photo courtesy CDC)

Only about two persons of every 10 who are bitten by an infected mosquito will experience any illness, according to the CDC. Although illness from West Nile is usually mild, serious illness and death are possible, particularly for persons over the age of 50.

CDC Director Dr. Julie Gerberding said, “Public health workers across the country have been preparing for this moment for several months. It is impossible to predict what this year’s season will hold. Knowing how rapidly West Nile Virus spread last year, we urge everyone who spends time outdoors to take steps to protect themselves from mosquito bites.”

“Three simple actions can help prevent infection: avoiding mosquito bites by using insect repellants with DEET and wearing light, longsleeved clothing, mosquito proofing your home by emptying standing water and installing screens, and helping your community by reporting dead birds to local health authorities,” Gerberding said.