WASHINGTON, D.C. and ATLANTA -- The nation's first human case of West Nile Virus (WNV) in 2003 was confirmed in South Carolina yesterday by the Centers for Disease Control and Prevention (CDC). WNV, a seasonal infection transmitted by mosquitoes, grew from an initial U.S. outbreak of 62 disease cases in 1999 to 4,156 reported cases, including 284 deaths, in 2002.
"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; however, the recurrence of West Nile Virus in humans is a compelling reminder of the importance of individual preparedness in preventing disease," said Dr. Julie Gerberding, CDC director. "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, long-sleeved 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.
In 2002, WNV spread to all but six states, with 39 states and the District of Columbia reporting human cases. To date, WNV activity detected in mosquitoes, birds, and horses is comparable to that observed last year.
West Nile virus may be transmitted when an infected mosquito bites a human to take in blood. Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. In addition, recent investigations confirmed WNV transmission through transplanted organs and transfused blood. The recent introduction of routine WNV screening of blood donations should greatly reduce the risk of spread of WNV through transfused blood.
Only about two persons of every 10 who are bitten by an infected mosquito will experience any illness. Although illness from WNV is usually mild, serious illness and death are possible, particularly for persons over the age of 50.
More information about WNV can be found at www.cdc.gov.