West Nile Virus
What is West Nile Encephalitis?
West Nile encephalitis had never been documented in the Western Hemisphere before the late summer of 1999, when an outbreak occurred in the New York City metropolitan area. In 1999, the Centers for Disease Control and Prevention confirmed 62 human cases of encephalitis, including seven deaths, although the actual human infection rate was much higher. Most people who are infected with the West Nile virus have no symptoms or may experience mild illness such as fever, headache, body aches, mild skin rash, or swollen lymph glands.
Infected mosquitoes transmit the West Nile virus. These mosquitoes usually bite and infect wild birds -- the primary host of the virus -- but can also infect horses and other mammals, in addition to humans. In September 2000, the first cases of West Nile virus were confirmed in birds, mosquitoes, and a horse in Pennsylvania. By 2002, West Nile virus had spread throughout most of the United States.
How did the State of Pennsylvania and Penn State Respond?
Since 2000, the state government has provide millions of dollars for Pennsylvania's West Nile Virus Surveillance Program. This funding has been used to prevent and mitigate the potential public-health effects of the West Nile virus on the citizens of the Commonwealth. The funds will provide necessary staffing and an improved epidemiological infrastructure to detect the virus.
The Pennsylvania Departments of Health, Environmental Protection, and Agriculture have developed a comprehensive, statewide plan to detect and respond to a virus outbreak in Pennsylvania. Specifically, the Department of Health conducts laboratory testing to confirm West Nile virus cases in dead bird samples. They are monitoring any possible human cases and also working with health care providers across the state to educate them about the signs and symptoms of West Nile virus infection. The Department of Environmental Protection works with representatives from all 67 counties on a comprehensive mosquito surveillance and control network. The Department of Agriculture is monitoring animal populations for any signs of the virus.
Penn State's College of Agricultural Sciences took a proactive role on this issue. In April 2000, a West Nile Virus Coordinating Committee was assembled. This committee developed publications, worked with Pennsylvania state agencies, and established contacts outside the University. In addition, Penn State Extension designated one person in each county office to serve as a West Nile virus contact person. In recent years, each county now has one official WNV county coordinator who may be from Extension, but could also be from the County Commissioners Office, Conservation Districts, Department of Environmental Protection Regional Offices, or other agency.
For more information about West Nile Virus, please visit the links below to Pennsylvania's West Nile Virus website, Extension fact sheets, EPA fact sheets, and other websites about WNV.
Pennsylvania's West Nile Virus Website
Find the current surveillance information for the state and by county. Links are also provided for all the previous years surveillance results.
West Nile Virus County Coordinators for mosquito surveillance and control.
Dead bird sightings can be reported to the Pennsylvania West Nile Virus program by filling out the online form. However, reports submitted between October 1 and April 30 will not be picked up or tested for West Nile virus.
Penn State West Nile Virus Fact Sheets
The West Nile virus, which can cause encephalitis, is commonly found in humans, birds, and other animals in Africa, Europe, Asia, and the Middle East.
EPA West Nile Virus Fact Sheets
West Nile Virus Websites
from the Centers for Disease Control and Prevention
from the U.S. Geological Survey
from the National Pesticide Information Center
This website provides support and information for encephalitis survivors, caregivers, and loved ones.