Crows test positive for
West Nile virus in county
The Monmouth County Mosquito Extermination Commission, Tinton Falls, has been notified by the N.J. Department of Health and Senior Services that three dead crows collected in Monmouth County have tested positive for West Nile virus (WNV), bringing the total of dead crows found in the state to four.
The three were collected between April 16 and May 3 in Ocean Township, Howell Township and Tinton Falls. The fourth infected crow was collected in Morris County.
"Crows are certainly the best early indicator that the virus is present in an area," said Douglas Guthrie Sr., superintendent of the mosquito commission.
"Once the crows have been confirmed positive for WNV, our response protocol is to enhance our surveillance efforts and increase our control operations and inspections in the local areas where the crows were found," he continued.
When dead crows are found by any of the 10 local health departments in Monmouth County, the crows are submitted to the state Health Department laboratory. According to Guthrie, the fact that three WNV-positive crows have been found this early in the season, confirms the virus is endemic and here to stay.
The mosquito commission has strategies and mechanisms in place to carry out an effective mosquito control program. The strategies include emphasizing surveillance, larval control and source reduction through long-term drainage projects.
The commission maintains an active surveillance program to track mosquito populations to monitor them for the presence of disease.
"Our program is comprised of two major components that enable us to develop a detailed view of both mosquito nuisance levels and disease potential," stated Anthony J. Acquaviva, senior biologist with the mosquito commission.
"The first of these components is the placement of New Jersey light traps at more than two dozen fixed locations throughout the county," he continued.
The commission has been conducting mosquito trapping with portable traps weekly since April 15, with trapping to continue until the first hard frost of autumn. Daily collections from the traps are analyzed in the lab to determine the number of specimen of each mosquito species. Data from the collections is also used by field inspectors for comparative purposes in treatment plans.
The second aspect involves the use of portable traps to ensure that mosquitoes are subsequently sent for WNV testing. The U.S. Centers for Disease Control’s light and gravid traps are ideally suited to the task of sampling in areas where dead crows indicated the possible presence of the virus, according to Acquaviva. Mosquitoes collected in the traps are then sent to the Department of Health and Senior Services for WNV assay.
Monmouth County is one of three New Jersey counties selected to participate in a Web-based pilot program in which mosquito-control agencies will have immediate access to test results, because with faster reporting, the agency can expedite its decision-making process regarding a mosquito-control response to the virus.
This season, the county will also continue to participate in a sentinel chicken program in a cooperative agreement with the N.J. Department of Agriculture. The mosquito commission maintains four flocks of three to nine chickens, each located in strategic areas throughout the county.
"This year we have placed flocks at more rural locations in the county where very little crow data is obtained, but where a large number of equines could be at risk for WNV," said Sean Healy, a mosquito commission entomologist.
The chickens are sampled on a regular basis and tested by the Department of Agriculture using hemagglutination-inhibition. The information aids the commission in determining the effect the virus may have on the equine population.
For more information about mosquito control and pesticides used in Monmouth County, visit the mosquito commission’s Web site at www.visitmonmouth.com/mosquito.