Positive samples of West Nile found in Mathews and Bayou Blue

Lafourche Parish Government announced that they were notified of two positive samples for West Nile in the Mathews and Bayou Blue areas. During the evening hours, trucks sprayed in an effort to reduce/maintain the vector population below the critical level on the evenings of August 25, 26 and 27.

They were informed by the Louisiana Animal Disease Diagnostic Laboratory that these mosquito sample were positive for West Nile Encephalitis (WNV) in Zone L19, and Zone L25B from a sample taken on August 21.

In accordance with the Expanded Transmission Protocol, the following suggestions were made:

1) The location described will serve as the epicenter from which inspection, sampling, and control efforts will radiate.

2) Personnel will be assigned to inspect the immediate area surrounding the epicenter and to continue outward for an approximate five city block area depending upon the geographic location, the topography, and the surrounding conditions. The purpose of the search will be to locate vector mosquito (the Southern House Mosquito and/or the Asian Tiger) breeding sites. Once located, Mosquito Control will address the larvae with the feasible means necessary to control the situation.

3) Residents in the area will be made aware that there is a heightened potential for encephalitis infection in their neighborhood and that personal protection and yard sanitation is recommended. This will be done by distributing informative literature within an approximate five city block radius of the epicenter.

4) Gravid Traps will be used to sample the adult mosquito population in a five City block area radiating from the epicenter. The number of mosquitoes collected will serve to quantify the adult population and provide specimens for testing

5) During the evening hours, truck mounted sprayers were assigned to Spray Zone L19 and Zone L25B in an effort to reduce/maintain the vector population below the critical level. Spraying was conducted on the evenings of August 25, 26 and 27, 2023.

6) The efficacy of this operation will be determined through the use of Gravid Traps that are scheduled for operation following the spray efforts. The number of mosquitoes collected will serve to quantify the adult population and provide specimens to be submitted for testing in our laboratory. This will reduce turn-around time of results to one or two days. Elevated abatement operations will continue until vector mosquito numbers fall below established threshold levels.