Phased Response to Mosquito Surveillance

The following recommendations are intended to guide mosquito control programs and may include other applicable community procedures. All actions are subject to change due to organizational priorities, weather or other unforeseen circumstances.

Risk category	Probability of human outbreak	Public Health Threshold	Recommended response
0	None	No evidence of Mosquito or viral activity	Control Measures Contact community partners Secure necessary control resources to enable emergency response
1	Low	Normal mosquito activity with little or no evidence of viral activity	Control Measures Source reduction through physical and environmental measures Biological – mosquito fish Larvicides (surface oils, biorational bacterial products and insect growth regulators)
2	Moderate	Virus detected inmosquito samples	Control Measures Larvicing of breeding sites around infected trap sites Consider Ground-based ULV adulticide application around positive trap location, with continued mosquito surveillance
3	High	Virus detected in multiple mosquito samples from different times and locations and confirmed human cases	Control Measures Ground-based ULV adulticide application of area around confirmed human case(s) after mosquito trapping confirms the presence of disease Ground-based ULV adulticide application of positive mosquito sites and expanded areas around sites Consider aerial treatment(s)
4	Outbreak in progress	Multiple human cases confirmed and detection of increased or continued viral mosquito activity	Control Measures Ground-based ULV adulticide application in areas of clustered human cases Recommend aerial adulticide applications in targeted zones

These guidelines were adapted from the Center for Disease Control report “Epidemic/Epizootic West Nile Virus in the United States: Guideline for Surveillance, Prevention and Control, 2003”

Revised: 06/01/13