The Arizona Department of Health Services-Vectorborne and Zoonotic Disease Section
(ADHS-VZD) has overseen a statewide mosquito-borne encephalitis surveillance program
since 1974 to detect for the presence of Western Equine Encephalitis and St. Louis
Encephalitis. The Pinal County Division of Environmental Health has overseen a vector
control program for as many years. However, in 1999 with the introduction of WNV
for the first time in the western hemisphere, the program was expanded to a more
pro-active approach. The Pinal County Division of Environmental Health Vector Program
(PCDEHVP) will continue to work closely with the ADHS to collect and interpret data
on arboviruses that may be present in Pinal County.
The vector program consists of four main areas of focus:
- Mosquito Surveillance
Mosquitoes are collected twice monthly from CO2 traps that are placed at varying
locations throughout the county. The samples are then submitted to the state for
arbovirus testing and species identification.
- Larval Surveillance and Control
Larval control is achieved by reducing mosquito breeding habitats (source reduction).
Larval surveillance consists of dipping potential breeding sites and looking for
larvae and pupae. Larvicides are applied to prevent adult mosquito emergence on
county owned land and right-of-ways. Enforcement action may be taken against breeding
sites located on private property.
- Adult Mosquito Control
Eliminating mosquito breeding sites is priority #1. Larval control if done regularly
will ultimately prevent adult mosquito emergence. Should it become necessary, pesticide
application using a ULV (Ultra Low Volume) sprayer may be used to decrease the adult
- Public Education
Educating the public on reducing mosquito breeding habitats is an important part
of vector control and surveillance. The vector program provides informational literature
to the public on how to reduce mosquito breeding on their own property and how to
prevent WNV from affecting their community.