Viruses that are carried by mosquitoes are called arboviruses. Indian River County’s population is older so arboviruses are a local concern, because people over 50 have the highest risk of becoming seriously ill. Florida Department of Health in Indian River County (DOH-Indian River) partners with Indian River County Mosquito Control District to prevent the spread of mosquito-borne illness in the county.
Sentinel chickens are monitored and tested for exposure to arboviruses. Chickens are good sentinels because they do not get sick from these viruses or transmit them to humans. Indian River Mosquito Control District maintains 8 flocks of 6 carefully raised chickens in cages located throughout the populated eastern half of Indian River County. Like normal barnyard chickens, the sentinel chickens are readily fed upon by mosquitoes. However, sentinels are tested for prior infection with St. Louis Encephalitis Virus, West Nile Virus, and Eastern Equine Encephalitis virus before they are placed in the field. Each sentinel has an additional blood sample taken each week of the surveillance season. The blood samples are tested weekly by a Florida Department of Health Laboratory in Tampa, which can determine when antibodies to either of the tested viruses are present.