Mosquito-Borne Illness Detection
Mosquitoes can spread certain viruses and pathogens that cause illness in people and animals. Different viruses or pathogens are transmitted by different species of mosquitoes. Not every mosquito can transmit disease.
The main mosquito-borne viruses we see in Pinellas County are Eastern Equine Encephalitis (EEE), St. Louis Encephalitis (SLE) and West Nile Virus (WNV). In addition to these viruses, which cycle in our area on a regular basis, imported cases (infections caused by a mosquito bite that occurred outside the county) of Dengue, Malaria, Chikungunya and Zika occur yearly. Pinellas County has the mosquito species that can transmit these diseases, so we work closely with the Florida Department of Health (FDOH) on imported cases to ensure local mosquitoes don’t pick up the virus or pathogen.
Mosquito traps are one way we can track mosquito populations and assess the potential risk for mosquito-borne illnesses. We have 58 mosquito trap sites throughout the county that are monitored daily or weekly, depending on the type of trap.
One of our certified mosquito identification specialists counts and identifies the mosquitoes by species. This gives us data on which areas have increasing populations of mosquitoes of concern. We base our treatment decisions on data from traps and technician surveys.
Sentinel Chicken Program
We look for the presence of mosquito-transmitted viruses through our sentinel chicken program. Eastern Equine Encephalitis, St. Louis Encephalitis and West Nile are all viruses that are typically passed from bird to mosquito to bird. The primary mosquitoes that transmit these viruses prefer to take bloodmeals from birds, so the illnesses mostly stay in the wild bird population.
If the level of infected birds increases, mosquito species that bite several kinds of animals are at higher risk for becoming infected and transmitting the virus to humans, horses and other animals.
Chickens are an attractive bloodmeal for bird-biting mosquitoes. Although they can be infected with EEE, SLE and WNV and produce antibodies, they do not experience illness and can’t transmit the viruses to uninfected mosquitoes.
We have eight sentinel chicken coops throughout the county and draw blood from the chickens once a week. The FDOH tests the blood for antibodies to those viruses and the chickens serve as an early warning for their presence. We use this information to target mosquito species of concern in areas that have circulating virus.