MOBILE, Alabama – For more than 25 years, the Mobile County Department of Health’s vector control has monitored sentinel chickens placed throughout the county to help detect the presence of mosquito-borne viruses.
The process started again this week as MCHD received 100 newly hatched chicks.
A special facility houses the herd at Vector Services (a vector is an insect, rodent, or animal capable of harboring or transmitting disease to humans) in downtown Mobile.
Each day, the staff will feed the chicks, put them in cool water and clean the lamp-heated cage.
This process will continue until the chicks can be moved to the larger chicken coop located on the Vector Services property.
It takes several months for the chicks to mature enough to be placed in the field.
Vector services staff said it will likely be in May or June before these chickens are put into service.
Once mature, the chickens are vaccinated against fowl pox and the initial blood sample is taken to ensure they are negative for any disease.
At this point, the hens – roosters are not included in the study – are banded for identification and tracking purposes. The birds are dispersed in 13 co-ops located in various predetermined locations in Mobile County.
Blood samples are taken weekly from the wings of two hens at each location, usually on Mondays.
MCHD processes the blood samples and sends them to a lab in Tampa, Florida. Test results are available later this week. Tests can reveal the presence of Eastern Equine Encephalitis, West Nile Virus, and St. Louis Encephalitis.
With the use of 13 henhouses, only 52 hens are used at a time. The rest is kept in reserve. If a test is positive for a disease, it is removed from the field. If two birds in the barn are positive, all four birds are replaced.
MCHD started a project with the University of Southern Alabama in 2018 to test samples from adult mosquitoes. This expanded detection of the disease to include Zika, Dengue and Chikungunya using high throughput molecular methods.
The program continues in the fall and generally ends in November. At this point, the hens are distributed to the general public on a first come, first served basis.
A new group of 100 chicks will start the program the following spring, as they did this week.