October 15, 2021
West Nile Virus detected in sentinel chicken
MOBILE, Ala. – A sentinel chicken used by the Mobile County Health Department (MCHD) to
detect mosquito-borne diseases in the community has tested positive for West Nile Virus (WNV).
The coop was in the 36560 ZIP Code.
WNV, which is a form of mosquito-borne encephalitis, has been confirmed by laboratory results,
according to Dr. Bernard H. Eichold II, Health Officer for Mobile County. This is the second
positive test in the last few weeks for Mobile County.
“There are no health benefits to being bitten by a mosquito,” Eichold said. “Don’t let your guard
down. WNV has a human mortality rate of between 3to 15 percent, 50 to 75 percent, while Eastern
Equine Encephalitis is between 50to 75 percent. EEE is a very serious mosquito-borne illness.”
Humans with WNV and other mosquito-borne diseases often have symptoms of high fever, severe
headache, nausea, stiff neck, confusion, muscle weakness, paralysis, disorientation, and seizures
that are severe enough to require medical attention, Eichold said. In rare cases, WNV can cause
coma or death. The seriousness of an illness may depend on a person’s health and age. WNV
affects the elderly most severely, health data shows.
“The public should assume that there are mosquitoes carrying the disease throughout Mobile
County,” Dr. Eichold said. “Don’t let your guard down.”
The risk of encephalitis spread by mosquitoes is highest from August through the first freeze in
the fall, Dr. Eichold said. Vector Services will increase spraying and conduct door-to-door surveys
in the immediate areas. Inspectors will also attempt to trap adult mosquitoes and test them for the
presence of WNV.
Health officials warn that it is extremely important that people taking part in outdoor activities
make every effort to reduce their exposure to mosquitoes and should always keep mosquito
repellent with them when outdoors. Mosquito activity peaks at dusk and again at dawn.
WNV is transmitted from bird to mosquito to bird. Mosquitoes can spread these viruses by feeding
on the blood of infected birds and then biting another host animal or mammal such as a human or
Although humans and horses can become ill from the infection, the disease cannot be spread from
people or horses. The likelihood of transmission to humans and horses can be decreased by
personal mosquito avoidance and the use of WNV and Eastern Equine Encephalitis (EEE) vaccines
in horses. There are no WNV or EEE vaccines available for humans.
To report an issue with mosquitoes, call 251-690-8124 or email VectorServices@mchd.org. To
learn more, please visit https://mchd.org/vector-control.