Mobile County has reported the first case this year of human West Nile Virus (WNV), which is a form of mosquito-borne encephalitis (brain inflammation).

According to Dr. Kevin P. Michaels, Health Officer for Mobile County, the exposure occurred in June.

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. In rare cases, WNV can cause coma or death. The seriousness of the illness may depend on a person’s health and age. WNV is most likely to affect the elderly negatively.

The Mobile County Health Department is warning that it is essential that people taking part in outdoor activities make every effort to reduce their exposure to mosquitoes and should always keep mosquito repellent with them outdoors. Mosquito activity peaks at dusk and again at dawn.

WNV is transmitted from bird to mosquito, according to health authorities. 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 a horse.

The risk of encephalitis spread by mosquitoes is highest from August through the first freeze in the fall. Vector Services will increase spraying and conduct door-to-door surveys in the immediate areas where the infection occurred. Inspectors will also attempt to trap adult mosquitoes and test them for the presence of WNV.

WNV can target the nervous system in fewer than 1% of cases. For those in whom the nervous system is affected, the risk of death is 10%.

The virus was discovered in Uganda in 1937 and was first detected in North America in 1999, where it had a severe effect on horses in the U.S.

Before a veterinary vaccine was produced, 40% of affected horses died from the virus.

Health authorities suggest filling out a mosquito complaint form if they suspect an infection of WNV. The form can be found here or by calling 251-690-8124.

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