Two different instances of mosquito-related illnesses this week have been reported to the Fresno County Department of Public Health by the Fresno Mosquito and Vector Control District. In one case, a human case of West Nile Virus was reported and in the other, mosquitos carrying encephalitis have been found.
On July 5, the district reported that Culex mosquitoes were found in Fresno near East Floradora Avenue and Highway 41 and Shields and Van Ness avenues that tested positive for Saint Louis encephalitis virus. This disease is transmitted through infected mosquitos’ bites and can cause inflammation of the brain.
The next day, another report came in confirming the first positive case of West Nile Virus in Fresno County. Since June 25, there have been nine human cases of WNV in the state, but no fatalities.
“Confirmation of this case is a strong reminder that everyone should increase efforts to protect themselves and their families from mosquito bites,” Fresno County Health Officer Dr. Ken Bird said.
While most people infected with encephalitis have no apparent illness, others experience fever, headache, dizziness, nausea and feeling tired. The onset of illness ranges from 5 to 15 days. Signs and symptoms last for a period of several days to a week. Severe symptoms include fever, headache, stiff neck, confusion and altered level of consciousness. Coma, convulsions, paralysis and sometimes death may occur. The fatality rate is 5-15 percent.
Elderly people and those with a weakened immune system are more at risk for developing severe symptoms.
There is no vaccine for encephalitis and health officials warn that reducing exposure to mosquitos is the best defense. Officials advise residents to use repellent, wear protective clothing, replace torn window screens, avoid peak biting hours at dusk and dawn and rid your property of standing water to eliminate breeding grounds. Residents are also encouraged to contact mosquito abatement districts to report poorly maintained swimming pools or water features that appear green.
For more information, go online to www.fresnomosquito.org.