Merced County confirms first local human case of West Nile virus this year
A Merced woman is confirmed to have contracted West Nile virus, marking it the first local human case this year, the Merced County Mosquito Abatement District announced Wednesday.
To date, West Nile virus has also been detected locally in 16 chickens, 12 mosquito pooled samples and one dead bird, according to a county news release.
The 70-year-old Merced County woman is one of 35 individuals stated confirmed to have contracted the virus so far this year. The unidentified female is said to have a neuroinvasive case, according to the release.
A majority of people infected with West Nile do not develop any symptoms, according to the Centers for Disease Control (CDC).
Roughly 1 in 5 infected individuals develop a fever with other symptoms including a headache, body aches, joint pains, vomiting, diarrhea or a rash. Most people recover completely, but fatigue and weakness can last for weeks or months.
About 1 in 150 infected individuals, however, develop a severe illness that affects the central nervous system, causing encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes that surround the brain and spinal cord).
Symptoms of severe illness can include a high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis, according to the CDC. Although severe illness can occur in people of any age, individuals over 60 years of age are at greater risk.
People with certain medical conditions like cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants, are also at greater risk.
West Nile virus is transmitted through the bite of an infected mosquito. Merce County residents are advised to help reduce mosquito breeding and curb the virus’s spread by taking the following steps:
- Eliminate sources of standing water where mosquitoes lay eggs.
- Avoid spending time outside when mosquitoes are most active, such as dawn and dusk.
- Apply insect repellent containing the active ingredient DEET when outdoors. In addition to DEET-based products, the CDC also recommends insect repellent containing oil of lemon eucalyptus and Picaridin.
Reporting and testing dead birds also helps prevent the spread of West Nile virus, the release said. A confirmed case of the virus in dead birds or mosquito samples helps to identify areas that require treatment to reduce mosquito activity.
To report a dead bird, call the California State Hotline at 1-877-WNV-BIRD or report it online at www.westnile.gov.
The Mosquito Abatement District has been locating mosquito breeding sources and treating them by ground or aerial spray equipment as necessary. Especially of concern are neglected swimming pools where West Nile virus-carrying mosquitoes often lay eggs, the release said.
“Public health safety is the District’s main concern with regard to mosquito control,” the release said.
To report mosquito breeding problem areas, Merced County residents can contact the Merced County Mosquito Abatement District at (209) 722-1527 or visit www.mcmosquito.org. Anonymous reports are welcome.
Questions regarding West Nile virus and human infections can be directed to the Merced County Department of Public Health at (209) 381-1200.
This story was originally published September 7, 2022 at 11:45 AM.
