Should you worry about getting sick from mosquitoes in Merced?
AI-generated summary reviewed by our newsroom.
- Merced reports two West Nile human cases this year; abatement urges bite prevention.
- Eliminate standing water and report neglected pools to reduce mosquito breeding.
- Use EPA-approved repellents like DEET, picaridin or oil of lemon eucalyptus.
From 150 feet away a mosquito can smell the carbon dioxide in your breath — that’s how these itch-inducing biting insects locate their next meal. But mosquitos are more than just a seasonal annoyance: the Centers for Disease Control list them as the world’s deadliest animal, because they carry diseases including West Nile virus and Dengue fever.
And the best way to prevent mosquito-borne illnesses is to prevent mosquito bites, according to the Merced County Mosquito Abatement District.
There have been two human cases of West Nile virus in the county this year, said Adara Culpepper, public information officer for the Merced County Mosquito Abatement District. The virus, which originates in birds and is spread to humans and other mammals after mosquitoes bite an infected bird, varies greatly in severity.
“Eighty percent of people infected with it will never show a single symptom,” said Culpepper, “About 20% will have really mild flu-like symptoms, but 1% of people will develop what’s called a neuroinvasive form of the virus.” She said the neuroinvasive form of the viral infection is the most likely form to be fatal.
There are no reported fatalities from West Nile virus in Merced this year and only 3 deaths from the disease in California. Last year there were 3 reported human cases of West Nile in Merced County and one of those cases was fatal. Those most likely to experience severe symptoms of the virus are older adults, young children, and pregnant people.
The other mosquito-born illness that is prevalent in California is Dengue fever. According to the California Department of Public Health, there has only been one case of Dengue in Merced County this year. Culpepper added that the case didn’t originate in California but was found in a patient who had just returned from international travel
How to keep the mosquitoes away
The abatement district says preventing mosquito bites is the best way to prevent mosquito-borne illnesses.
Eliminating standing water, which serves as a breeding area for mosquitoes. Common containers that can become sources of standing water include plant pots, old car tires and outdoor pet bowls.
If you observe sources of standing water including neglected swimming pools that are not on your property, you can report them by placing a service request on the Abatement District website.
According to Community Medical Centers in Fresno, California mosquito season begins in March and ends in the fall when temperatures drop.
In addition to eliminating breeding sites, “when you go outside, make sure you’re wearing some type of mosquito repellent.” Culpepper said.
She recommended three ingredients that the Environmental Protection Agency has scientifically proven to repel mosquitoes: She recommended three ingredients that the Environmental Protection Agency has scientifically proven to repel mosquitoes:
She recommended three ingredients that the Environmental Protection Agency has scientifically proven to repel mosquitoes:
DEET, which is safe for use by adults and children older than 3 months of age. Picaridin Oil of Lemon Eucalyptus
She recommended dressing infants in long-sleeve clothing or keeping them inside.
What is the county plan for mosquito abatement?
In addition to monitoring for standing water, the Abatement District also sprays within the county. The low-flying planes seen over the city limits of Merced, Atwater, Delhi, Hilmar and Livingston over the past few weeks are releasing chemical treatments to kill adult mosquitoes.
“These treatments that we’re doing, this is called ‘adulticiding’” said Culpepper who explained that the treatment kills any mosquito that touches it within three to five days. She said the department regularly switches the chemicals used as mosquitoes develop immunity.
This story was originally published October 4, 2025 at 5:00 AM.
