Related Articles
-Editorial
As summer temperatures rise across the Imperial Valley, public health officials are urging residents to take precautions after the season’s first mosquito pool testing positive for West Nile Virus (WNV) was confirmed in the City of Imperial.
The announcement came from the Imperial County Public Health Department, which reported that the mosquito sample was collected on June 16 and laboratory results were confirmed on June 20. This marks the first confirmed presence of the virus in Imperial County in 2025.
“As the weather warms up, mosquitoes become more active, which increases the risk of mosquito-borne diseases,” said Dr. Stephen Munday, Imperial County Health Officer. “These diseases can be serious, so individuals must protect themselves from mosquito bites.”
To monitor mosquito activity and potential outbreaks, the county’s Vector Control Program operates 53 mosquito traps across city areas, which are checked multiple times each week. County officials emphasize that these surveillance efforts are key to early detection and response.
Jeff Lamoure, Deputy Director of Environmental Health, explained that the county will continue to monitor affected areas and take preventive measures. “Although the positive mosquitoes were collected in a specific area, all county residents should take precautions,” Lamoure said. “That includes using insect repellent and limiting outdoor activity during dusk and dawn.”
West Nile Virus is most commonly transmitted through the bite of infected mosquitoes, which become carriers after feeding on infected birds. Most people infected with WNV do not experience symptoms, but some may develop mild, flu-like illness. In rare cases, particularly among older adults or individuals with weakened immune systems, the virus can lead to severe neurological complications, including inflammation of the brain (encephalitis), seizures, or paralysis.
To reduce the risk of West Nile Virus infection, health officials recommend using EPA-registered insect repellents containing DEET, Picaridin, or oil of lemon eucalyptus. Residents should also wear long sleeves and pants when outdoors, particularly during dawn and dusk when mosquitoes are most active. Ensuring that windows and doors have intact screens can help keep mosquitoes out of the home.
Eliminating sources of standing water is also crucial, as these areas serve as breeding grounds for mosquitoes. Officials advise emptying water from buckets, tires, birdbaths, and flower pots regularly. Pet dishes and fountains should be refreshed at least once a week, and swimming pools must be kept clean and properly circulated.
While no human cases have been reported so far this year in Imperial County, public health authorities stress the importance of remaining vigilant. Early detection in mosquito pools is a reminder that the virus is present in the environment and can spread quickly if left unchecked.
Residents who experience symptoms such as fever, headache, fatigue, or body aches—particularly after recent mosquito exposure—are encouraged to seek medical attention.
West Nile Virus is a mosquito-borne virus that can infect humans, birds, and other animals. It is primarily spread to people through the bite of an infected mosquito. Mosquitoes become infected after feeding on birds that carry the virus.
Most people who are infected with WNV do not develop any symptoms. About 1 in 5 may experience mild, flu-like symptoms such as fever, headache, body aches, joint pain, vomiting, or rash. In rare cases—especially among older adults or people with weakened immune systems—the virus can cause serious neurological conditions like encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes around the brain and spinal cord). These severe cases can lead to paralysis, coma, or even death.
There is no vaccine or specific treatment for West Nile Virus in humans, so prevention—primarily through avoiding mosquito bites—is essential.