Imperial County officials warn of mosquito-borne disease risks after local dengue case

IMPERIAL COUNTY, Calif. (KYMA) - As summer temperatures rise, the Imperial County Public Health Department is urging residents, visitors, and travelers to take immediate precautions against mosquito-borne illnesses.

The warning follows a recent investigation where laboratory testing confirmed a locally acquired case of dengue fever in Imperial County. While most dengue cases in California are linked to travel outside the United States, local transmission can occur. In 2025, California recorded 213 dengue cases, 7 of which were locally acquired.

Symptoms typically appear between a few days to two weeks after a bite from an infected mosquito.

• Dengue: Symptoms include sudden high fever, severe headache, pain behind the eyes, joint and muscle pain, nausea, vomiting, swollen glands, and a rash. While most people recover in a week, severe dengue is a medical emergency.
• West Nile Virus & St. Louis Encephalitis: Symptoms include fever, headache, body aches, nausea, vomiting, rash, and fatigue. While many infected people show no symptoms, these viruses can cause severe nervous system complications in older adults and individuals with weakened immune systems.

The Vector Control Program conducts year-round monitoring and treatment, but officials stress that community action is vital to controlling the insect population.

Health officials recommend the following daily precautions:

• Apply Repellent: Use EPA-registered insect repellent when outdoors, even during the day.
• Dress Defensively: Wear long-sleeved shirts and long pants when possible.
• Secure Your Home: Ensure all doors and windows have properly fitted mesh screens.
• Dump Standing Water: Regularly empty containers that hold water, including flowerpots, buckets, old tires, birdbaths, and pet dishes.
• Maintain Pools: Keep swimming pools, spas, and ornamental ponds clean and chlorinated.
• Report Breeding Sites: Contact local authorities to report neglected swimming pools or major sources of stagnant water.

For more details on local monitoring and prevention tips, visit the Imperial County Vector Control Website.