More than 750 mosquito samples have tested positive for the virus this year as health officials report a sharp rise in human infections.

Irvine City News | October 1, 2026

Orange County health officials have confirmed the county’s first West Nile virus-related deaths of 2026 as infections and mosquito activity continue to rise.

The OC Health Care Agency has received 36 reports of human West Nile infections this year. Most infected people never develop symptoms, meaning health officials believe the actual number of infections is considerably higher.

Orange County Mosquito and Vector Control officials say more than 750 mosquito samples have tested positive for West Nile this year, compared with 186 during all of 2025. Officials recently described 2026 as one of the county’s most active West Nile seasons on record.

Residents are urged to eliminate standing water, use mosquito repellent and take extra precautions around dawn and dusk.

This article draws on information from the OC Health Care Agency and Orange County Mosquito and Vector Control District, with additional reporting by CBS Los Angeles, ABC7 and the Los Angeles Times.