spokesperson Samantha Mott said the first case was reported to the county on July 7, and cases are confirmed if they test positive in a lab and the individual develops symptoms.

Three of those cases reportedly resulted in neuroinvasive disease, which typically manifests as meningitis, encephalitis or acute flaccid paralysis, and occurs in less than 1% of cases. The county says 11 of the 14 cases under investigation resulted in a hospitalization, and no deaths have been reported.

West Nile Virus is a disease that originates in birds and is passed to humans and other mammals through mosquitoes. The 2023 season has been particularly bad, according to Luz Maria Robles with the Sacramento-Yolo Mosquito and Vector Control District.

“Not only did we have a record amount of rain, a very wet winter — so many different mosquito breeding sources — we've also had very warm temperatures that are ongoing,” she said.

Robles said South Sacramento was a particular hotspot earlier in the season, but the county didn’t have information on where the infected people were from.

“People need to remain vigilant. People need to remain cautious, especially when they spend time outdoors,” Robles said. She added people should drain stagnant water around their home, and wear protective clothing and insect repellent.

In early August, the Yolo County Vector and Disease Control unit sprayed the cities of Woodland and Davis with diluted insecticide from a low-flying plane. Yolo County reported their first human case of West Nile in a Woodland resident on Aug. 10.

“We (spray) when it's absolutely necessary," said Robles. “We know that we have to act quickly to interrupt the virus transmission cycle and to be able to protect public health.”

This year’s cases aren’t yet up on state and national trackers, which currently show that Sacramento has zero human cases. A spokesperson for the California Department of Public Health says there is a “lag time” before the information reaches the state. The department said there have only been 14 human cases reported to them statewide so far this year.

Mott said the county has reported to the state, but generally does not report human cases to the public because they occur every season.

“We report to the public if we have a human death as a result of West Nile,” said Mott.

Robles said human cases will likely be reported through the end of the warm-weather season, likely through November.

People can monitor the spread of the disease on westnile.ca.gov and can learn about spraying operations near them on fightthebite.net.