'Significant increase' in human cases of West Nile virus in California

SACRAMENTO (KABC) -- There has been a "significant increase" in human cases of West Nile virus in California, and the proportion of West Nile virus-infected mosquitoes in the state is at the highest level it's ever been, the California Department of Public Health announced Wednesday.

Infected mosquitoes transmit the virus to humans and animals through bites. There have been 181 human cases of West Nile virus reported in California to date in 2014, compared to 101 human cases in the same time period in 2013. The virus has been found in 36 counties in California, according to the department.

"Last week, 52 new human cases were reported to CDPH. We expect to see more people become infected as this is the time of year when the risk of infection is the highest," said Dr. Ron Chapman, director of the California Department of Public Health.

"West Nile virus is certainly established in our communities, and so there is always the potential that someone could be bitten by a mosquito that's infected with West Nile virus," said Barbara Cole, director of Disease Control, Riverside County Department of Public Health.

Californians are reminded to be vigilant against the threat of the virus. Most people are not at risk for serious illness, but people 50 years old and older and people with diabetes and/or with high blood pressure are at greatest risk of developing serious complications. Less than 1 percent of individuals can develop serious neurologic illness like encephalitis or meningitis.

The California Department of Public Health recommends that individuals prevent exposure to mosquito bites and West Nile virus by practicing the "Three Ds":
  • DEET: Apply insect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR3535 according to label instructions. Repellents keep the mosquitoes from biting you. DEET can be used safely on infants and children 2 months of age and older.

  • Dawn and dusk: Mosquitoes bite in the early morning and evening so it is important to wear protective clothing and repellent if outside during these times. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.

  • Drain: Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, including flower pots, old car tires, and buckets. If you know of a swimming pool that is not being properly maintained, please contact your local mosquito and vector control agency.


California's West Nile virus website includes the latest information on West Nile virus activity in the state. Californians are encouraged to report all dead birds on the website or by calling toll-free 1-877-WNV-BIRD (968-2473).

Copyright © 2020 KABC-TV. All Rights Reserved.