The first human case of West Nile virus (WNV) in Ventura County this year is one of 51 news cases reported in California during the past week, according to The California Department of Public Health (CDPH) today.

West Nile virus
Culex quinquefasciatus

The following counties reported cases in the past week: Los Angeles (16), Orange (25), Riverside (2), San Bernardino (1), San Diego (3), Santa Clara (2), Sutter (1), and Ventura (1).

This brings the state total to 705, well more than double the number of cases reported last year at this time (339).

An additional WNV death in Sutter County, the 3rd, brings California’s fatality total to 23. During all of 2013, 15 deaths due to WNV were reported in California.

Across the US as of October 28, a total of 47 states and the District of Columbia have reported West Nile virus infections in people, birds, or mosquitoes. Overall, 1,668 cases of West Nile virus disease in people have been reported to CDC. Of these, 976 (59%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 692 (41%) were classified as non-neuroinvasive disease.

West Nile virus is an arthropod-borne virus (arbovirus) most commonly spread by infected mosquitoes. West Nile virus can cause febrile illness, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).

It was first detected in North America in 1999, and has since spread across the continental United States and Canada.

Most people get infected with West Nile virus by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals.

In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, and from mother to baby during pregnancy, delivery, or breastfeeding, according to the CDC. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page