Last week, the Los Angeles County Department of Public Health (Public Health) confirmed the first human case of West Nile Virus (WNV) infection for the 2016 season in LA County (excluding Long Beach and Pasadena as cases identified in those cities are reported by their local health departments). Illness occurred in an elderly male from the Echo Park area with no prior medical history who was hospitalized for WNV disease in late June and is recovering at home. This case has been confirmed by the California Department of Public Health.

Public domain image/National Atlas of the United States
Public domain image/National Atlas of the United States

“This serves as a warning to residents that West Nile Virus is a serious disease that may require hospitalization and can even result in death for some individuals,” said Jeffrey Gunzenhauser, MD, MPH, Interim Health Officer for Los Angeles County. “Elderly persons and other people with weak immune systems are at highest risk of developing severe illness. Protect yourself from mosquitoes by using insect repellent containing an effective ingredient such as DEET, and eliminating any stagnant water around your home where mosquitoes can breed. Do it for your kids, do it for your grandkids, do it for yourself.”

In 2015 in LA County, 300 human infections and 24 fatalities due to WNV were reported.

In addition, Yolo County confirmed today that two residents have tested positive for West Nile virus. While both residents are symptom-free, West Nile virus can pose a serious health risk.

West Nile virus is most commonly spread to humans through the bite of a mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals. West Nile virus can cause fever, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). Most people (70-80%) who become infected with West Nile virus do not develop any symptoms. About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Less than 1% of people who are infected will develop a serious illness.