As West Nile Virus (WNV) activity continues to rise throughout the state, the California Department of Public Health (CDPH) has reported the first human death caused by the virus.
The deceased person was a senior citizen from Nevada County.
“This death is a tragic reminder of how severe West Nile virus disease can be,” said CDPH Director and State Health Officer Dr. Karen Smith. “West Nile virus activity is more widespread in 2015 than in years past. Californians need to be vigilant in protecting themselves.”
WNV is influenced by many factors such as climate, the number and types of birds and mosquitoes in an area, and the level of immunity in birds to the virus.
According to the CDPH, it is possible that the drought has contributed to WNV amplification by reducing sources of water for birds and mosquitoes. As birds and mosquitoes seek water, they are coming into closer contact and amplifying the transmission of the virus.
To date, 35 California counties, including Stanislaus County, have reported WNV activity so far this year. Throughout California, 756 mosquito samples, 254 dead birds, and 43 sentinel chickens have tested positive for WNV.
In Stanislaus County, nine mosquito samples and eight dead birds have tested positive for WNV.
WNV is transmitted to humans and animals by the bite of an infected mosquito. The risk of serious illness to most people is low. However, some individuals – less than one percent – can develop a serious neurologic illness such as encephalitis or meningitis.
People 50 years of age and older have a higher chance of getting sick and are more likely to develop complications. Studies also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.
CDPH recommends that individuals prevent exposure to mosquito bites and WNV by practicing the “Three Ds”:
- DEET – Apply insect repellent containing DEET, picaridin, 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 two months of age and older.
- DAWN AND DUSK – Mosquitoes bite in the early morning and evening so it is important to wear proper 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, by emptying flower pots, old car tires, buckets, and other containers. 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 WNV activity in the state. Californians are encouraged to report dead birds on the website or by calling toll-free 1-877-WNV-BIRD (968-2473).