News Details

First Human Case of West Nile Virus in Solano County for 2015

October 1, 2015

SOLANO COUNTY – Public health officials confirmed today the first human case of West Nile virus (WNV) infection in Solano County for 2015.

"The person is an adult resident of Suisun City and is now home after a hospitalization for West Nile Virus-associated meningitis," said Michael Stacey, MD, MPH, Solano County Chief Medical Officer and Deputy Health Officer.

As of September 30, 2015, the California Department of Public Health reports that, in addition to the Solano County case, there have been 201 human cases of WNV from 27 counties in California.

Symptoms of West Nile fever include headache, fatigue and fever, skin rash on the trunk of the body, swollen lymph glands and eye pain.  The most severe forms of WNV infection affect the central nervous system causing meningitis and encephalitis.

“Four out of five people (or 80 percent) who are infected with WNV will not develop any symptoms at all,” explains Dr. Stacey.  “The others (nearly one out of five) will usually develop West Nile fever and notice mild, flu-like symptoms.  However, less than one percent of those infected will develop severe neurological disease, which is what happened to this WNV case.”

WNV is transmitted to humans and animals through the bite of an infected mosquito.  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 WNV. 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. Anyone can be infected with WNV, but 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 people with diabetes and/or hypertension have a higher risk of developing severe illness.

To avoid being bitten by mosquitoes, county officials recommend the following:

- Dawn and dusk: Mosquitoes are most active in the early morning and evening.  Residents should avoid being outside at these times.  If you are outdoors, wear long-sleeved shirt and long pants and use insect repellent.

- Drain: Mosquitoes lay their eggs on standing water.  Residents should eliminate all sources of standing water on their property and drain empty flower pots, buckets, barrels, old car tires, rain gutters and pet bowls.  If you have an ornamental pond, contact the Solano County Mosquito Abatement District at (707) 437-1116 for a free mosquito fish.

- DEET: Insect repellents keep mosquitoes from biting.  Apply an EPA-registered insect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR3535 according to the manufacturer's instructions.

- Doors and windows: Residents should ensure that their doors and windows have tight-fitting screens to keep mosquitoes out.  Repair or replace screens with tears or holes.

To date this season, there have been nine (9) confirmed WNV positive birds in Solano County found in the cities of Dixon, Suisun, Vacaville, Benicia, and Vallejo.  The Solano County Mosquito Abatement District also confirmed that mosquito samples collected in Suisun Marsh, Vacaville and Fairfield have also tested positive for WNV this year.

“We work hard to control the mosquito populations throughout the County and use all the tools that we have; however, I would like to emphasize the availability of effective mosquito repellents and encourage residents to use them regularly,” said Richard Snyder, Solano County Mosquito Abatement District Manager.  “I also urge residents to ensure that they do not have any standing water on their property and to report any unmaintained swimming pools by giving us a call.”

Residents are encouraged to report all dead birds and dead tree squirrels online at www.westnile.ca.gov or by calling 1-877-WNV-BIRD (877-968-2473).  Additional information about WNV can be found on the internet at www.westnile.ca.gov or www.cdc.gov.