Mendocino County Health & Human Services Agency
Healthy People, Healthy Communities
Stacey Cryer, Director
Date: September 9, 2014
Mendocino County Resident Tests Positive for West Nile Virus
From: Mendocino County Health and Human Services Agency – Dr. Craig McMillan, Public Health Medical Director and Dr. Charles Evans, Deputy Director of Communicable Disease Control Program
Mendocino County Health and Human Services Agency, is reporting the first human case of West Nile Virus since 2008. The Mendocino County resident was infected within the county. This patient is recovering.
West Nile Virus is a disease transmitted to humans and animals through the bite of an infected mosquito. A person or animal that has been infected by West Nile Virus may have no symptoms of illness or they could become severely ill.
What are WNV Symptoms? (Symptoms can vary from severe to mild)
Severe Symptoms occur in approximately less than 1% of persons infected by WNV. These symptoms can include high fever, headache, neck stiffness, disorientation, tremors, coma, convulsions, muscle loss, numbness, paralysis and vision loss. Symptoms can last several weeks, and neurological effects may be permanent.
Mild Symptoms occur in up to 20 percent of persons infected with WNV. Symptoms include fever, headache, body aches, nausea, vomiting and sometimes swollen lymph glands or a rash on the chest, stomach and back. Person with these symptoms can feel ill for a few days, while other persons may feel ill for several weeks.
No Symptoms approximately 80% who are infected with WNV do not have any symptoms at all and do not feel ill.
Who is at Risk?
• Persons over 50 years of age are at a higher risk to develop serious symptoms if they are infected with WNV.
• Persons who spend a lot of time outdoors at dawn and/or at dusk.
• Avoid spending time outdoors at dawn and dusk when mosquitoes are most active.
• Wear long pants and long sleeved shirts when outdoors and use insect repellent. Products containing DEET appear to be more effective.
• Eliminate all sources of standing water to reduce mosquito breeding.
• Repair or replace torn screens on windows and doors to prevent mosquitoes from entering your home.
• Add mosquito fish or larvicide to small ponds that do not have fish. For use of larvicide, follow the directions on the package.
• There is a vaccine for horses to prevent WNV but no vaccine has been developed for humans.