RENO — The first human case of West Nile Virus (WNV) recently reported by the California Department of Public Health serves as a reminder that mosquito activity can lead to serious illness. WNV is spread through the bite of infected mosquitoes, which acquire the virus by feeding on infected birds. The illness is not spread person to person through casual contact.
Fifteen California counties have reported the virus is present in the mosquito population. The Washoe County Health District maintains and tests several sentinel flocks of birds to monitor for WNV. At this time no sign of the virus has been detected in those flocks. Adult mosquito collection surveillance conducted by the Vector-Borne Diseases Program has also indicated no sign of WNV; however, according to local health officials, WNV has been detected in our health district every year, and with the reduction in the number of abatement applications due to funding cuts, it may be only a matter of time until we see WNV in our area.
The risk of serious illness to most people is low. However, some individuals can develop a serious neurologic illness such as encephalitis or meningitis. People 50 and older have a higher chance of getting sick and are more likely to develop complications. Recent data also indicates that those with diabetes or hypertension are at greatest risk for serious illness. Many people with WNV will have no symptoms or very mild clinical symptoms. These can include fever, headache, body aches, nausea, vomiting, swollen lymph glands or a skin rash on the chest, stomach and back.
To reduce chances of contracting the virus, people should remember:
• Clear areas around your home of any free-standing water that may become a mosquito breeding-ground;
• Mosquitoes bite in the early morning and evening so it is important to wear proper clothing and 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 2 months of age and older.
• Make sure that your doors and windows have tight-fitting screens to keep mosquitoes out. • Repair or replace screens with tears or holes; and,
• Vaccinate horses for WNV.
In Washoe County WNV-related illnesses were first seen in 2003. The largest number of cases ever reported in Washoe County was 17 WNV cases in 2006. Only one case of WNV was reported in Washoe County in 2011. The Washoe County Health District’s Communicable Disease Program investigates all reported cases of diseases like WNV and presents those cases in the Communicable Disease Weekly Report. Residents are asked to report night-time mosquito activity to the District Health Department at 328-2434.
More information on WNV and the Washoe County Health District’s Vector-Borne Disease Prevention Program can be found at www.washoecounty.us/health/ehs/vbdp.html.