Ada County became the fifth Idaho county in southwest Idaho to discover West Nile virus in mosquito pool testing this summer, providing a good reminder for people to “fight the bite” to stay healthy.
Besides the recent positive test in Ada County, the four other Idaho counties with confirmed WNV activity include Canyon, Gem, Payette and Owyhee counties. No human cases have been reported so far this year, but last year 13 human cases of West Nile infection were reported, with five people suffering from potentially serious neuroinvasive infections. A total of 15 Idaho counties detected WNV activity during 2015.
WNV is usually contracted from the bite of an infected mosquito; it is not spread from person-to-person through casual contact. Symptoms of infection often include fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach, and back. In some cases the virus can cause severe illness, especially in people over the age of 50.
To reduce the likelihood of infection, avoid mosquitoes, particularly between dusk and dawn when they are most active. In addition, you should:
- Cover up exposed skin when outdoors and apply DEET or other EPA-approved insect repellent to exposed skin and clothing. Carefully follow instructions on the product label, especially for children.
- Insect-proof your home by repairing or replacing screens.
- Reduce standing water on your property; check and drain toys, trays or pots outdoors which may hold water.
- Change bird baths and static decorative ponds weekly as they may provide a suitable mosquito habitat.
No deaths were reported last year, however, it is difficult to predict the impact WNV will have from year-to-year. In 2006, Idaho led the nation in West Nile human illnesses with almost 1,000 infections, which contributed to 23 deaths.
WNV does not usually affect domestic animals, including dogs and cats, but it can cause severe illness in horses and certain species of birds. Although there is no vaccine available for people, there are several vaccines available for horses. People are advised to keep their horses vaccinated annually.