As the Fourth of July approaches and Oregonians head outdoors, public health officials are advising people to take general precautions against mosquitoes to avoid a possible risk of West Nile virus infection.
Historically, warm weather leads to elevated mosquito activity and the threat of West Nile virus. So far in 2016, West Nile virus has been detected in southern Washington state adjacent to the Columbia River. No human cases have been reported in Oregon.
West Nile is spread to humans through the bite of an infected mosquito. Most infected people will show little or no signs of disease. About one in five infected people may show signs of West Nile fever. People at risk include individuals 50 and older, people with immune compromising conditions, and those with diabetes and high blood pressure.
West Nile symptoms may include fever above 100 degrees and severe headache, stiff neck, mental confusion, muscle weakness, shaking, paralysis or rash. It is important that you contact your health care provider if you experience any of these symptoms. Rarely, infected individuals may develop neuro-invasive disease (infection of the brain or spinal column) that can be severe or may cause death. This is especially of concern to those who have a compromised immune system and the elderly.
The fever syndrome may last from a few days to several weeks.
"It's very easy for people to prevent bites from mosquitoes that may carry West Nile virus," said Emilio DeBess, DVM, public health veterinarian at the Oregon Health Authority's Public Health Division, who recommends that people and animals be protected against mosquito bites. "Although the risk of contracting West Nile virus is low, people can take simple precautions to keep these insects at bay if they're headed outdoors."
DeBess offers these tips:
- Eliminate sources of standing water that are a breeding ground for mosquitoes, including watering troughs, bird baths, ornamental ponds, buckets, wading and swimming pools not in use, and old tires.
- When engaged in outdoor activities at dusk and dawn when mosquitoes are most active, protect yourself by using mosquito repellants containing DEET, oil of lemon eucalyptus or Picardin, and follow the directions on the container.
- Wear long-sleeved shirts and long pants in mosquito-infested areas.
- Make sure screen doors and windows are in good repair and fit tightly.
Additional information about West Nile virus is available at the Oregon Health Authority website and from the U.S. Centers for Disease Control and Prevention with information available in Spanish and English.