Every year as the weather warms, the mosquito population booms and so does the potential for the diseases mosquitoes carry. In response, Lane County Environmental Health, a section of Lane County Public Health, is conducting active mosquito surveillance this summer for West Nile Virus and Zika Virus. Traps are used to collect mosquitoes from different active mosquito areas in Lane County weekly. The mosquitoes are then sorted by species and sent to the OSU Veterinary Diagnostic Laboratory to test for West Nile Virus and Zika Virus. This surveillance is part of the Oregon Health Authority West Nile Virus Surveillance Project and Zika Virus Surveillance activities. 

“While cases are rare, this is a fundamental part of our ability to monitor the spread of mosquito-borne illness in Lane County,” said Senior Public Health Officer Patrick Luedtke, M.D. “Our surveillance will allow us to be responsive if mosquito populations show a proliferation of disease, as well as work with our partners in other counties and states to track the spread.”

West Nile Virus:

West Nile Virus (WNV) is a seasonal virus that flares up in the summer and continues into the fall until temperatures consistently fall below 50 degrees. While WNV is rare, it is easily transmitted and can cause serious illness. The virus is spread primarily through infected mosquitoes and typically after the insect has bitten a bird. Early symptoms include fever, headache, body aches, and skin rash.

Zika Virus:

Zika is a virus usually spread by mosquitoes. Zika can also spread through sexual activity with an infected person, even if that person shows no sign of illness. We know of only two types of mosquitoes that spread Zika. Those mosquitoes have not been found in Oregon. We do not know if Oregon’s mosquitoes could spread Zika if it were introduced to our mosquito population. Most people who have Zika do not show signs of illness. Those who do show signs of Zika may have a rash, fever, joint pain and redness of the eyes. Zika symptoms are usually mild. Serious illness that creates a need for hospital care is uncommon. Zika can cause birth defects when pregnant women are infected. 

Preventive Tips:

• When outdoors, use repellents containing DEET; DEET-free alternatives, such as, lemon eucalyptus oil and citronella, are also effective.
• Mosquito species that carry WNV are the most active from dusk to dawn.  Mosquito species that carry Zika are most active during daylight hours. Use insect repellent and wear clothing that provides extensive cover or stay indoors during this time.
• Inspect your home for any openings that mosquitoes could use to enter and make sure all windows are covered with protective screens.
• Empty any standing water, such as flower pots, buckets, barrels, etc.
• Change water in pet dishes and bird baths weekly.

Mosquito control

Limiting exposure to mosquitoes is fundamental to help prevent the spread of WNV. Reducing the amount of standing water available for mosquito breeding is a key element in mosquito control. Other mosquito control guidelines include:

• Dispose of tin cans, plastic containers, ceramic pots or similar water-holding containers.
• Remove all discarded tires.
• Drill holes in the bottom of recycling containers left outdoors.
• Clean clogged roof gutters.
• Turn over plastic wading pools when not in use.
• Turn over wheelbarrows and don’t let water stagnate in birdbaths.
• Aerate ornamental pools or stock them with fish.
• Clean and chlorinate swimming pools when not in use.
• Use landscaping to eliminate standing water.
• Utilize mosquito dunks or torpedoes for larvae control in standing water that cannot be eliminated.
• Utilize mosquito traps when necessary.