Lincoln, Neb. – The latest Vector-Borne Disease Surveillance report released on September 16 reported a high number of positive West Nile Virus (WNV) samples detected in Nebraska’s mosquito population. 73 positive mosquito pools have been detected out of 795 (9.2%) tested so far in the 2022 season. This is the highest number of positive mosquito pools since 2018.
Mosquito pools are samples of mosquitoes collected from across the state pooled together according to species, collection date, and collection location and tested for WNV. Historically, metrics calculated from positive mosquito pool detections has correlated with human disease cases. Due to the significant increase in the number of detected WNV positive pools, the Nebraska Department of Health and Human Services (DHHS) highly encourages Nebraskans to take preventative steps to avoid mosquito bites.
WNV is a disease spread to people through the bite of an infected mosquito. In Nebraska, it is spread by the Culex species of mosquitoes. Cases of WNV occur during mosquito season, which begins in the summer and continues through fall. Anyone can get infected with WNV, but residents can reduce their risk by taking the steps below.
Use Insect Repellent
Use Environmental Protection Agency (EPA)-registered insect repellents with one of the active ingredients below. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.
- DEET
- Picaridin (known as KBR 3023 and icaridin outside the US)
- IR3535
- Oil of lemon eucalyptus (OLE)
- Para-menthane-diol (PMD)
- 2-undecanone
Wear long-sleeved shirts and long pants
- Use 0.5% permethrin to treat clothing and gear (such as boots, pants, socks and tents) or buy permethrin-treated clothing and gear.
- Permethrin is an insecticide that kills or repels mosquitoes.
- Permethrin-treated clothing provides protection after multiple washings.
- Read product information to find out how long the protection will last.
- If treating yourself, follow the product instructions
- Do not use permethrin products directly on skin.
Take steps to control mosquitoes indoors and outdoors
- Use screens on windows and doors. Repair holes in screens to keep mosquitoes outdoors.
- Use air conditioning, if available.
- Stop mosquitoes from laying eggs in or near water.
- Once a week, empty and scrub, turn over, cover, or throw out items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpots, or trash containers.
- Check for water-holding containers both indoors and outdoors.
Most people (80%) who become infected with West Nile virus do not develop any symptoms. About 20% of people who are infected develop mild symptoms and recover completely, but fatigue and weakness can last for weeks or months. Less than 1% of people who are infected develop a severe illness affecting the central nervous system (neuroinvasive). Of the neuroinvasive cases, approximately 10% are fatal.
Severe illness can occur in people of any age; however, people over 50 years of age are at greater risk for severe illness if they are infected. People with compromised immune systems are also at greater risk.
Mild signs and symptoms
- Fever
- Headache
- Body aches
- Skin rash and
- Swollen lymph glands
Severe signs and symptoms
- High fever
- Headache
- Neck stiffness
- Stupor
- Disorientation
- Coma
- Tremors
- Occasional convulsions
- Paralysis
More information about WNV and risk reduction can be found at https://dhhs.ne.gov/pages/