Onondaga County Health Commissioner Dr. Kathryn Anderson announced today that lab results show the presence of the Jamestown Canyon virus (JCV) and Flanders Virus (FLAV) in mosquitoes trapped in Onondaga County. The finding was the result of the Health Department’s mosquito surveillance and control program which collects and tests mosquitoes for viruses. There have been no known human cases in Onondaga County.

The JCV virus can be spread to people by infected mosquitoes. Many people have no symptoms and do not get sick, but some have symptoms such as fever, headache, fatigue, cough and sore throat. Very rarely it can develop into encephalitis. The best way to reduce your risk of infection is by avoiding mosquito bites. FLAV has not been known to cause disease in humans, however, the presence of the virus may be an early predictor of West Nile Virus (WNV) transmission in the mosquito population.

The Health Department will report any future findings of these and other viruses as part of their weekly mosquito pool testing, available on their website. The Health Department’s Mosquito Control program uses larvicides (insecticides) to control mosquito breeding in standing bodies of water. The decision to spray each year is based on several factors including, but not limited to, the presence of certain viruses and the number of mosquitoes found in mosquito surveillance traps. All spraying decisions are made with assistance from the New York State Departments of Health (NYSDOH) and Environmental Conservation (NYSDEC)

Personal Protection Measures
The presence of these viruses is an important reminder that there are steps everyone should take to protect themselves from mosquito bites during outdoor activities:

• Wear shoes, light-colored socks, long pants, and a long-sleeved shirt. Tuck in your shirt and tuck pant legs into boots or socks.
• Consider using insect repellents containing DEET, Picaridin, IR3535, oil of lemon eucalyptus, and other products that have been approved by the Environmental Protection Agency (EPA). Use this EPA search tool to help you choose the repellent product that is right for you, and follow the manufacturer’s instructions on proper use for safety and effectiveness. Insect repellents should be applied only to intact skin or over clothing. Do NOT apply DEET or Picaridin directly onto children’s skin (apply to your own hands and then put it on the child). Repellent should not be used on babies younger than 2 months old.
• Mosquito repellent diffusers repel mosquitoes in the air and can be quite effective at reducing the number of mosquitoes in your immediate area.  Diffusers, alone or in combination with repellants applied to the skin, may offer additional protection.
• Treat clothing and gear with products containing 0.5% permethrin. Permethrin can be used to treat boots, clothing, and camping gear and remain protective through several washings. Alternatively, you can buy permethrin-treated clothing and gear.

Mosquito-Proof Your Home
It is also important to mosquito-proof your home by replacing or repairing broken screens and getting rid of standing water where mosquitoes breed. Keep your property free of standing water by cleaning clogged rain gutters; turning over wheelbarrows and wading pools when not in use; changing water in birdbaths every four days; properly maintaining swimming pools, outdoor saunas, and hot tubs; draining water from pool covers; and, using landscaping to eliminate low spots where standing water accumulates.

Signs and Symptoms of Jamestown Canyon Virus
According to the CDC as of July 9, 2024, no human disease cases of JCV have been reported this year; there were 26 cases in the US in 2023. JCV accounts for about 1% of mosquito-borne viral diseases in the U.S.  Although many people infected with Jamestown Canyon virus do not have symptoms, the virus can cause severe disease.

• For people with symptoms, the time from mosquito bite to feeling sick ranges from a few days to 2 weeks.
• Initial symptoms can include fever, fatigue, and headache. Some people also have respiratory symptoms such as cough, sore throat, or runny nose.
• JCV can cause severe disease, including infection of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis).
• Symptoms of encephalitis or meningitis include stiff neck, confusion, loss of coordination, difficulty speaking, or seizures.
• About half of patients reported with Jamestown Canyon virus disease are hospitalized.
• Deaths associated with Jamestown Canyon virus infection are rare.

Contact your healthcare provider if you have recently been bitten by a mosquito and are experiencing flu-like symptoms.

More Information and Resources
For the weekly mosquito pool test results and for more information about personal protection measures against mosquitoes, visit www.ongov.net/health/env/mosquitoes.html or contact the Onondaga County Health Department’s Division of Environmental Health at 315. 435.1649.

For more information about Jamestown Canyon virus and mosquito-borne illnesses, visit:
https://www.cdc.gov/jamestown-canyon/symptoms-diagnosis-treatment/index.html
https://www.cdc.gov/mosquitoes/about/index.html