Officials announce confirmed case of Jamestown Canyon Virus, warn public to protect themselves

PROVIDENCE, RI – The Rhode Island Department of Health is reporting a confirmed case of Jamestown Canyon Virus in a Rhode Island resident. Laboratory testing confirming the diagnosis was conducted by the Centers for Disease Control and Prevention. The person who tested positive was a resident of Washington County in his 50s who developed neurological symptoms and is now recovering. JCV is spread to humans through the bite of an infected mosquito.

JCV is a mosquito-borne pathogen that can be found widely in North America, especially in the Midwest and Northeast United States. The virus circulates primarily between deer and mosquitoes, but can also infect humans. Human cases can occur from late spring through mid-fall. People can be infected and not develop any symptoms, or only develop very mild symptoms. Early symptoms can include fever, muscle aches, headaches, and fatigue. Rarely, more serious central nervous system disease, including meningitis or encephalitis, can occur.

The Rhode Island Department of Environmental Management is announcing today that the most recent round of testing of mosquito samples by the RIDOH State Health Laboratories has confirmed no positive isolations (findings) of West Nile Virus or Eastern Equine Encephalitis. DEM collected 115 pools (samples) of mosquitoes from 29 traps set statewide on July 19. Results from the 105 pools collected on July 26 are pending. Connecticut Department of Public Health reported seven WNV isolations from seven mosquito pools collected in July, and the Massachusetts Department of Public Health reported eight recent isolations of WNV in mosquito samples collected in July. This is expected at this time because mosquito-borne diseases become more prevalent as the summer season progresses. Thus far, neither Rhode Island, Massachusetts, nor Connecticut has reported any EEE findings.

WNV is much more prevalent than EEE. It became established in North America following its introduction in 1999. WNV will become more prevalent as the season progresses, so DEM and the RIDOH advise residents to reduce their exposure to mosquitoes until the first hard frost. (A hard frost is when the air and the ground freeze below 32°F for three hours or below 28°F for two hours.)

Personal protection is the first line of defense against mosquitoes that may carry WNV, EEE, or other diseases – and the most effective way to avoid infection. Residents are reminded to eliminate mosquito breeding grounds and prevent being bitten, whenever possible. The following precautions are advised:

Protect yourself

-Put screens on windows and doors. Fix screens that are loose or have holes.

-At sunrise and sundown (when mosquitoes that carry EEE are most active), consider rescheduling outdoor activities that occur during evening or early morning. If you must be outside, wear long-sleeved shirts and long pants and use bug spray.

-Use EPA-approved bug spray with one of the following active ingredients: DEET (20-30% strength); picaridin, IR3535; and oil of lemon eucalyptus or paramenthane. Always read the label and follow all directions and precautions.

-Do not use bug spray with DEET on infants under two months of age. Children should be careful not to rub their eyes after bug spray has been applied on their skin. Wash children’s hands with soap and water to remove any bug spray when they return indoors.

-Put mosquito netting over playpens and baby carriages.

Remove mosquito breeding grounds

-Remove items around your house and yard that collect water. Just one cup of water can produce hundreds of mosquitoes; an unused tire containing water can produce thousands of mosquitoes.

-Clean your gutters and downspouts so that they can drain properly.

-Remove any water from unused swimming pools, wading pools, boats, planters, trash and recycling bins, tires, and anything else that collects water, and cover them.

-Remove or treat any shallow water that can accumulate on top of a pool cover. Larvicide treatments, such as Mosquito Dunks can be applied to kill immature mosquitoes.

-Clean and change water in birdbaths at least once a week.

Best practices for horse owners

Horses are particularly susceptible to WNV and EEE. Horse owners are advised to vaccinate their animals early in the season and practice the following:

-Remove or cover areas where standing water can collect.

-Avoid putting animals outside at dawn, dusk, or during the night when mosquitoes are most active.

-Insect-proof facilities where possible and use approved repellents frequently.

-Monitor animals for symptoms of fever and/or neurological signs (such as stumbling, moodiness, loss of appetite) and report all suspicious cases to a veterinarian immediately. If you are unsure if your horse is properly vaccinated, you should consult with your veterinarian.