Cases of Rare Mosquito-Borne Virus Spring Up in Two US States

A relatively rare mosquito-borne virus has hit a couple of US states this summer, and it has health officials urging individuals to take the proper precautions against mosquito bites. The disease in question? Jamestown Canyon virus (JCV).

Spread to individuals through the bite of an infected mosquito, JCV is an orthobunyavirus in the California serogroup known to be capable of causing “acute febrile illness, meningitis, or meningoencephalitis.” A recent analysis confirmed 31 cases of JCV in the United States between 2000 and 2013, spanning 13 states. The geographic range of JCV remains unclear; cases occurred in western, Midwestern, northeastern, and southern states from 2000 to 2013. JCV infections tend to occur from spring to early fall, with about half of reported cases resulting in hospitalization. The good news is, no associated deaths have been reported to date.

On July 13, 2017, the Maine Center for Disease Control & Prevention, an Office of the Maine Department of Health and Human Services, confirmed a case of the virus in an adult from Kennebec County. The infected individual reportedly had symptom onset in early June 2017. Although the case required hospitalization, the individual has since returned home to recover.

Health officials in Maine worked on promoting awareness of the relatively rare disease, as well as other arboviruses, such as West Nile virus (WNV), that tend to be prevalent this time of year.

“This case reminds us all that mosquitoes are more than a nuisance, but they also carry disease,” state epidemiologist Siiri Bennett, MD, commented in the official press release. “Prevention is key if Mainers are going to protect themselves from mosquito-borne diseases.”

Since July, a local news hub, Bangor Daily News, has reported 2 more confirmed cases of the virus in the state. Dr. Bennett was reported to have said that the significance of the 2 additional cases is “hard to pin down.” Since the illness is not incorporated into routine testing, she suspects that there are even more cases of the virus in Maine that have yet to be identified.

“There’s so much we don’t know about this virus,” she admitted. “It’s alarming to know that it’s out there, that there’s a virus you need to be aware of.”

Meanwhile, in New Hampshire, the Department of Health and Human Services has just identified their first case of the virus in a Hanover resident in late August 2017.

“Jamestown Canyon virus is one of several viral infections that can be transmitted through the bite of an infected mosquito in New Hampshire,” state epidemiologist Benjamin Chan, MD, reported in the official press release. “It is an uncommon infection to be found, but similar to WNV and Eastern equine encephalitis, it also has the potential to cause serious health complications including central nervous system infection. Because of the risk for various infections from mosquitoes, we want to remind people to take steps to avoid mosquito bites and remove areas of standing water around their homes where mosquitoes might breed and reproduce.”

Preventing this illness depends on 2 factors: avoiding mosquito bites and removing standing water around the home. Avoiding outdoor activities at peak feeding times for mosquitoes, wearing long sleeves and long pants, and using insect repellant are all good ways to avoid bites. Removing or emptying any containers that are outside that can collect water, changing birdbaths once a week, checking gutters and frequently removing leaves that collect there, and filling tree holes with dirt or sand can all work to prevent mosquito breeding.

To stay up-to-date on JCV infections in the United States, be sure to visit the Contagion ^® Outbreak Monitor.