Two people in Michigan test positive for the rare mosquito-borne ‘Jamestown Canyon virus’ that has a 50% hospitalization rate
Two people in Michigan test positive for the rare mosquito-borne ‘Jamestown Canyon virus’ that has a 50% hospitalization rate
Two people in Michigan have been diagnosed with a rare mosquito-borne virus — amid concerns that insect-borne diseases are becoming more common.
The Detroit patients tested positive for the Jamestown Canyon virus – the first cases of the infection in the US this year.
They would be in stable condition. But in severe cases, the disease can lead to encephalitis — or swelling of the brain — and seizures. Early warning signs are fever, headache and muscle aches.
There is growing concern that the number of infections will increase as a longer warm season extends the period in which mosquitoes are active. It comes during the first domestic outbreak of malaria in the US in decades.
Two people in Detroit metropolitan area have tested positive for Jamestown Canyon virus, state health department says
The virus is picked up by mosquitoes after they bite deer. It can then be transmitted to humans when bitten as well
The Michigan Department of Health said the patients lived in Oakland and Macomb, in the northern Detroit metropolitan area.
Health officials are urging people in Michigan to take precautions against mosquito bites.
Dr. Natasha Bagdasarian, the chief medical executive of the state’s health ministry, said: ‘It only takes one bite from an infected mosquito to cause serious illness.
“We recommend using insect repellent and wearing long-sleeved shirts and long pants if you’re outside during times when mosquitoes are active.”
She added: “It’s a good idea to take extra precautions during mosquito peak times, from dusk to dawn.”
About 17 cases of the disease are diagnosed in the US each year, with infections most likely in August and September, particularly in Midwestern states.
Several state health departments say the infection is “rare.”
About 13 cases have been reported in Michigan since 2011. The virus is most commonly detected in Wisconsin (132 cases in a decade) and Minnesota (74 cases).
The Jamestown Canyon virus is picked up by mosquitoes when they bite infected mammals such as deer and elk.
The disease can then be transmitted to humans when bitten, traveling through the body through blood vessels that cause disease.
Symptoms of the disease take about two days to two weeks to appear and can include fatigue, headache, muscle aches, and joint pain.
About half of the patients are hospitalized and a small number die. However, no American is known to have died from the infection.
In severe cases, the virus can begin to attack the membranes around the brain and spinal cord, causing encephalitis and meningitis, which can lead to neurological problems.
Doctors use a blood test to diagnose the disease, but have no targeted drugs, instead relying on IV drops and painkillers to treat infections.
The map above shows the number of cases reported by states from 2011 to 2022. Midwestern states had the most infections, although the virus remains rare
Medics have noticed a rise in the number of diagnosed Jamestown Canyon virus cases in recent years.
Between 2011 and 2012 there were about two to three per year, according to figures, but in 2021 this increased to no fewer than 32 per year.
People most likely to get infected included men who spent most of their time outdoors, where they were more likely to get a mosquito bite.
The virus is named after its place of discovery, after it was first identified in 1961 in Jamestown, Colorado.