We are currently in the middle of mosquito season, Humid environments Mosquitoes’ itchy bites increase the risk of spreading mosquito-borne diseases to humans.
This week, Maine officials warned residents of the town of Orono that mosquitoes in the area Carries the Jamestown Canyon virusAccording to the Maine Department of Health and Human Services, the virus was first identified in the state as being transmitted from mosquitoes to humans in 2017. The Maine Center for Disease Control and Prevention told USA Today that this was the earliest a mosquito has tested positive for the virus this year.
“This has gotten our ears up and gives us hope that we’re probably going to have a more active mosquito season this year,” said Megan Porter, public health educator at the Maine CDC.
Maine health officials said the virus, which scientists consider a new public health threat to humanity, very rarely infects humans but can cause meningitis and other severe neurological illnesses that can be fatal.
“Severe symptoms can progress quickly and become severe,” Porter said..
West Nile virus and Dengue virus Experts say St. Louis encephalitis is much more widespread and likely transmitted to humans by mosquitoes that carry it. Doctors and scientists are also keeping a close eye on St. Louis encephalitis this summer, a mosquito-borne disease that can cause encephalitis if severe.
Shannan Rossi, a professor of biology and immunology at the University of Texas Medical Branch at Galveston, said more people will likely get the illness as hot, humid days increase in many parts of the country for the rest of the summer.
“As the summer continues, we’re going to see more and more of these local cases, but that’s to be expected. We see these every year,” Rossi said.
Here’s what you need to know about the mosquito outlook for the next few months, according to experts.
Jamestown Canyon virus infects mosquitoes in Maine
Maine health officials say recent mosquito testing near the town of Orono in Penobscot County is the first in the state to do so. First positive test result Viruses are the biggest threat this year.
No cases of human infection with the virus have been reported this year, with the last case occurring in 2021, Porter said.
The virus occurs naturally in mosquitoes that live in northern U.S. states and southern Canadian provinces, Rossi said. In Maine, the virus is most commonly transmitted by “snow thaw mosquitoes,” which congregate around the first melting snow each spring, Porter said. Overall, several species of mosquitoes transmit the virus, but the number of people infected by mosquito bites is “incredibly small,” Rossi said.
In New York state, researchers found that the prevalence of Jamestown Canyon virus in mosquitoes was “Significantly largerCompared to 2001-2011, from 2012 to 2022,
“You don’t hear much about” the virus infecting humans, Rossi said, “but the Jamestown Canyon virus is so vague, it always shows up in mosquito tests if you look for it.”
People with the virus may not show any symptoms, but if they do, they may experience vomiting, neck stiffness, loss of coordination and, in severe cases, brain swelling and meningitis, according to the Maine Department of Health and Human Services.
In 2018, a 56-year-old man with chronic encephalitis caused by the virus died, according to the Maine CDC.
Harvard researchers announced that post-mortem examination of the man’s spinal fluid “revealed widespread neuropathological abnormalities.” report Published in 2021.
The Maine Department of Health and Human Services said in a news release that after three mosquito tests in the state in 2023 tested positive for the Jamestown Canyon virus, there have been no cases of mosquitoes transmitting the virus to humans.
“Even if we continue to find the virus in mosquitoes, that doesn’t necessarily pose a big risk to humans,” Rossi said, “but it’s still a concern that the virus transmitted by mosquitoes could be in our backyard.”
Nationwide, no human cases of St. Louis encephalitis have been reported this year, according to the CDC.
West Nile virus is widespread, and dengue fever could spread even further
At first It spread to the United States in 1999West Nile virus has now been found in mosquitoes in all 48 contiguous states, Rossi said.
So far in 2024, there have been 15 cases in 11 states of mosquitoes transmitting the virus to humans, according to the federal Centers for Disease Control and Prevention (CDC). The 15 cases are evenly distributed across Texas, Mississippi, Arkansas, Tennessee, North Dakota, Nebraska, Kansas, Arizona, Michigan and Maryland, according to the CDC.
this is The summer is expected to be hot Rossi said higher humidity than normal could lead to an increase in cases of West Nile virus.
“What worries me is that the summers are getting hotter and longer than usual, which means mosquito season will last longer than before,” said Rossi, 43.
Cases of dengue fever spike In Puerto Rico, the number of cases has reached 1,700 this year, prompting island officials to declare a health emergency. The rise comes just after the CDC warned that the number of cases in the Americas had topped 1,000. Twice the cases The number of cases in the first half of 2024 will increase to 9.7 million and 4.6 million cases compared to the total number of cases last year.
South Florida has historically been a hotspot for dengue in the United States, with nine locally acquired cases in 2024, according to the CDC’s tracking system. No locally acquired cases of dengue have been reported in the United States outside of Florida, according to the CDC, but 15 cases have been reported in the U.S. Virgin Islands.
The dengue cases in other U.S. states were identified overseas, with dozens of cases reported in New York, Massachusetts, California and Illinois, according to the CDC.
But Rossi said doctors are keeping a close eye on local cases of the dengue virus, which is spreading in North Florida.
“As temperatures get warmer and warmer, it makes it easier for mosquitoes to move into places they haven’t been before, so we have to be concerned that that opens up more areas where dengue can be transmitted,” she said, referring to Georgia and the Carolinas, which have already reported 40 confirmed cases of travel-related dengue, according to the CDC.
How can I prevent West Nile, Dengue, and Jamestown Canyon Virus?
Rossi said mosquitoes that carry the West Nile virus bite at dawn and dusk, so staying indoors during those times is key to preventing infection.
Rossi says dengue-carrying mosquitoes are more likely to congregate near standing water close to people’s homes, such as in damp backyards, and keeping windows closed when possible is a good precaution to avoid contact with mosquitoes, he said.
Other than that, bug repellent and proper clothing can help protect you from insect bites that may carry viruses, including the Jamestown Canyon virus.
“I know this is hard to say in 95-degree weather, but wear long sleeves,” Rossi said.
