This year, people are seeking emergency care for the highest level of tick bite since 2017, and reported cases of Lyme disease have continued to rise over the years, according to data from the Centers for Disease Control and Prevention.
Experts say the increase is driven by warmer temperatures due to climate change and the widening presence of mites in more parts of the US and Canada.
“When we first started this (in the mid-1980s), there were few cases of Lyme disease reported in Canada. At this point, Lyme disease is pretty well established in Canada,” said Dr. Thomas Daniels, director of the Louis Calder Centre, Biological Field Station at Fordham University.
According to the U.S. Environmental Protection Agency, when temperatures exceed 45 degrees Fahrenheit, deer mites carrying Lyme disease are mostly active.
“I like being in a humid area, not in a humid area,” Daniels said. “If you sample on grass burned in the sun all day, you won’t find any mites. You’ll go 20 feet into the woods where it’s in the shade, the temperature is generally lower and there are more ground covers and you’ll find mites.”
The threat from mites and mosquitoes that promote the transmission of diseases such as the West Nile, dengue fever and malaria is already increasing.
“Because of the human effects on the climate, temperatures are already more suitable for infection with diseases in the US and North America due to the rise in temperatures we have already seen,” Dr. Erin Mordecai, an associate professor of biology at Stanford University, said in a news briefing Monday.
And while climate change has contributed to expanding mites’ habitat, it is not the only driver. Human changes in the landscape also form where mites are found.
“That’s not one factor by any means, right?” Dr. Jean Tsao, a professor at Michigan State University, is studying disease ecology, said in a news briefing. “In the US, most of the range changes are likely due to land use changes that affect wildlife communities. Also, management of wildlife populations such as whitetail deer. These play a major role in many of these many mites.”
Deer ticks are also known as black-legged mites, and are dominant mites that carry Lyme disease. In the nymph stage, at the most active stage, mites are the size of poppy species and are easy to miss. When feeding blood, they can transmit pathogens including Bacterium borrelia burgdorferi, which causes Lyme disease. This transmission occurs through the saliva of the tika and enters the host’s bloodstream during feeding.
Brian Fallon, director of the Lyme and Tick-borne Disease Research Center at Columbia University, told CNN on Friday that the infection could cause a variety of multisystem symptoms. Once in the bloodstream, bacteria can travel to various parts of the body, including the heart, central nervous system, brain or peripheral nerves.
Lyme disease can also occur in a variety of ways.
“Most people think of lyme rash as a target rash in bulls’ eyes. In fact, it’s not the most common presentation,” Fallon said. “The most common presentation is a pinkish reddish rash. But the main thing is that it expands size from a small rash to more than 5 centimeters.”
Fallon points out that some people may see multiple rashes on different parts of their body. As the disease develops without treatment, more serious symptoms may appear. Symptoms can last for months or years, Fallon said.
“It is recognized primarily by the rash early on. If you are lucky enough to see it, then it is recognized by symptoms such as neurological symptoms that can manifest as facial paralysis or meningitis. You may have cardiac symptoms such as kinetic pit or slow rhythm. Muscle pain and fatigue.
“It can be very debilitating,” he said.
Daniels said there are measures that can be taken to reduce the chance of a tick bite, but there are no complete preventive measures. He said the most important protection against Lyme disease is removal of mites as soon as possible.
“The key is to remove the mites as quickly as possible. None of these (tick-borne) pathogens are transmitted very quickly, but they can be transmitted in just 15 minutes. However, the infection rate in (humans) is very low,” Daniels said. “In Lyme disease, there is a window of opportunity for 24-48 hours, because it takes time for the tick to actually prepare the feeding to transmit the bacteria.”
Daniels encourages people to wear more clothes in the summer. “The more you can keep mites on the outside of your body rather than on the skin, the less likely you are to find a place to attach.” Clothes can also be treated with permethrin, an insecticide that repels mites.
When hiking, Fallon advises people to stay on the trail as ticks roam around leafy areas and tree mountains. Daniels advises people to do a “tick check” for themselves and each other if they are in an area with mites.
“It helps because mites may go behind your knees. Or they bite your back and can’t see your back and reach your back. They shower at the end of the day.
If the ticks are attached for a long period of time, Fallon says they are gradually “blowing out as big as raisins.” If a mites are found, experts will recommend using tweezers to remove the mites from under the body.
“Don’t try to burn it with cigarettes. Don’t try to put anything toxic in. Remove it with tweezers,” he said.
