Lyme disease ticks have taken over half of the United States counties, health experts have recently warned.
The alarming conclusion was presented in the Journal of Medical Entomology, as part of a study led by Dr. Rebecca Eisen, research biologist at the Centers for Disease Control and Prevention.
Experts carried out an extensive analysis across the nation’s 3,110 counties, reviewing reports keeping track of the blacklegged tick population at state and county level, ever since the year 1996.
The purpose was to identify counties where these vectors transmitting Lyme disease had already been “established”. In other words, scientists focused on areas where sightings throughout the year had involved a minimum of 6 such deer ticks, or at least 2 stages of these arachnids’ life cycles had been reported.
It was determined that Lyme disease ticks (scientifically known as Ixodes scapularis) have greatly expanded their habitat in the last two decades.
Back in 1998, they had been spotted in just around 30% of the nation’s counties, but now they are populating approximately 45.6% of these administrative regions.
Even more worryingly, the number of counties where blacklegged ticks are now an established species has grown twofold ever since 1998.
Apparently, the greatest upsurge in the number of Lyme disease ticks has been identified in the northern, upper Midwest and northeastern part of the United States, especially in counties such as Ohio, Vermont, Minnesota, New York and Wisconsin.
Researchers speculate that there are several reasons why these blood-sucking parasites have been experiencing such a dramatic growth.
One contributing factor is global warming, given the fact that the small, yet dangerous arachnids tend to favor warm and moist areas, which are ideal breeding grounds for them.
Other drivers of this unprecedented rise in the number of ticks have been the ever-expanding deer population, coupled with reforestation.
The vectors of the Borrelia bacteria, which causes Lyme disease, often thrive by latching onto white-tailed deer, and feeding on their blood, although there are times when they choose other hosts such as small rodents, house pets and even humans.
At the beginning of the 20th century, deer had been brought to the brink of extinction as a direct consequence of over-hunting and deforestation, but now their numbers have been growing, so Lyme disease ticks benefit once again from a steady and rich food supply.
The fact that these tiny creatures are experiencing such a population boom is quite problematic, since Lyme disease can have a dramatic impact on human health.
The official incidence of this condition is of around 30,000 new cases per year, although researchers speculate annual infection rates are actually more than ten times higher, at 329,000.
Under normal conditions the infection caused by Borrelia bacteria has relatively mild manifestations, like migraines, bull’s-eye rashes, fatigue, fever and muscle pain.
These symptoms can usually be quickly and effectively alleviated by conventional antibiotics, such as amoxicillin, cefuroxime and doxycycline.
However, in some cases, when the disease isn’t promptly addressed in its earliest stages, it can result in much more serious conditions. For instance, it can lead to neurological issues, such as facial palsy, meningitis and encephalitis.
It can also severely impact the joints, the brain, the eyes and the heart, causing debilitating pain, arrhythmia, insomnia, feelings of numbness and tingling in the limbs, and even malaise and depression.
Given these risks, experts from the Centers for Disease Control and Prevention urge people to take greater precautions so as not to contract Lyme disease.
For instance, it’s recommended to steer clear of high-grass regions, which can be found not just at the countryside or in the middle of the forest, but also in parks or other green spaces.
Moreover, long-sleeved clothes and long pants should be worn, and any exposed skin should be protected using insect repellents with a concentration of DEET between 20 and 30%. Also, equipment and garments should be carefully sprayed with another insecticide called permethrin.
Last but not least, upon returning indoors after exploring wooded or bushy areas individuals should take a shower or a bath immediately, and make sure that there are no ticks on their bodies, or on their clothes, tools or pets.
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