Lyme disease: What to do if you get bitten by a tick

Lyme disease—the illness that struck Justin Timberlake—is an infection transmitted by ticks of the genus Ixodes ricinus , known in Europe as the "woodland tick" or "sheep tick" (not the dog tick). The pathogen is a bacterium, Borrelia. The disease is difficult to diagnose because symptoms can appear after many months, making it difficult to trace them back to a tick bite from a long time ago, which is sometimes undetected because it is painless.

The unmistakable signs

There are, however, signs to watch out for after a bite. "And they're also quite easy to spot," explains Enea G. Di Domenico , Coordinator of Experimental Scientific Activities at the Microbiology and Virology Laboratory, San Gallicano Dermatological Institute, IRCCS, IFO, Rome, "because a lesion appears at the bite site. This is what we call erythema migrans, a kind of target with a red center, a clear halo around it, and then another red circle around it. It tends to widen, making it visible. This is the first clue, which should lead us to see a doctor who will diagnose and prescribe preventative antibiotic therapy. In 80-90% of cases, the risk of disease is averted for two reasons: the first is that we administer the antibiotic but we don't know if the bacteria was actually in the tick's intestine, because obviously not all ticks are infected; the second is that fortunately, this bacteria isn't resistant to antibiotics, which are therefore effective."

Who gets sick instead

Then there are 10-20% of cases in which people do get sick. "It's usually because antibiotic therapy is started late," Di Domenico continues, "or because we don't notice the bite because it's perhaps on our back or head, or because we're dealing with strains that can tolerate the antibiotic thanks to a biofilm that protects the pathogen." Researchers at San Gallicano, in collaboration with Sapienza University, the University of Ljubljana, and the Lyme Association Italy, recently coordinated and published a study on these very strains in Frontiers in Cellular and Infection. Microbiology-Veterinary and Zoonotic Infection. The study used advanced genetic analysis techniques and antibiotic testing to discover that when the bacteria Borrelia afzelii and Borrelia garinii —the main agents of Lyme disease in Europe—form protective biofilms, commonly used drugs like ceftriaxone and doxycycline lose much of their effectiveness. "This contributes to making Lyme disease persistent and difficult to treat with traditional therapies," explains Di Domenico, the study's scientific director. But it also opens the door to new interventions.

The symptoms

But let's get to the symptoms. After erythema migrans, after a few weeks (which in some cases can extend to months), skin and early neurological disorders can develop, affecting the joints, nervous system, and internal organs. The disease can become chronic. "It's actually very difficult to diagnose Lyme disease," Di Domenico continues, "but it's achieved by elimination, and this is precisely why conducting studies is so difficult. There are no classic symptoms, and it's difficult to connect the symptoms to a bite perhaps from a year earlier. Treatment doesn't rely on anything specific; antibiotics are prescribed in cycles, some in the United States even for very long periods, and then individual symptoms are treated. It's certainly a debilitating disease with sometimes severe effects."

Prophylaxis

Genetically engineered Lyme borreliosis vaccines are available in the United States, but it's unknown how long the immunity lasts. In any case, the vaccines are recommended only for people aged 15 to 70 who live or work in areas infested with ticks infected with Lyme borreliosis agents. These agents are not the same as those circulating in Europe, which is why they are not used in Italy and other European countries.

Precautions

The Istituto Superiore di Sanità recommends taking precautions when going on mountain trips (ticks love the cool and are therefore not very common in the South): dress appropriately, and at the end of the excursion carefully inspect your skin,

Especially soft, warm areas, such as the knee, elbow, armpit, groin, and even the back, are more attractive to ticks. Always check your clothing to promptly remove any intruders. There are also products on the market that discourage tick attacks, such as diethylammonium chloride and Icaridin or KBR3021.

How to remove a tick

If you notice a tick embedded in your skin, remove it promptly: just use tweezers and disinfect. Be careful not to crush the insect, as this will increase the risk of infection. Never touch the tick with bare hands: wear gloves and wash your hands thoroughly afterwards. Then, make sure the removed tick is intact and that no parts remain inside the skin. If necessary, use a sterile needle to remove the remaining tick. The ISS also recommends "preserving the extracted tick in a bottle of 70% alcohol to identify any pathogens, if necessary, and to inform your doctor of the location where it was found if symptoms develop. Prohibited "Old wives' remedies", such as sprinkling the tick with alcohol or oil or other substances: this does not make extraction easier and can even push the insect to burrow further into the host".