Table 2. Treatment of black-legged ticks.

CNS, Central nervous system; POWV, Powassan virus.

No.	Pathogen	First-Line Treatment	Additional Information
1	Anaplasma phagocytophilum	Doxycycline 100 mg administered twice daily for 14 to 21 days; OR at least three days after defervescence. If co-infection with Lyme, give treatment for extra 10 days.	Potential adverse effects of doxycycline: life-threatening allergies and tooth discoloration in children < 8 years old.
2	Babesia microti	Atovaquone: 750 mg orally twice a day + azithromycin: first day: 500–1000 mg orally; subsequent days: 250–1000 mg per day OR clindamycin: 600 mg orally three times a day, or 300–600 mg IV every 6 hours + quinine: 650 mg orally every 8 hours. In addition to these, some patients, including severely ill patients, might need additional supportive care.	Quinine and clindamycin can be safely used to treat symptomatic pregnant women. Atovaquone can be administered with care in lactating women feeding infants who weigh <5 kg. Atovaquone is considered to be safe to be used in children who weigh >5 kg. Weighing the benefits and risks, azithromycin can be administered to pregnant and lactating women with caution. From 6 months to 16 years of age, azithromycin is considered a safe drug to treat Babesiosis. Benzyl alcohol is present in the parenteral form of clindamycin, which is known to cause “Gasping Syndrome” in premature infants.
3	Borrelia burgdorferi	If >8 years old with early, localized sickness: doxycycline 100 mg orally twice daily OR doxycycline 200 mg once daily for 10 days. Patient < 8 years old: amoxicillin 500 mg orally three times daily for 14 days OR cefuroxime orally three times daily for 14 days. If the person is allergic or intolerant to doxycycline, amoxicillin, and cefuroxime, they can be given macrolides: azithromycin, clarithromycin, or erythromycin. However, these drugs are of lower efficacy. People undergoing macrolides treatment should be monitored. Pregnancy: ceftriaxone. Carditis or CNS involvement: ceftriaxone OR doxycycline. The ocular feature of zoonotic disease: topical steroids + IV cephalosporin.	Post-treatment, Lyme disease syndrome is experienced by some patients. Antibiotics do not resolve these symptoms.
4	Bourbon virus	No medications; only symptomatic treatment.	-
5	Powassan virus	No specific medications. Severe disease, supportive treatment with respiratory support, intravenous fluid steps to reduce cerebral edema. POWV neuroinvasive disease: treated with high-dose corticosteroids. POWV encephalitis treated with IVIg.	-
6	Ehrlichia muris eauclarensis	Doxycycline 5-10 mg/kg every 12 hours for 5-7 days.	-
7	Borrelia mayonii	Doxycycline 100 mg orally twice daily or 200 mg once daily for 10 days.	-
8	Borrelia miyamotoi	Tick-borne relapsing fever (TBRF): Adults: a 7-day course of oral or parenteral of chloramphenicol (500 mg) 6 hourly daily for 7 days OR doxycycline (100 mg) twice daily for 7 days OR erythromycin (500 mg) 6 hourly daily for 7 days OR tetracycline (500 mg oral/250 mg parental) 6 hourly daily for 7 days OR parenteral penicillin G 60,000 IU daily for 7 days. Children < 8 years or pregnant women: penicillin G or erythromycin.	Jarisch–Herxheimer reaction with hypotension, tachycardia, chills, rigors, diaphoresis, and marked elevation of body temperature. Partial agonist meptazinol seems to reduce the severity of these symptoms due to Jarisch–Herxheimer's reaction; death is also reported as this reaction’s complication secondary to cardiovascular collapse.