How to identify if a patient has been infected with other Ixodes transmitted pathogens in addition to B burgdorferi?
I. scapularis can transmit other pathogens at the time it transmits B. burgdorferi . The two most common are Babesia microti (babesiosis) and Anaplasma phagocytophilum (human granulocytic anaplasmosis). I. scapularis can also transmit B. miyamotoi , which causes relapsing fever, headache, myalgia, arthralgia, and fatigue. Unlike in Lyme disease, these individuals will not have a rash. Any patients with suspected Lyme disease who have leukopenia or thrombocytopenia should be investigated for coinfection with one of these pathogens.
Babesiosis causes fever, headaches, myalgias, hemolysis, thrombocytopenia, and elevated liver enzymes. Intraerythrocytic organisms may be seen on peripheral blood smear. Treatment requires therapy with azithromycin plus atovaquone, or IV clindamycin plus oral quinine for 7 to 10 days. Human granulocytic anaplasmosis causes fever, headache, arthralgias, leukopenia, and thrombocytopenia. If it is misdiagnosed as Lyme disease, it still responds to doxycycline but not to amoxicillin therapy. Treatment includes doxycycline 100 mg twice daily for 10 days. Patients allergic to or unable to take doxycycline (pregnant, breastfeeding, children of <8 years of age) should be treated with rifampin 300 mg twice daily (or 10 mg/kg twice daily for children) for 7 to 10 days.