Assessment of Anaplasma phagocytophilum presence in early Lyme borreliosis manifested by erythema migrans skin lesions.

Background: To investigate to what extent early Lyme borreliosis patients with erythema migrans are infected with Anaplasma phagocytophilum.

Methods: Three hundred ten patients from Poland with erythema migrans were included in the study. One hundred and eighty-three patients (59%) agreed to have both skin biopsy and blood samples analysed for Borrelia burgdorferi, A. phagocytophilum and 'Candidatus Neoehrlichia mikurensis', with PCR. Positive samples were confirmed with sequencing.

Results: B. burgdorferi DNA was detected in 49.7% of the skin samples and in 1.1% of the blood samples. A. phagocytophilum DNA was found in 7.1% blood samples, and in 8.2% of the skin biopsies. In four patients, A. phagocytophilum DNA was detected only in blood; in one case A. phagocytophilum DNA was found simultaneously in blood and skin, and additionally in this patients' blood Borrelia DNA was detected. In four skin samples B. burgdorferi DNA was detected simultaneously with A. phagocytophilum DNA, indicative of a co-infection.

Conclusions: A. phagocytophilum may be present in early Lyme borreliosis characterized by erythema migrans and should always be considered as a differential diagnostic following a tick bite and considered in treatment schemes, as these differs (in early stage of Lyme borreliosis doxycycline, amoxicillin, cefuroxime axetil and azithromycin are recommended, while in anaplasmosis the most effective courses of treatment are doxycycline, rifampin and levofloxacin). Consequently, the role of A. phagocytophilum in erythema migrans should be further studied.