Concomitant human granulocytic anaplasmosis and Lyme neuroborreliosis.

Tick-transmitted zoonoses such as human granulocytic anaplasmosis (HGA), Lyme borreliosis and tick-borne encephalitis (TBE) are endemic in several European countries, including Slovenia. Ixodes ricinus, the most prevalent species of hard ticks in Slovenia, is the principal vector for Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and TBE virus [1]. Information on clinically manifested co-infections with tick-transmitted pathogens is incomplete. Findings from the USA indicate that the frequency of simultaneous diseases caused by infection with more than one tick-borne pathogen is low and varies among geographic regions. Reports from the USA involve cases with concurrent erythema migrans (early localised borrelial skin infection) and HGA [2]. Data on co-infections with different tick-borne pathogens in Europe are limited to the reports on co-infections with TBE virus and B. burgdorferi s.l. in patients with acute meningitis [1] and on co-infection with TBE virus and A. phagocytophilum [3]. The other possible combinations in European populations, including infections with A. phagocytophilum and B. burgdorferi s.l., have been indicated mainly but not exclusively by serological findings [3–5]. Residents of Slovenia are often exposed to ticks and thus are at risk of acquiring infection with multiple tick-borne pathogens. Herein we present a patient with acute HGA, established by positive PCR result and seroconversion, in whom borrelial infection was ascertained by the isolation of Borrelia garinii from cerebrospinal fluid (CSF). C A S E P R E S E N T A T I O N