Are other tick-borne infections overlooked in patients investigated for Lyme neuroborreliosis? A large retrospective study from South-eastern Sweden

In Europe, the hard tick Ixodes ricinus is considered most important vector of human zoonotic diseases. Human pathogenic agents spread by I. in Sweden include Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, Rickettsia helvetica, recently described Neoehrlichia mikurensis, miyamotoi, tick-borne encephalitis virus (TBEV), and Babesia spp. (Babesia microti, venatorum divergens). Since these pathogens share same vector, co-infections with more than one pathogen may occur thus complicate diagnosis clinical management patient due to possibly altered symptomatology. s.l., TBEV B. miyamotoi are well-known cause infections central nervous system (CNS), whereas abilities other invade CNS largely unknown. The aim this study was investigate presence impact s.l. cerebrospinal fluid (CSF) serum samples patients who were under investigation for Lyme neuroborreliosis (LNB) a tick-endemic region South-eastern Sweden. CSF from 600 patients, recruited Regions Östergötland County, Jönköping County Kalmar investigated LNB during period 2009–2013, retrospectively collected analysis. analysed real-time PCR nucleic acid A. spp., N. Serological analyses conducted all regarding mononuclear pleocytosis, antibodies spotted fever group (SFG) rickettsiae, microti performed. medical charts pleocytosis positive findings reviewed. Of 55 (9%) presented 13 (2%) whom had Borrelia-specific CSF. One PCR-positive another serum. No detected samples. Four four five SFG six TBEV. patient, both laboratory signs suggestive current infection. Nine pathogen, although none assessed as co-infection. We can conclude that uncommon being suspected Sweden, an area endemic borreliosis TBE.