Author(s)

Marika Nordberg, Pia Forsberg, Johan Berglund, Anneli Bjöersdorff, Jan Ernerudh, Ulf Garpmo, Mats Haglund, Kenneth Nilsson, Ingvar Eliasson

Blekinge Institute of Technology, School of Health Science, Karlskrona, Sweden.
Clinical Immunology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Link?ping University, Department of Clinical Immunology and Transfusion Medicine, County Council of ?sterg?tland, Link?ping, Sweden.
Department of Clinical Microbiology, Kalmar County Hospital, Kalmar, Sweden.
Department of Infectious Diseases, County Council of ?sterg?tland, Link?ping, Sweden.
Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden.
Department of Laboratory Medicine, Norra ?lvsborg County Hospital, Trollh?ttan, Sweden.
Djursjukhusgruppen, Danderyd, Sweden.
Infectious Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Link?ping University, Link?ping, Sweden.
Unit of Clinical Microbiology/Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.

In Scandinavia, tick-borne infections affecting humans include Lyme borreliosis (LB), tick-borne encephalitis (TBE) and human granulocytic anaplasmosis (HGA). Each of these infections can present with unspecific symptoms. In this prospective clinical study, we recruited patients based on two independent inclusion criteria; 1) patients with unspecific symptoms, i.e. fever (≥38.0℃) or a history of feverishness and/or any combination of headache, myalgia or arthralgia and 2) patients with erythema migrans (EM), following an observed tick bite or tick exposure within one month prior to onset of symptoms. A total of 206 patients fulfilled the study. Among these, we could identify 186 cases of LB (174 with EM), 18 confirmed and two probable cases of HGA and two cases of TBE. Thirteen of the HGA cases presented without fever. Furthermore, 22 of the EM patients had a sub-clinical co-infection with Anaplasma phagocytophilum, based on serology. Both TBE cases had co-infections, one with Borrelia burgdorferi and one with Anaplasma phagocytophilum. We conclude that it is important to consider several causative agents and possible co-infections in the clinical management of infectious diseases where ticks may be suspected as vectors.

Epidemiology; Tick-Borne Infections; Tick-Borne Encephalitis; Lyme Borreliosis; Human Granulocytic Anaplasmosis

Nordberg, M. , Forsberg, P. , Berglund, J. , Bjöersdorff, A. , Ernerudh, J. , Garpmo, U. , Haglund, M. , Nilsson, K. and Eliasson, I. (2014) Aetiology of Tick-Borne Infections in an Adult Swedish Population—Are Co-Infections with Multiple Agents Common?. Open Journal of Clinical Diagnostics, 4, 31-40. doi: 10.4236/ojcd.2014.41007.