TITLE:
Aetiology of Tick-Borne Infections in an Adult Swedish Population—Are Co-Infections with Multiple Agents Common?
AUTHORS:
Marika Nordberg, Pia Forsberg, Johan Berglund, Anneli Bjöersdorff, Jan Ernerudh, Ulf Garpmo, Mats Haglund, Kenneth Nilsson, Ingvar Eliasson
KEYWORDS:
Epidemiology; Tick-Borne Infections; Tick-Borne Encephalitis; Lyme Borreliosis; Human Granulocytic Anaplasmosis
JOURNAL NAME:
Open Journal of Clinical Diagnostics,
Vol.4 No.1,
March
21,
2014
ABSTRACT: 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.