Confusing variety of symptoms: Lyme carditis coinciding with Puumala hantavirus infection

The temporal coincidence of a tick- and rodent-associated disease led to a confusing variety of symptoms, which posed diagnostic challenges. A 51-year old otherwise healthy patient developed high fever, pronounced cephalgia and acute renal failure a few days after the onset of erythema migrans. Bradycardia and other cardiac symptoms with left ventricular failure occurred in the course of the disease, which were interpreted as Lyme carditis. Serological evidence of both early Lyme disease and hantavirus infection was found. For hantaviruses, the additional detection of viral RNA confirmed the viremia. Discharge from inpatient treatment was only possible after 3 weeks of therapy. The convalescence period lasted approx. 6 months.