Clinical distinction between human granulocytic ehrlichiosis and the initial phase of tick-borne encephalitis

Objectives: The aim of our study was to establish clinical and laboratory d ifferences between patients with acute human granulocytic ehrlichiosis (HGE ) and patients with the initial phase of tick-borne encephalitis (TBE). Methods: Clinical features and laboratory results of four patients with acu te HGE (established by the presence of the specific. DNA sequences of the H GE agent in whole blood by polymerase chain reaction and/or by seroconversi on to the HGE agent by indirect immunofluorescence assay) and 12 patients w ith the initial phase of TBE (demonstrated by the presence of serum IgM ant ibodies to TBE virus) were compared. All these patients were uncovered at t he Department of Infectious Diseases, University Medical Centre, Ljubljana, Slovenia, during 1995-1996, in a prospective study on the aetiology of feb rile illnesses occurring within 6 weeks after a tick bite. Results: Findings were similar for the majority of the examined parameters including severity of illness, level and duration of fever, presence of hea dache, leukopenia, thrombocytopenia, and liver - function test abnormalitie s. Statistically significant differences were found only for arthralgia (P= 0.026) and elevated concentration of C-reactive protein (P=0.003); both var iables were found more often in patients with acute HGE. Conclusions: In a patient residing in the central part of Slovenia, who rep orts a tick bite followed by a febrile illness with leukopenia and/or throm bocytopenia, the presence of arthralgias and/or an elevated C-reactive prot ein value directs toward the diagnosis of acute HGE and against the initial phase of TBE. (C) 2000 The British Infection Society.