IMMUNOSEROLOGIC EVIDENCE OF HUMAN GRANULOCYTIC EHRLICHIOSIS IN DANISHPATIENTS WITH LYME NEUROBORRELIOSIS

Human Granulocytic Ehrlichiosis (HGE) is a recently described human il lness in the US which manifests as fever, myalgia and headache combine d with pancytopenia and elevated concentrations of hepatic transaminas es. Genetic analyses indicate that the agent of HGE appears to be an E hrlichia species that is closely related to E. equi and E. phagocytoph ila. Ixodes dammini and I. scapularis were identified as potential vec tors of HGE. bodes ticks are also the,vector of Borrelia burgdorferi, the agent of Lyme borreliosis. The presence of antibodies against Ehrl ichia in 132 sera from Danish patients with definite Lyme neuroborreli osis were examined in order to provide immunoserologic evidence of thi s infection in Denmark. Patients with Lyme neuroborreliosis were chose n as a test cohort, as these patients had been infested by a tick suff icient for transmission of B. burgdorferi. All had cerebrospinal fluid lymphocytic pleocytosis. As controls, serum samples from 50 healthy D anish blood donors were included. Of the 132 patients with Lyme neurob orreliosis, 5 (3.8%) reacted with the E. equi antigen substrate at tit res 1:128. None of the blood donors were found seropositive for E. equ i. At least 2 of the patients found seropositive for HGE constituted p robable cases of HGE with E. equi antibody titres of at least 80 combi ned with fever, headache and myalgias. However, in no cases were we ab le to detect the presence of the HGE agent in the serum by PCR. We con clude that human exposure to granulocytic Ehrlichiae species may also occur in Europe, although further studies will be necessary to documen t active infection with these potential pathogens.