HUMAN EXPOSURE TO A GRANULOCYTIC EHRLICHIA AND OTHER TICK-BORNE AGENTS IN CONNECTICUT

Indirect fluorescent-antibody (IFA) staining methods with Ehrlichia eq ui (MRK or BDS strains) and Western blot analyses containing a human g ranulocytic ehrlichiosis (HGE) agent (NCH-1 strain) were used to confi rm probable human cases of infection in Connecticut during 1995 and 19 96. Also included were other tests for Ehrlichia chaffeensis, the agen t of human monocytic ehrlichiosis (HME), Babesia microti, and Borrelia burgdorferi. Thirty-three (8.8%) of 375 patients who had fever accomp anied by marked leukopenia or thrombocytopenia were serologically conf irmed as having HGE. Western blot analyses of a subset of positive ser a confirmed the results of the IFA staining methods for 15 (78.9%) of 19 seropositive specimens obtained from different persons. There was f requent detection of antibodies to a 44-kDa protein of the HGE agent. Serologic testing also revealed possible cases of Lyme borreliosis (n = 142), babesiosis (n = 41), and HME (n = 21). Forty-seven (26.1%) of 180 patients had antibodies to two or more tick-borne agents. Therefor e, when one of these diseases is clinically suspected or diagnosed, cl inicians should consider the possibility of other current or past tick -borne infections.