Human granulocytic ehrlichiosis: a case series from a medical center in New York State.

Background: Human granulocytic ehrlichiosis (HGE) is a newly described illness with few reports in the literature.

Objective: To describe the clinical and laboratory feature of HGE.

Design: Case series.

Setting: Tertiary care facility in New York State.

Patients: 18 adult patients with HGE.

Measurements: Epidemiologic, clinical, and laboratory features; treatment; and outcome of patients with HGE.

Results: Patients presented with such symptoms as fever (94%) and myalgia or arthralgia (78%). Thirteen patients (71%) recalled being bitten by a tick before onset of symptoms. Leukopenia or thrombocytopenia was seen in 82% of patients, and abnormal liver enzyme levels were seen in 81%. Results of polymerase chain reaction were positive in 9 of 12 patients (75%); morulae were seen in 3 of 12 patients (25%); and the agent that causes HGE was cultured from 2 patients. All but one patient (94%) developed antibodies to Ehrlichia equi. Five patients (28%) were briefly hospitalized, and none died. All patients were successfully treated with doxycycline.

Conclusions: The illness associated with HGE in these patients from the northeastern United States was more mild than that originally described in reports of HGE in the midwestern United States.