Exposure to Deer Blood May Be a Cause of Human Granulocytic Ehrlichiosis

Human granulocytic ehrlichiosis (HGE) was recently recognized in patients from Wisconsin and Minnesota [1]. The illness is probably transmitted through the bite of infected ticks, since >90% of infected patients have described previous exposure to ticks, and the agent ofHGE has been detected in Ixodes scapularis (dammini) ticks [1, 2]. We describe other possible routes of transmission, as we have recently treated three patients from the upper Midwest who may have contracted HGE by exposure to the blood of infected deer. To determine if deer are potential reservoirs for the agent of HGE, we collected samples from the small pools of blood remaining in the abdominal cavities of 42 eviscerated deer carcasses in November 1994. Ehrlichial DNA was detected by peR in 27 (64%) of the 42 blood samples tested by use of the procedure described by Pancholi et al. [2] or Chen et al. [3]. An acute febrile illness developed in three male patients from the upper Midwest in December 1994, and the diagnosis of HGE was confirmed by either seroconversion or high titers of antibody to Erlichia equi [1] and/or by detection of Ehrlichia phagocytophilagroup specific DNA in blood samples [3]. None of the patients could remember preceding exposure to ticks or an actual tick bite, and none of the patients worked outdoors. Each of the men had butchered>250 deer carcasses during the two preceding weekends and had not worn gloves, masks, or protective gear for their eyes. Each patient had sustained numerous cuts on his fingers and hands from knives or sharp bony fragments, and one of the patients had stabbed himself in the thigh while working. All three men had used an electric saw without an attached vapor suction device, and blood frequently splashed on their clothing during their work. Patients 1 and 2 became ill 10 days and 11 days, respectively, after the first exposure to the dead animals, and a presumptive diagnosis of HGE was made within 5 days of the onset of fever. Both patients were treated with oral doxycycline and recovered quickly. Patient 3 never received treatment with doxycycline, and his diagnosis was confirmed retrospectively 45 days after the onset