Human ehrlichiosis is a serious disease that can be fatal if not treated appropriately. We examined patients with a clinical presentation consistent with the syndrome of
ehrlichiosis and a positive blood polymerase chain reaction (PCR) test for all known Ehrlichia species or Anaplasma phagocytophilum admitted to Barnes-Jewish Hospital in St. Louis, MO, from 1996 to 2006. Patients who had
doxycycline initiated within the first 24 hours of admission to the hospital were compared with patients who did not have empiric
doxycycline therapy. A total of 46 patients had a positive blood PCR test for Ehrlichia or Anaplasma phagocytophilum, and 28 (60.9%) had a delay in
doxycycline therapy. At presentation, patients with a delay in
therapy were more likely to present with an abnormal lung exam and altered mental status. None of the patients experiencing a delay in
doxycycline treatment had the diagnosis of
ehrlichiosis documented at the time of hospital admission, compared with 13 (72.2%) of the patients who were treated empirically (p < 0.001). Patients not started on
doxycycline at hospital admission had a significantly increased rate of transfer to the intensive care unit (39.3% vs. 0%; p < 0.001) and requirement for
mechanical ventilation (28.6% vs. 0%; p < 0.001). Patients with a
treatment delay also had a longer
hospital stay (12.3 +/- 11 d vs. 3.9 +/- 1.9 d, respectively; p < 0.001) and a longer length of illness (20.9 +/- 14.2 d vs. 8.9 +/- 2.7 d, respectively; p = 0.001). These data suggest that clinicians living in an area where Ehrlichia is endemic should have a high suspicion for
ehrlichiosis, and a low threshold for instituting empiric
antibiotic therapy with
doxycycline.