[Human granulocytic ehrlichiosis in Norway]

The bacterium that causes human granulocytic ehrlichiosis may be transmitted by ticks.

We describe two patients with human granulocytic ehrlichiosis. During the summer of 1998, both patients were bitten by ticks. Four to 7 days later they developed influenza-like symptoms with fever, headache and myalgia. After 4 and 21 days, respectively, both patients were given doxycycline for suspected bacterial respiratory diseases, and recovered.

Blood samples for human granulocytic ehrlichiosis antibodies showed a fourfold increase in titer in one patient and a remaining high titer in the other. Both patients had a positive polymerase chain reaction with primers specific for the Ehrlichia phagocytophilae genogroup.

The two patients fulfill the human granulocytic ehrlichiosis diagnostic criteria set by Centers for Disease Controls and Prevention, and are the first two human granulocytic ehrlichiosis cases described in Norway.