Human granulocytic anaplasmosis (HGA) is a tick-borne, acute illness with increasing incidence [1]. It is caused by Anaplasma phagocytophilum proved to have a tick vector Ixodes ricinus in Europe. HGA is usually a mild or even asymptomatic illness with non-specific influenza-like symptoms, and is associated with variable but suggestive laboratory alterations. When comparing HGA with human ehrlichiosis caused by Ehrlichia chaffeensis, beside differences in geographical distribution, there is a close association with higher hospitalization rate (36% vs. 48.6%), morbidity and life-threatening complications (e.g. adult respiratory distress syndrome, disseminated intravascular coagulopathy, meningoencephalitis, renal failure) and mortality (0.6% vs. 1.9%) in E. chaffeensis cases [1]. A rush, as a clinical presentation, is also more frequently reported in patients with E. chaffeensis. HGA occurs in previously healthy individuals, and the disease severity is associated with the degree of compromised immunity of infected patients. The diagnosis is confirmed retrospectively using specific laboratory tests, which include positive polymerase chain reaction (PCR), identification of A. phagocytophilum in a culture of acute-phase blood, or the detection of specific antibodies to A. phagocytophilum in convalescent-phase serum samples. Doxycycline provides rapid and effective treatment.