Granulocytic anaplasmosis is an emerging tick-borne disease occurring in humans and animals. It is evoked by obligatory intracellular small Gram-negative bacteria of the species Anaplasma phagocytophilum. They propagate inside peripheral blood granulocytes, mainly neutrophils, inhibiting apoptosis of these cells and forming in vacuoles microcolonies called morulae. In Europe, ticks Ixodes ricinus are vectors of the disease, while deer are probably reservoir hosts of pathogenic bacteria.

Human granulocytic anaplasmosis is an acute disease manifested by fever. Clinical symptoms are non-specific, which hinders the diagnosis. The occupational risk groups are forestry workers, farmers and hunters. On the territory of Lublin region between 17.7-21.0% of forestry workers show the presence of antibodies towards Anaplasma phagocytophilum, and a significant correlation exists between infection rates in ticks and forestry workers. Urban dwellers visiting forest areas for recreational purposes are also under risk of infection. The broad range of exposed persons highlights the granulocytic anaplasmosis as an important problem of public health.

In diagnosis of granulocytic anaplasmosis the most impor- tant is immunofluorescence test for detection of specific an- tibodies in blood serum sample. Health education is of basic significance in prevention of the disease.