Chapter 110 – Anaplasma

Anaplasma phagocytophilum is a rickettsial pathogen transmitted by ixodid ticks. A. phagocytophilum colonises myeloid and non-myeloid cells and causes human granulocytic anaplasmosis – an important disease in the United States, Europe and Asia. Research has illustrated how A. phagocytophilum successfully invades and proliferates inside host cells, causing a systemic disease. Here, we address A. phagocytophilum biology and the underlying mechanisms involved in bacterial pathogenesis and disease development. Clinical features, diagnostics and treatment are also discussed, as well as the contribution of the tick vector for microbial transmission.