Prophylactic Use of Sustained-Release Doxycycline Blocks Tick-Transmitted Infection by Anaplasma phagocytophilum in a Murine Model

: A sustained‐release formulation of doxycycline hyclate was tested for its ability to block Anaplasma phagocytophilum infection in mice. Mice treated with sustained‐release doxycycline showed no splenomegaly and their blood samples were negative by PCR on days 7, 14, and 21. Control mice treated with either oral doxycycline or water had significant splenomegaly and were PCR positive at multiple time points. The sustained‐release doxycycline formulation was shown to be efficacious for preventing tick‐transmitted A. phagocytophilum infection in a mouse model.