A. phagocytophilum is transmitted to humans by Ixodes ticks. These ticks are found in the US, Europe, and Asia. In the US, I. scapularis is the tick vector in the East and Midwest states, and I. pacificus in the Pacific Northwest. In Europe, the I. ricinus is the main tick vector, and I. persulcatus is the currently known tick vector in Asia. The major mammalian reservoir for A. phagocytophilum in the eastern United States is the white-footed mouse, Peromyscus leucopus. Although white-tailed deer and other small mammals harbor A. phagocytophilum, evidence suggests that they are not a reservoir for the strains that cause<unk> . A tick that has a blood meal from an infected reservoir becomes infected themselves. If an infected tick then latches onto a human the disease is then transmitted to the human host and A. phagocytophilum symptoms can arise. Anaplasma phagocytophilum shares its tick vector with other human pathogens, and about 10% of patients with<unk>  show serologic evidence of coinfection with Lyme disease, babesiosis, or tick-borne meningoencephalitis. While it is rare, it is possible for<unk>  to be transmitted human-to-human via a blood transfusion, in which case it is called Transfusion-Transmitted<unk>  (TTA). Major surface proteins Many MSPs are found in Anaplasma and those which interact with Anaplasma can mainly be found in A. marginale and A. phagocytophilum. There are many different phenotypic traits that are associated with MSPs, because each MSP can only infect certain animals in certain conditions. A. phagocytophilum infects the most vast array of living things, including humans, and all around the world. A. marginale evolved to be more specific in infecting animals, such as deer and cattle in the subtropics and tropics. The main difference between these two MSPs is that the host cell for A. phagocytophilum is the granulocyte, while the host cell for A. marginale is erythrocytes. It is likely that these MSPs coevolved, because they had previously interacted via tick-pathogen interaction. Anaplasma MSPs can not only cooperate with vertebrates, but also invertebrates, which make these phenotypes evolve faster than others, because they have a lot of selective forces acting on them.
Human granulocytic anaplasmosis
AIDS-related lymphoma
Infectious mononucleosis
Burkitt lymphoma
Toxoplasmosis
Human monocytotropic ehrlichiosis
Cytomegalic inclusion body disease
African histoplasmosis