Microbiology
Anaplasma phagocytophilum, Anaplasma ovis, A. marginale, Anaplasma capra (In China (PubMed)), A. phagocytophilia (was Ehrlichia phagocytophilia). In the family of Ehrlichia.
Diagnose with serology (acute and convalescent) AND PCR both (PubMed).
Epidemiologic Risks
A. phagocytophilia from black-legged tick bites (Ixodes scapularis and Ixodes pacificus) in Eastern and Western US, also parks in Germany (and probably elsewhere) (PubMed). In the US, Minnesota, Wisconsin, and Rhode Island have the highest reported cases.
Tick bites in Eastern and Western US, also parks in Germany (and probably elsewhere) (PubMed).
The actual incidence in the Midwest of the US and Canada is likely under-reported.
In Europe, it is spread by Ixodes ricinus and a mild, rare disease. I wonder if it has evolved into a different organism (Pubmed).
Rarely acquired from transfusion (PubMed).
Like many infections, it's range is expanding due to climate changes. It is increasing in Maine, in part due to more testing and in part due to the expansion of the ticks range (Pubmed).
Syndromes
A. phagocytophilia causes human granulocytic anaplasmosis ehrlicheosis (HGA). Fevers, myalgias, transaminitis, low WBC.A rash is rare.
A. capra can have a rash and/or eschar. A rash is rare.
A. marginale infects the erythrocytes of cattle.
Treatment
A. marginale, not a human pathogen. Yet. Someday, some poor cowboy will come down with this.
A. phagocytophilia: doxycycline or tetracycline. Quinolones may work but haven't been tested.
Notes
In HGA 20 - 80% of patients have Anaplasma morulae in peripheral blood neutrophils, rare in HME.
Last update: 01/30/20