Ehrlichiosis and Anaplasmosis among Transfusion and Transplant Recipients in the United States.

Ehrlichiosis and anaplasmosis are emerging tickborne diseases that can also be transmitted through blood transfusions or organ transplants. Since 2000, ehrlichiosis and anaplasmosis cases in the United States have increased substantially, resulting in potential risk to transplant and transfusion recipients. We reviewed ehrlichiosis and anaplasmosis cases among blood transfusion and solid organ transplant recipients in the United States from peer-reviewed literature and Centers for Disease Control and Prevention investigations. We identified 132 cases during 1997-2020, 12 transfusion-associated cases and 120 cases in transplant recipients; 8 cases were donor-derived, and in 13 cases illness occurred <1 year after transplant. Disease in the remaining 99 cases occurred ≥1 year after transplant, suggesting donor-derived disease was unlikely. Severe illness or death were reported among 15 transfusion and transplant recipients. Clinicians should be alert for these possible infections among transfusion and transplant recipients to prevent severe complications or death by quickly treating them.