Babesia microti
Babesia microti
Human babesiosis is a tick-borne infectious disease caused by intraerythrocytic protozoan species of the genus Babesia transmitted by Ixodes. Babesia microti is the most common cause of human babesiosis endemic in USA on the northeastern seabord and the upper midwest. The first confirmed case was a normosplenic individual on Nantucket Island published in 1970. After additional cases the disease became known as Nantucket fever. The incubation period may last from 1 to 9 weeks and clinical features are similar to those of malaria. The severity is variable depending on the immune status of the host, ranging from an asymptomatic infection to a severe life threatening disease. Severe disease generally occurs in patients over the age of 50 years or with splenectomy, malignancy, HIV, or immunosuppressive medication. B. microti infections can also rarely be acquired by transfusion of blood products from asymptomatic donors. In Europe few isolated cases have been reported related to other Babesia species: B. divergens and B. venatorum. Most of European cases are observed in splenectomized patients.
Background
Human babesiosis is a tick-borne infectious disease caused by intraerythrocytic protozoan species of the genus Babesia transmitted by Ixodes. Babesia microti is the most common cause of human babesiosis endemic in USA on the northeastern seabord and the upper midwest. The first confirmed case was a normosplenic individual on Nantucket Island published in 1970. After additional cases the disease became known as Nantucket fever. The incubation period may last from 1 to 9 weeks and clinical features are similar to those of malaria. The severity is variable depending on the immune status of the host, ranging from an asymptomatic infection to a severe life threatening disease. Severe disease generally occurs in patients over the age of 50 years or with splenectomy, malignancy, HIV, or immunosuppressive medication. B. microti infections can also rarely be acquired by transfusion of blood products from asymptomatic donors. In Europe few isolated cases have been reported related to other Babesia species: B. divergens and B. venatorum. Most of European cases are observed in splenectomized patients.