title: Entomologic and serologic evidence of zoonotic transmission of Babesia microti, eastern Switzerland.
abstract: We evaluated human risk for infection with Babesia microti at a site in eastern Switzerland where several B. microti-infected nymphal Ixodes ricinus ticks had been found. DNA from pooled nymphal ticks amplified by polymerase chain reaction was highly homologous to published B. microti sequences. More ticks carried babesial infection in the lower portion of the rectangular 0.7-ha grid than in the upper (11% vs. 0.8%). In addition, we measured seroprevalence of immunoglobulin (Ig) G antibodies against B. microti antigen in nearby residents. Serum from 1.5% of the 396 human residents of the region reacted to B. microti antigen (>1:64), as determined by indirect immunofluorescence assay (IgG). These observations constitute the first report demonstrating B. microti in a human-biting vector, associated with evidence of human exposure to this agent in a European site.
authors.affiliation: Harvard School of Public Health, Boston, Massachusetts, USA.
authors.forename: Ivo M
authors.initials: IM
authors.lastname: Foppa
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Krause
authors.forename: Andrew
authors.initials: A
authors.lastname: Spielman
authors.forename: Heidi
authors.initials: H
authors.lastname: Goethert
authors.forename: Lise
authors.initials: L
authors.lastname: Gern
authors.forename: Brigit
authors.initials: B
authors.lastname: Brand
authors.forename: Sam R
authors.initials: SR
authors.lastname: Telford
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000302:isolation & purification; D000953:Antigens, Protozoan / Q000302:isolation & purification; D001179:Arthropod Vectors / Q000276:immunology / Q000469:parasitology*; D001403:Babesia / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D001404:Babesiosis / Q000276:immunology / Q000469:parasitology*; D016054:DNA, Protozoan / Q000302:isolation & purification; D006801:Humans; D018884:Ixodes / Q000276:immunology / Q000469:parasitology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D012698:Serologic Tests; D013045:Species Specificity; D013557:Switzerland
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016054:DNA, Protozoan