title: Experimental transfusion-induced Babesia microti infection: dynamics of parasitemia and immune responses in a rhesus macaque model.
abstract: Babesiosis is an emerging tick-borne infection in humans. The increasing numbers of reported cases of transfusion-associated babesiosis (TAB), primarily caused by Babesia microti, represents a concern for the safety of the US blood supply.
  
  
  
  This study investigated kinetics of parasitemia and innate immune responses and dynamics of antibody responses during B. microti infection in rhesus macaques (RMs) using blood smears, quantitative polymerase chain reaction (qPCR), flow cytometry, and indirect fluorescent antibody testing. A total of six monkeys were transfused with either hamster or monkey-passaged B. microti-infected red blood cells (two and four monkeys, respectively) simulating TAB.
  
  
  
  The prepatent period in monkeys inoculated with hamster-passaged B. microti was 35 days compared with 4 days in monkeys transfused with monkey-passaged B. microti; the latter monkeys also had markedly higher parasitemia levels. The duration of the window period from the first detected parasitemia by qPCR analysis to the first detected antibody response ranged from 10 to 17 days. Antibody responses fluctuated during the course of the infection. Innate responses assessed by the frequencies of monocytes and activated B cells correlated with the kinetics and magnitude of parasitemia. On Day 14, additional activation peaks were noted for CD14+CD16+ and CD14-CD16+ monocytes and for CD11c+ myeloid dendritic cells, but only in animals transfused with monkey-passaged B. microti. Parasitemia persisted in these immunocompetent animals, similar to human infection.
  
  
  
  The results suggest that transfusion-associated transmission of B. microti leads to rapid onset of parasitemia (Day 4) in RMs, detectable antibody response 14 days later, and persistent parasitemia.
authors.affiliation: Division of Pathology, Yerkes National Primate Research Center, Atlanta, Georgia.|Department of Pathology and Laboratory Medicine, Emory University School of Medicine.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Gumber
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Fernanda S
authors.initials: FS
authors.lastname: Nascimento
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Rogers
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Henry S
authors.initials: HS
authors.lastname: Bishop
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Hilda N
authors.initials: HN
authors.lastname: Rivera
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Maniphet V
authors.initials: MV
authors.lastname: Xayavong
authors.affiliation: Abbott Diagnostics, Abbott Laboratories, Abbott Park, Illinois.
authors.forename: Sushil G
authors.initials: SG
authors.lastname: Devare
authors.affiliation: Abbott Diagnostics, Abbott Laboratories, Abbott Park, Illinois.
authors.forename: Gerald
authors.initials: G
authors.lastname: Schochetman
authors.affiliation: Division of Microbiology and Immunology, Yerkes National Primate Research Center.
authors.forename: Praveen K
authors.initials: PK
authors.lastname: Amancha
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Qvarnstrom
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control & Prevention, Atlanta, Georgia.
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Wilkins
authors.affiliation: Division of Microbiology and Immunology, Yerkes National Primate Research Center.|Department of Pathology and Laboratory Medicine, Emory University School of Medicine.
authors.forename: François
authors.initials: F
authors.lastname: Villinger
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001404:Babesiosis / Q000175:diagnosis / Q000276:immunology / Q000635:transmission*; D006224:Cricetinae; D004195:Disease Models, Animal; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D000882:Haplorhini; D007700:Kinetics; D008253:Macaca mulatta / Q000097:blood / Q000276:immunology* / Q000469:parasitology; D018512:Parasitemia / Q000097:blood / Q000175:diagnosis / Q000635:transmission; D016133:Polymerase Chain Reaction; D065227:Transfusion Reaction
chemical_list: D000913:Antibodies, Protozoan