title: Persistence of humoral response against sporozoite and blood-stage malaria antigens 7 years after a brief exposure to Plasmodium vivax.
abstract: The persistence of malarial antibodies was evaluated in subjects living in a rural community (in Minas Gerais State, Brazil) briefly exposed to a Plasmodium vivax malaria outbreak outside of the area in which malaria was endemic. Transmission was interrupted by treatment of all patients and their relatives and/or neighbors, although the latter had neither symptoms nor blood parasites. Antibodies to P. vivax antigens (recombinant proteins from sporozoites [rPvCS] and from blood stages [rPv200]) were measured in parallel by ELISA with sera collected at two time points after transmission. Anti-rPvCS IgG antibodies were positive in approximately 40% and 20% of the subjects 8 months and 7 years after exposure, respectively. Anti-rPv200 IgG was first detected in 61% of the subjects who had had malarial symptoms and remained positive in 47% after 7 years. Among the prophylactically treated group, anti-rPv200 IgG was detected in only 28% after 8 months. The levels of both antibodies decreased with time in all positive subjects.
authors.affiliation: Departamento de Parasitologia, Universidade Federal de Minas Gerais and Centro de Pesquisas René Rachou/FIOCRUZ, Belo Horizonte, Brazil.
authors.forename: E M
authors.initials: EM
authors.lastname: Braga
authors.forename: C J
authors.initials: CJ
authors.lastname: Fontes
authors.forename: A U
authors.initials: AU
authors.lastname: Krettli
mesh_terms: D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis* / Q000097:blood / Q000276:immunology*; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D004196:Disease Outbreaks; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D016780:Malaria, Vivax / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D010966:Plasmodium vivax / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016036:Seroepidemiologic Studies; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D011994:Recombinant Proteins