title: Regional differences in the response of Plasmodium vivax malaria to primaquine as anti-relapse therapy.
abstract: We used logistic regression to assess effectiveness of primaquine as Plasmodium vivax anti-relapse therapy using data extracted from studies of P. vivax relapses in Brazil, India, and Thailand. The risk of relapse in Thailand was 10 times that in India and twice that in Brazil. In comparison with no primaquine treatment, the risk of relapse decreased by approximately 80% for a total adult primaquine regimen of 210 mg and by > or =95% for regimens of 315 mg and 420 mg. In addition, we used logistic regression to estimate the risk of P. vivax relapse according to weight-based primaquine dose using data from case studies. There was a three-fold increase in the likelihood of successful treatment of each additional milligram of primaquine per kilogram of body weight. Tailoring primaquine therapy to a region requires consideration of factors including body weight, natural relapse rates, and local response to primaquine.
authors.affiliation: Department of Medicine and Centre for Clinical Research Excellence in Infectious Diseases, The University of Melbourne, The Royal Melbourne Hospital, Parkville, Victoria, Australia. jane@burnet.edu.au
authors.forename: Jane L
authors.initials: JL
authors.lastname: Goller
authors.forename: Damien
authors.initials: D
authors.lastname: Jolley
authors.forename: Pascal
authors.initials: P
authors.lastname: Ringwald
authors.forename: Beverley-Ann
authors.initials: BA
authors.lastname: Biggs
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D001835:Body Weight; D001938:Brazil / Q000453:epidemiology; D006801:Humans; D007194:India / Q000453:epidemiology; D016780:Malaria, Vivax / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control*; D010966:Plasmodium vivax / Q000254:growth & development*; D011319:Primaquine / Q000627:therapeutic use*; D012044:Regression Analysis; D055502:Secondary Prevention; D013785:Thailand / Q000453:epidemiology
chemical_list: D000962:Antimalarials; D011319:Primaquine