title: Plasmodium vivax infections in U.S. Army troops: failure of primaquine to prevent relapse in studies from Somalia.
abstract: Different strains of Plasmodium vivax vary in their sensitivity to primaquine, the only drug that prevents relapses. Described are the clinical data and relapse pattern for 75 soldiers treated for vivax malaria since returning from Somalia. Following their initial attack of malaria, 60 of the 75 cases received a standard course of primaquine (15 mg base daily for 14 days). Twenty-six of the 60 soldiers subsequently relapsed for a failure rate of 43%. Eight soldiers had a second relapse following primaquine therapy after both the primary attack and first relapse. Three of these soldiers had received a higher dosage of primaquine (30 mg base daily for 14 days) after their second attack. The apparent ineffectiveness of primaquine therapy in preventing relapses suggests the presence of primaquine-resistant P. vivax strains in Somalia.
authors.affiliation: Division of Preventive Medicine, Walter Reed Army Institute of Research, Washington, District of Columbia, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Smoak
authors.forename: R F
authors.initials: RF
authors.lastname: DeFraites
authors.forename: A J
authors.initials: AJ
authors.lastname: Magill
authors.forename: K C
authors.initials: KC
authors.lastname: Kain
authors.forename: B T
authors.initials: BT
authors.lastname: Wellde
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use*; D004351:Drug Resistance; D006801:Humans; D016780:Malaria, Vivax / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D008297:Male; D015767:Mefloquine / Q000627:therapeutic use; D008889:Military Personnel; D010349:Patient Compliance; D010966:Plasmodium vivax / Q000187:drug effects; D011319:Primaquine / Q000494:pharmacology / Q000627:therapeutic use*; D012008:Recurrence; D012998:Somalia / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014481:United States
chemical_list: D000962:Antimalarials; D011319:Primaquine; D015767:Mefloquine