title: Efficacy in the treatment of malaria by Plasmodium vivax in Oiapoque, Brazil, on the border with French Guiana: the importance of control over external factors.
abstract: BACKGROUND
  Plasmodium vivax malaria is an important public health issue in the Amazon region, and it accounts for approximately 84 % of cases of the disease. Migration across the border between Brazil and French Guiana contributes to the maintenance of the disease. The aim of this study was to evaluate the therapeutic and parasitological responses of patients with P. vivax malaria treated with chloroquine and primaquine in the socio-environmental context of cross-border interactions between Brazil and French Guiana. The factors controlled were diagnostic agreement, adherence, adjustment of primaquine doses for patient weight, and quality of the drugs used.
  
  
  METHODS
  A prospective study was conducted in 2011 with 103 individuals aged 10-60 years with a positive diagnosis of P. vivax treated with chloroquine (10 mg base/kg on the first day, followed by 7.5 mg/kg on the second and third days) and primaquine for 7 days, who were followed for 28 days. The primaquine doses were adjusted for the patients' weight. A number of factors were determined: epidemiological characteristics, origin of patients, signs and symptoms, initial parasitaemia and parasitaemia clearance time, blood concentrations of chloroquine and primaquine, quality of anti-malarial drugs and diagnostic agreement.
  
  
  RESULTS
  Ninety-five patients were followed for 28 days. There was a 100 % agreement in microscopic diagnosis between field laboratory and reference centre. The adhesion to the treatment was 100 %. Of these patients, 32.6 % received a weight-adjusted dose of primaquine. The chloroquine and primaquine tablets were consistent with the optimal quality limits for human consumption. The investigated patients achieved optimal blood exposure to anti-malarial drugs. The parasitological and therapeutic response was adequate in 99.0 % of cases.
  
  
  CONCLUSIONS
  In the municipality of Oiapoque, the therapeutic regime used for the treatment of P. vivax malaria using chloroquine combined with primaquine remains effective, when external factors are controlled, such as the quality of anti-malarial drugs, the adhesion to the treatment prescribed, the correct diagnostic and the adjustment of primaquine dose for patient body weight.
authors.affiliation: Central Laboratory of Public Health of Amapá (Laboratório Central de Saúde Pública do Amapá - LACEN-AP), Macapá, Amapá, Brazil. margarete.m.gomes@gmail.com.|Federal University of Pará (Universidade Federal do Pará - UFPA), Belém, Pará, Brazil. margarete.m.gomes@gmail.com.
authors.forename: Margarete do Socorro M
authors.initials: Mdo S
authors.lastname: Gomes
authors.affiliation: Federal University of Pará (Universidade Federal do Pará - UFPA), Belém, Pará, Brazil. jvieira@ufpa.br.
authors.forename: José Luiz F
authors.initials: JL
authors.lastname: Vieira
authors.affiliation: 'Evandro Chagas' Institute (Instituto Evandro Chagas), Belém, Pará, Brazil. ricardomachado@iec.pa.gov.br.
authors.forename: Ricardo L D
authors.initials: RL
authors.lastname: Machado
authors.affiliation: Université des Antilles et de la Guyane, Cayenne, French Guiana. mathieu.nacher@ch-cayenne.fr.|Centre d'Investigation Clinique - Epidémiologie Clinique Antilles-Guyane (CIC-EC INSERM CIE 802), Cayenne General Hospital, Cayenne, French Guiana. mathieu.nacher@ch-cayenne.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Nacher
authors.affiliation: Université des Antilles et de la Guyane, Cayenne, French Guiana. aurelia.stefani@gmail.com.|Institut Pasteur de la Guyane, Cayenne, French Guiana. aurelia.stefani@gmail.com.
authors.forename: Aurélia
authors.initials: A
authors.lastname: Stefani
authors.affiliation: Institut Pasteur de la Guyane, Cayenne, French Guiana. lisemusset@gmail.com.
authors.forename: Lise
authors.initials: L
authors.lastname: Musset
authors.affiliation: Institut Pasteur de la Guyane, Cayenne, French Guiana. elegrand@pasteur-cayenne.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Legrand
authors.affiliation: Central Laboratory of Public Health of Amapá (Laboratório Central de Saúde Pública do Amapá - LACEN-AP), Macapá, Amapá, Brazil. ra-menezes@hotmail.com.
authors.forename: Rubens A O
authors.initials: RA
authors.lastname: Menezes
authors.affiliation: Central Laboratory of Public Health of Amapá (Laboratório Central de Saúde Pública do Amapá - LACEN-AP), Macapá, Amapá, Brazil. aldo.proietti@unifap.br.|Federal University of Amapá (Universidade Federal do Amapá - UNIFAP), Macapá, Amapá, Brazil. aldo.proietti@unifap.br.
authors.forename: Aldo A P
authors.initials: AA
authors.lastname: Júnior
authors.affiliation: Federal University of Amapá (Universidade Federal do Amapá - UNIFAP), Macapá, Amapá, Brazil. anapsosa@hotmail.com.
authors.forename: Ana P M
authors.initials: AP
authors.lastname: Sousa
authors.affiliation: Amapá State Health Department (Secretaria de Estado da Saúde do Amapá - SESA), Macapá, Amapá, Brazil. vs.pc@hotmail.com.
authors.forename: Vanja S C D'Almeida
authors.initials: VS
authors.lastname: Couto
authors.affiliation: Federal University of Pará (Universidade Federal do Pará - UFPA), Belém, Pará, Brazil. alvaro.couto6@hotmail.com.
authors.forename: Álvaro A R D'Almeida
authors.initials: ÁA
authors.lastname: Couto
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000008:administration & dosage*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002738:Chloroquine / Q000008:administration & dosage; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D005616:French Guiana; D063426:Human Migration; D006801:Humans; D016780:Malaria, Vivax / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D011319:Primaquine / Q000008:administration & dosage; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000962:Antimalarials; D002738:Chloroquine; D011319:Primaquine