title: Epidemiological and entomological studies of a malaria outbreak among French armed forces deployed at illegal gold mining sites reveal new aspects of the disease's transmission in French Guiana.
abstract: BACKGROUND
  In December 2010, a Plasmodium vivax malaria outbreak occurred among French forces involved in a mission to control illegal gold mining in French Guiana. The findings of epidemiological and entomological investigations conducted after this outbreak are presented here.
  
  
  METHODS
  Data related to malaria cases reported to the French armed forces epidemiological surveillance system were collected during the epidemic period from December 2010 to April 2011. A retrospective cohort study was conducted to identify presumed contamination sites. Anopheles mosquitoes were sampled at the identified sites using Mosquito Magnet and CDC light traps. Specimens were identified morphologically and confirmed using molecular methods (sequencing of ITS2 gene and/or barcoding). Anopheles infections with Plasmodium falciparum and P. vivax were tested by both enzyme-linked immunosorbent assay and real-time PCR.
  
  
  RESULTS
  Seventy-two P. vivax malaria cases were reported (three were mixed P. falciparum/P. vivax infections), leading to a global attack rate of 26.5% (72/272). Lack of compliance with vector control measures and doxycycline chemoprophylaxis was reported by patients. Two illegal gold mining sites located in remote areas in the primary forest were identified as places of contamination. In all, 595 Anopheles females were caught and 528 specimens were formally identified: 305 Anopheles darlingi, 145 Anopheles nuneztovari s.l., 63 Anopheles marajoara and 15 Anopheles triannulatus s.l. Three An. darlingi were infected by P. falciparum (infection rate: 1.1%) and four An. marajoara by P. vivax (infection rate: 6.4%).
  
  
  CONCLUSIONS
  The main drivers of the outbreak were the lack of adherence by military personnel to malaria prevention measures and the high level of malaria transmission at illegal gold mining sites. Anopheles marajoara was clearly implicated in malaria transmission for the first time in French Guiana. The high infection rates observed confirm that illegal gold mining sites must be considered as high level malaria transmission areas in the territory.
  
  
  CONCLUSIONS
  Illegal gold mining activities are challenging the control of malaria in French Guiana. Collaboration with neighbouring countries is necessary to take into account mobile populations such as gold miners. Malaria control strategies in the French armed forces must be adapted to P. vivax malaria and sylvatic Anopheles species.
authors.affiliation: French Armed Forces Center for Epidemiology and Public Health (CESPA), Camp Militaire de Sainte Marthe, BP 40026, 13568, Marseille Cedex 02, France. v.pommierdesanti@gmail.com.|Direction Interarmées du Service de Santé en Guyane, Quartier La Madeleine, BP 6019, 97306, Cayenne Cedex, French Guiana. v.pommierdesanti@gmail.com.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pommier de Santi
authors.affiliation: Medical Entomology Unit, Institut Pasteur de la Guyane, 23 Avenue Pasteur, BP 6010, 97306, Cayenne Cedex, French Guiana. rgirod@pasteur-cayenne.fr.
authors.forename: Romain
authors.initials: R
authors.lastname: Girod
authors.affiliation: Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny sur Orge Cedex, France. mariemura@yahoo.fr.
authors.forename: Marie
authors.initials: M
authors.lastname: Mura
authors.affiliation: French Armed Forces Center for Epidemiology and Public Health (CESPA), Camp Militaire de Sainte Marthe, BP 40026, 13568, Marseille Cedex 02, France. aiss.dia@gmail.com.
authors.forename: Aissata
authors.initials: A
authors.lastname: Dia
authors.affiliation: Direction Interarmées du Service de Santé en Guyane, Quartier La Madeleine, BP 6019, 97306, Cayenne Cedex, French Guiana. sbriolant@wanadoo.fr.|Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny sur Orge Cedex, France. sbriolant@wanadoo.fr.|Laboratory of Parasitology, Institut Pasteur de la Guyane, 23 Avenue Pasteur, BP 6010, 97306, Cayenne Cedex, French Guiana. sbriolant@wanadoo.fr.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Briolant
authors.affiliation: Unit of Infectious and Tropical Diseases, Andrée Rosemon Hospital, Avenue des Flamboyants, Cayenne, French Guiana. felix.djossou@wanadoo.fr.
authors.forename: Félix
authors.initials: F
authors.lastname: Djossou
authors.affiliation: Medical Entomology Unit, Institut Pasteur de la Guyane, 23 Avenue Pasteur, BP 6010, 97306, Cayenne Cedex, French Guiana. idusfour@pasteur-cayenne.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dusfour
authors.affiliation: Antenne médicale de Castres, Quartier Fayolle - 68 avenue J. Desplat, CS 50025, 81108, Castres Cedex, France. alexandre.mendibil@gmail.com.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mendibil
authors.affiliation: Department of Infectious Diseases and Tropical Medicine, Laveran Military Teaching Hospital, 34 Boulevard Laveran, BP 50, 13013, Marseille, France. simon-f@wanadoo.fr.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Simon
authors.affiliation: French Armed Forces Center for Epidemiology and Public Health (CESPA), Camp Militaire de Sainte Marthe, BP 40026, 13568, Marseille Cedex 02, France. xavier.deparis@wanadoo.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Deparis
authors.affiliation: Cire Océan Indien, Institut de Veille Sanitaire, 2 bis, av Georges Brassens, CS 61002, 97743, Saint-Denis Cedex 9, Réunion, France. frederic.pages@ars.sante.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pagès
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D005260:Female; D005616:French Guiana / Q000453:epidemiology; D006046:Gold; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology; D008288:Malaria / Q000453:epidemiology* / Q000635:transmission*; D008297:Male; D008906:Mining; D012189:Retrospective Studies
chemical_list: D006046:Gold