title: Hyperendemic malaria transmission in areas of occupation-related travel in the Peruvian Amazon.
abstract: BACKGROUND
  Plasmodium vivax and Plasmodium falciparum cause a significant illness burden in Peru. Anopheline indices for populated communities in the peri-Iquitos region of Loreto have been reported to be remarkably low, with entomological inoculation rates (EIR) estimated at one to 30 infective bites per year based on a few studies in close proximity to the urban centre of Iquitos and surrounding deforested areas. Local reports suggest that a large number of the reported cases are contracted outside of populated communities in undeveloped riverine areas frequented by loggers and fishermen.
  
  
  METHODS
  To better understand vectorial capacity in suspected high malaria transmission zones in a rural district near Iquitos, Peru, mosquito collections were conducted at different points in the seasonality of malaria transmission in 21 sites frequented by occupational labourers. Prevalence of Plasmodium spp in vectors was determined by circumsporozoite protein ELISA on individual mosquitoes. Slide surveillance was performed for humans encountered in the zone.
  
  
  RESULTS
  In total, of 8,365 adult female mosquitoes examined, 98.5% were identified as Anopheles darlingi and 117 (1.4%) tested positive for sporozoites (P. falciparum, P. vivax VK210 or P. vivax VK247). Measured human biting rates at these sites ranged from 0.102 to 41.13 bites per person per hour, with EIR values as high as 5.3 infective bites per person per night. Six percent of the 284 blood films were positive for P. vivax or P. falciparum; however, 88% of the individuals found to be positive were asymptomatic at the time of sampling.
  
  
  CONCLUSIONS
  The results of this study provide key missing indices of prominent spatial and temporal heterogeneity of vectorial capacity in the Amazon Basin of Peru. The identification of a target human subpopulation as a principal reservoir and dispersion source of Plasmodium species has important implications for vaccine development and the delivery of effective targeted malaria control strategies.
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Room E5545, Baltimore, Maryland 21205, USA.
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Parker
authors.forename: Maribel
authors.initials: M
authors.lastname: Paredes Olortegui
authors.forename: Pablo
authors.initials: P
authors.lastname: Peñataro Yori
authors.forename: Karin
authors.initials: K
authors.lastname: Escobedo
authors.forename: David
authors.initials: D
authors.lastname: Florin
authors.forename: Silvia
authors.initials: S
authors.lastname: Rengifo Pinedo
authors.forename: Roldan
authors.initials: R
authors.lastname: Cardenas Greffa
authors.forename: Luis
authors.initials: L
authors.lastname: Capcha Vega
authors.forename: Hugo
authors.initials: H
authors.lastname: Rodriguez Ferrucci
authors.forename: William K
authors.initials: WK
authors.lastname: Pan
authors.forename: Cesar
authors.initials: C
authors.lastname: Banda Chavez
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Vinetz
authors.forename: Margaret
authors.initials: M
authors.lastname: Kosek
mesh_terms: D000818:Animals; D009033:Culicidae / Q000145:classification / Q000469:parasitology*; D019353:Endemic Diseases; D005260:Female; D005843:Geography; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000635:transmission*; D016780:Malaria, Vivax / Q000453:epidemiology / Q000635:transmission*; D016273:Occupational Exposure; D010568:Peru / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000302:isolation & purification; D010966:Plasmodium vivax / Q000302:isolation & purification; D014195:Travel