title: The single water-surface sweep estimation method accurately estimates very low (n = 4) to low-moderate (n = 25-100) and high (n > 100) Aedes aegypti (Diptera: Culicidae) pupae numbers in large water containers up to 13 times faster than the exhaustive sweep and total count method and without any sediment contamination.
abstract: OBJECTIVE
  To confirm that a single water-surface sweep-net collection coupled with three calibration factors (2.6, 3.0 and 3.5 for 1/3, 2/3 and 3/3 water levels, respectively) (WSCF) could accurately estimate very low to high Aedes aegypti pupae numbers in water containers more rapidly than the exhaustive 5-sweep and total count (ESTC) method recommended by WHO.
  
  
  METHODS
  Both methods were compared in semi-field trials using low (n = 25) to moderate (n = 50-100) pupae numbers in a 250-l drum at 1/3, 2/3 and 3/3 water levels, and by their mean-time determinations using 200 pupae in three 220- to 1024-l water containers at these water levels. Accuracy was further assessed using 69.1% (393/569) of the field-based drums and tanks which contained <100 pupae.
  
  
  RESULTS
  The WSCF method accurately estimated total populations in the semi-field trials up to 13.0 times faster than the ESTC method (all P < 0.001); no significant differences (all P-values ≥ 0.05) were obtained between the methods for very low (n = 4) to low-moderate (n = 25-100) and high (n > 100) pupae numbers/container and without sediment disturbance.
  
  
  CONCLUSIONS
  The simple WSCF method sensitively, accurately and robustly estimated total pupae numbers in their principal breeding sites worldwide, containers with >20 l water volumes, significantly (2.7- to 13.0-fold: all P-values <0.001) faster than the ESTC method for very low to high pupae numbers/container without contaminating the clean water by sediment disturbance which is generated using the WHO-recommended ESTC method. The WSCF method seems ideal for global community-based surveillance and control programmes.
authors.affiliation: Grupo de Investigaciones en Enfermedades Tropicales, Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia.
authors.forename: C M
authors.initials: CM
authors.lastname: Romero-Vivas
authors.forename: H
authors.initials: H
authors.lastname: Llinás
authors.forename: A K
authors.initials: AK
authors.lastname: Falconar
mesh_terms: D000330:Aedes; D000818:Animals; D003715:Dengue / Q000517:prevention & control*; D004784:Environmental Monitoring / Q000379:methods*; D006794:Household Articles; D007303:Insect Vectors; D011156:Population Density; D011679:Pupa; D014867:Water / Q000469:parasitology*
chemical_list: D014867:Water
keywords: Aedes aegypti; balayage de la surface de l'eau; barrido sobre superficie de agua; calibration factor; chiffres totaux; conteo total; cálculo; estimation; facteur d’étalonnage; factor de calibración; nymphes; pupae; pupas; total counts; water-surface sweeping