title: Surveillance of Aedes aegypti: comparison of house index with four alternative traps.
abstract: BACKGROUND
  The mosquito Aedes aegypti, vector of dengue, chikungunya and yellow fever viruses, is an important target of vector control programs in tropical countries. Most mosquito surveillance programs are still based on the traditional household larval surveys, despite the availability of new trapping devices. We report the results of a multicentric entomological survey using four types of traps, besides the larval survey, to compare the entomological indices generated by these different surveillance tools in terms of their sensitivity to detect mosquito density variation.
  
  
  METHODS
  The study was conducted in five mid-sized cities, representing variations of tropical climate regimens. Surveillance schemes using traps for adults (BG-Sentinel, Adultrap and MosquiTRAP) or eggs (ovitraps) were applied monthly to three 1 km(2) areas per city. Simultaneously, larval surveys were performed. Trap positivity and density indices in each area were calculated and regressed against meteorological variables to characterize the seasonal pattern of mosquito infestation in all cities, as measured by each of the four traps.
  
  
  RESULTS
  The House Index was consistently low in most cities, with median always 0. Traps rarely produced null indices, pointing to their greater sensitivity in detecting the presence of Ae. aegypti in comparison to the larval survey. Trap positivity indices tend to plateau at high mosquito densities. Despite this, both indices, positivity and density, agreed on the seasonality of mosquito abundance in all cities. Mosquito seasonality associated preferentially with temperature than with precipitation even in areas where temperature variation is small.
  
  
  CONCLUSIONS
  All investigated traps performed better than the House Index in measuring the seasonal variation in mosquito abundance and should be considered as complements or alternatives to larval surveys. Choice between traps should further consider differences of cost and ease-of-use.
authors: Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: Claudia T
authors: CT
authors: Codeço
authors: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: Arthur W S
authors: AW
authors: Lima
authors: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: Simone C
authors: SC
authors: Araújo
authors: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: José Bento P
authors: JB
authors: Lima
authors: Laboratório de Transmissores de Hematozoários, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: Rafael
authors: R
authors: Maciel-de-Freitas
authors: Laboratório de Transmissores de Hematozoários, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors: Nildimar A
authors: NA
authors: Honório
authors: Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá-IEPA, Amapá, Brazil.
authors: Allan K R
authors: AK
authors: Galardo
authors: Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasilia, Brazil.
authors: Ima A
authors: IA
authors: Braga
authors: Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasilia, Brazil.
authors: Giovanini E
authors: GE
authors: Coelho
authors: Laboratório de Biologia Molecular de Flavivírus, Fundação Oswaldo Cruz, Rio de Janeiro, and Instituto Nacional de Ciência e Tecnologia-Entomologia Molecular, Brazil.
authors: Denise
authors: D
authors: Valle
mesh_terms: D000330:Aedes / Q000821:virology; D000818:Animals; D001938:Brazil; D065632:Chikungunya Fever / Q000635:transmission; D003715:Dengue / Q000635:transmission; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000821:virology; D008297:Male; D009032:Mosquito Control / Q000379:methods*; D011156:Population Density; D011157:Population Dynamics; D012621:Seasons