M C Alves1, N N da Silva. 1. Divisão de Orientação Técnica, Superintendência de Controle de Endemias, São Paulo, SP, Brasil. cecilia@sucen.sp.gov.br
Abstract
OBJECTIVE: To suggest changes in the sampling procedures for estimating the larval density of Aedes aegypti in the state of São Paulo, Brazil, by assessing the efficacy and level of complexity of the current procedures. METHODS: The "Superintendência de Controle de Endemias do Estado de São Paulo" - SUCEN's (Superintendence for Endemic Control of the State of São Paulo) sampling procedures for estimating the density of Aedes aegypti larvae was assessed. The Breteau index with one-stage cluster sampling was applied. An average of 35 blocks, 14 buildings per block, of a total of 510 buildings per sample, were assessed. One hundred and eleven samples were obtained in 6 municipalities of São José do Rio Preto. RESULTS: The Breteau index estimates higher than 3 had coefficients of variation smaller than 30% in 71% of the samples. The design effect was 1.19 and 1.79 for indexes lower and higher than 5, respectively. The estimates were obtained in less than 3 days, requiring a daily average of 5.5 men per sampling. CONCLUSION: This sampling design revealed to be a simplified one: fast, economic and easily managed. The operational easiness was due to the use of the one-stage cluster sampling, when there was not need to prepare lists of addresses and then sort and locate the buildings. Though the design effect shows a slight loss of the estimates' accuracy with the use of one-stage cluster sampling, this was proven to be under acceptable range. Simplifying changes in the process of determining the sample size and assessing sampling errors are proposed.
OBJECTIVE: To suggest changes in the sampling procedures for estimating the larval density of Aedes aegypti in the state of São Paulo, Brazil, by assessing the efficacy and level of complexity of the current procedures. METHODS: The "Superintendência de Controle de Endemias do Estado de São Paulo" - SUCEN's (Superintendence for Endemic Control of the State of São Paulo) sampling procedures for estimating the density of Aedes aegypti larvae was assessed. The Breteau index with one-stage cluster sampling was applied. An average of 35 blocks, 14 buildings per block, of a total of 510 buildings per sample, were assessed. One hundred and eleven samples were obtained in 6 municipalities of São José do Rio Preto. RESULTS: The Breteau index estimates higher than 3 had coefficients of variation smaller than 30% in 71% of the samples. The design effect was 1.19 and 1.79 for indexes lower and higher than 5, respectively. The estimates were obtained in less than 3 days, requiring a daily average of 5.5 men per sampling. CONCLUSION: This sampling design revealed to be a simplified one: fast, economic and easily managed. The operational easiness was due to the use of the one-stage cluster sampling, when there was not need to prepare lists of addresses and then sort and locate the buildings. Though the design effect shows a slight loss of the estimates' accuracy with the use of one-stage cluster sampling, this was proven to be under acceptable range. Simplifying changes in the process of determining the sample size and assessing sampling errors are proposed.
Authors: Lígia Leandro Nunes Serpa; Gisela Rita Alvarenga Monteiro Marques; Ana Paula de Lima; Júlio Cesar Voltolini; Marylene de Brito Arduino; Gerson Laurindo Barbosa; Valmir Roberto Andrade; Virgília Luna Castor de Lima Journal: Parasit Vectors Date: 2013-11-06 Impact factor: 3.876
Authors: Juliana Álvares; Maria Cecilia Goi Porto Alves; Maria Mercedes Loureiro Escuder; Alessandra Maciel Almeida; Jans Bastos Izidoro; Augusto Afonso Guerra; Karen Sarmento Costa; Ediná Alves Costa; Ione Aquemi Guibu; Orlando Mario Soeiro; Silvana Nair Leite; Margô Gomes de Oliveira Karnikowski; Francisco de Assis Acurcio Journal: Rev Saude Publica Date: 2017-11-13 Impact factor: 2.106
Authors: Maria Cecilia Goi Porto Alves; Maria Mercedes Loureiro Escuder; Moises Goldbaum; Marilisa Berti de Azevedo Barros; Regina Mara Fisberg; Chester Luiz Galvão Cesar Journal: Rev Saude Publica Date: 2018-09-03 Impact factor: 2.106