title: Evaluation of CDC light traps for mosquito surveillance in a malaria endemic area on the Thai-Myanmar border.
abstract: BACKGROUND
  Centers for Disease Control and Prevention miniature light traps (CDC-LT) baited with CO2 are a routine tool for adult mosquito sampling used in entomological surveys, and for monitoring and surveillance of disease vectors. The present study was aimed at evaluating the performance of baited and unbaited CDC-LT for indoor and outdoor trapping of endemic mosquito species in northwestern Thailand.
  
  
  METHODS
  CDC-LT (n = 112) with and without dry ice baits were set both indoors and outdoors in 88 selected houses for stretches of 5 consecutive nights per month in 7 villages in Tha Song Yang district, Tak province between January 2011 and March 2013. Individual traps were repeatedly placed in the same location for a median of 6 (range 1-10) times. Mosquitoes were identified by morphological characteristics and classified into blood-fed, empty, male/female and gravid. Absolute mosquito numbers were converted to capture rates (i.e., mosquitoes per trap and year). Capture rates were compared using multilevel negative binomial regression to account for multiple trap placements and adjust for regional and seasonal differences.
  
  
  RESULTS
  A total of 6,668 mosquitoes from 9 genera were collected from 576 individual CDC-LT placements. Culex was the predominant captured genus (46%), followed by anopheline mosquitoes (45%). Overall, CO2 baited traps captured significantly more Culex (especially Culex vishnui Theobald) and Anopheles mosquitoes per unit time (adjusted capture rate ratio (aCRR) 1.64 and 1.38, respectively). Armigeres spp. mosquitoes were trapped in outdoor traps with significantly higher frequency (aCRR: 1.50), whereas Aedes albopictus (Skuse) had a tendency to be trapped more frequently indoors (aCRR: 1.89, p = 0.07). Furthermore, capture rate ratios between CO2 baited and non-baited CDC-LT were significantly influenced by seasonality and indoor vs. outdoor trap placement.
  
  
  CONCLUSIONS
  The present study shows that CDC-LT with CO2 baiting capture significantly more Culex and Anopheles mosquitoes, some of which (e.g., Cx. vishnui, Cx. quinquefasciatus Say, An. minimus s.l. Theobald, An. maculatus s.l. Theobald) represent important disease vectors in Thailand. This study also shows significant differences in the capture efficiency of CDC-LT when placed indoors or outdoors and in different seasons. Our study thus provides important guidelines for more targeted future vector trapping studies on the Thai-Myanmar border, which is an important cross-border malaria transmission region in Thailand.
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Patchara.sri@mahidol.ac.th.
authors.forename: Patchara
authors.initials: P
authors.lastname: Sriwichai
authors.affiliation: Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia. karl@wehi.edu.au.
authors.forename: Stephan
authors.initials: S
authors.lastname: Karl
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Yudthana.sam@mahidol.ac.th.
authors.forename: Yudthana
authors.initials: Y
authors.lastname: Samung
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Suchada.sum@mahidol.ac.th.
authors.forename: Suchada
authors.initials: S
authors.lastname: Sumruayphol
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Kirakorn.kia@mahidol.ac.th.|Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Kirakorn.kia@mahidol.ac.th.
authors.forename: Kirakorn
authors.initials: K
authors.lastname: Kiattibutr
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Anon.pay@mahidol.ac.th.
authors.forename: Anon
authors.initials: A
authors.lastname: Payakkapol
authors.affiliation: Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia. mueller@wehi.edu.au.
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
authors.affiliation: Program in Public Health, University of California, Irvine, CA, USA. guiyuny@uci.edu.
authors.forename: Guiyun
authors.initials: G
authors.lastname: Yan
authors.affiliation: Department of Entomology, Pennsylvania State University, University Park, PA, USA. luc2@psu.edu.
authors.forename: Liwang
authors.initials: L
authors.lastname: Cui
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. jetsumon.pra@mahidol.edu.
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
mesh_terms: D000818:Animals; D009033:Culicidae / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development* / Q000502:physiology; D019353:Endemic Diseases; D004772:Entomology / Q000379:methods*; D062665:Epidemiological Monitoring; D005247:Feeding Behavior; D005260:Female; D007303:Insect Vectors; D008027:Light; D008288:Malaria / Q000453:epidemiology; D008297:Male; D002052:Myanmar / Q000453:epidemiology; D013785:Thailand / Q000453:epidemiology