title: Evaluation of traps and lures for mosquito vectors and xenomonitoring of Wuchereria bancrofti infection in a high prevalence Samoan Village.
abstract: BACKGROUND
  Elimination of lymphatic filariasis (LF) in Samoa continues to be challenging despite multiple annual mass drug campaigns aimed at stopping transmission by reducing the prevalence and density of microfilaraemia. The persistence of transmission may be partly related to the highly efficient Aedes vectors. The assessment of pathogen transmission by mosquito vectors and of vector control relies on the ability to capture mosquitoes efficiently. The aims of this study are to compare trapping methods to capture LF-infected mosquitoes and determine the role in transmission of the species of Aedes mosquitoes in the area.
  
  
  METHODS
  Fasitoo-Tai village was the chosen site because of persistent transmission despite annual mass drug administration. Sampling methods included BioGents Sentinel (BGS) trap, human-baited collections (HBC) and the Centers for Disease Control (CDC) trap. BGS and CDC traps were baited with BG-lure, CO2, and/or octenol. Individual trap locations were geo-located and efficiency of sampling methods was evaluated using a randomized Latin-square design in two locations. Number of mosquitoes collected (male and female), as well as species for each trapping method were determined. Additionally, Ae. polynesiensis and Ae. (Finlaya) spp. females were pooled by trap method and analysed for filarial DNA. Infection prevalence was estimated using the PoolScreen software.
  
  
  RESULTS
  The BGS trap with any type of bait collected more mosquitoes compared to both the CDC trap and the HBC. The BGS trap baited with BG-lure collected more mosquitoes than with CO2 and octenol. There were no significant differences between trapping methods in terms of proportions of infected females collected. The prevalence of filarial infection in Ae. polynesiensis and Ae. (Finlaya) spp. was estimated at 4.7% and 0.67% respectively.
  
  
  CONCLUSIONS
  This study supports the use of the BGS trap for research on and surveillance of the mosquito vectors of LF in Samoa. The BGS trap is a suitable and safer alternative to HBC for sampling Ae. polynesiensis and Ae. (Finlaya) spp., which continue to be the predominant vectors of LF. Of concern was the high prevalence of LF in mosquitoes despite a recent mass drug administration programme. This highlights the urgency for updated policies concerning filariasis elimination in Samoa.
authors.affiliation: Institut Louis Malardé, Papeete, French Polynesia. lhapairai@yahoo.com.
authors.forename: Limb K
authors.initials: LK
authors.lastname: Hapairai
authors.affiliation: Institut Louis Malardé, Papeete, French Polynesia. cplichart@mail.pf.
authors.forename: Catherine
authors.initials: C
authors.lastname: Plichart
authors.affiliation: Ministry of Health, Apia, Samoa. taken@health.gov.ws.
authors.forename: Take
authors.initials: T
authors.lastname: Naseri
authors.affiliation: Ministry of Health, Apia, Samoa. UalesiS@health.gov.ws.
authors.forename: Ualesi
authors.initials: U
authors.lastname: Silva
authors.affiliation: Ministry of Health, Apia, Samoa. LamekoT@health.gov.ws.
authors.forename: Lameko
authors.initials: L
authors.lastname: Tesimale
authors.affiliation: Ministry of Health, Apia, Samoa. PauloP@health.gov.ws.
authors.forename: Paulo
authors.initials: P
authors.lastname: Pemita
authors.affiliation: Institut Louis Malardé, Papeete, French Polynesia. hbossin@ilm.pf.
authors.forename: Hervé C
authors.initials: HC
authors.lastname: Bossin
authors.affiliation: Australian Institute of Tropical Health and Medicine, James Cook University, Cairns and Townsville, Australia. tom.burkot@jcu.edu.au.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Burkot
authors.affiliation: Australian Institute of Tropical Health and Medicine, James Cook University, Cairns and Townsville, Australia. scott.ritchie@jcu.edu.au.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Ritchie
authors.affiliation: Australian Institute of Tropical Health and Medicine, James Cook University, Cairns and Townsville, Australia. patricia.graves@jcu.edu.au.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Graves
authors.affiliation: Australian Institute of Tropical Health and Medicine, James Cook University, Cairns and Townsville, Australia. wayne.melrose@jcu.edu.au.
authors.forename: Wayne
authors.initials: W
authors.lastname: Melrose
authors.affiliation: Australian Institute of Tropical Health and Medicine, James Cook University, Cairns and Townsville, Australia. joseph.h@wehi.edu.au.|Current address: Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3053, Australia. joseph.h@wehi.edu.au.
authors.forename: Hayley
authors.initials: H
authors.lastname: Joseph
mesh_terms: D000330:Aedes / Q000469:parasitology*; D000818:Animals; D004605:Elephantiasis, Filarial / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control* / Q000635:transmission; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D008297:Male; D009032:Mosquito Control / Q000295:instrumentation / Q000379:methods*; D015995:Prevalence; D012423:Rural Health; D018947:Samoa / Q000453:epidemiology; D014958:Wuchereria bancrofti / Q000502:physiology*