title: Entomological aspects and the role of human behaviour in malaria transmission in a highland region of the Republic of Yemen.
abstract: BACKGROUND
  The Republic of Yemen has the highest incidence of malaria in the Arabian Peninsula, yet little is known of its vectors or transmission dynamics.
  
  
  METHODS
  A 24-month study of the vectors and related epidemiological aspects of malaria transmission was conducted in two villages in the Taiz region in 2004-2005.
  
  
  RESULTS
  Cross-sectional blood film surveys recorded an overall malaria infection rate of 15.3 % (250/1638), with highest rates exceeding 30 % in one village in May and December 2005. With one exception, Plasmodium malariae, all infections were P. falciparum. Seven Anopheles species were identified among 3407 anophelines collected indoors using light traps (LT) and pyrethrum knockdown catches (PKD): Anopheles arabiensis (86.9 %), An. sergentii (9 %), An. azaniae, An. dthali, An. pretoriensis, An. coustani and An. algeriensis. Sequences for the standard barcode region of the mitochondrial COI gene confirmed the presence of two morphological forms of An. azaniae, the typical form and a previously unrecognized form not immediately identifiable as An. azaniae. ELISA detected Plasmodium sporozoites in 0.9 % of 2921 An. arabiensis (23 P. falciparum, two P. vivax) confirming this species as the primary malaria vector in Yemen. Plasmodium falciparum sporozoites were detected in An. sergentii (2/295) and a single female of An. algeriensis, incriminating both species as malaria vectors for the first time in Yemen. A vector in both wet and dry seasons, An. arabiensis was predominantly anthropophilic (human blood index = 0.86) with an entomological inoculation rate of 1.58 infective bites/person/year. Anopheles sergentii fed on cattle (67.3 %) and humans (48.3; 20.7 % mixed both species), but only 14.7 % were found in PKDs, indicating predominantly exophilic behaviour. A GIS analysis of geographic and socio-economic parameters revealed that An. arabiensis were significantly higher (P < 0.001) in houses with televisions, most likely due to the popular evening habit of viewing television collectively in houses with open doors and windows.
  
  
  CONCLUSIONS
  The predominantly indoor human biting vectors recorded in this study could be targeted effectively with LLINs, indoor residual spraying and/or insecticide-treated window/door curtains reinforced by education to instil a perception that effective and affordable malaria prevention is achievable.
authors.affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK. samiraal@yahoo.com.|Department of Medical Parasitology, Faculty of Medicine and Health Sciences, University of Yemen, Sana'a, Yemen. samiraal@yahoo.com.
authors.forename: Samira M A
authors.initials: SM
authors.lastname: Al-Eryani
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK. Louise.Kelly-Hope@lstmed.ac.uk.
authors.forename: Louise
authors.initials: L
authors.lastname: Kelly-Hope
authors.affiliation: Department of Life Sciences, Natural History Museum, Cromwell Road, London, UK. R.Harbach@nhm.ac.uk.
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Harbach
authors.affiliation: Department of Life Sciences, Natural History Museum, Cromwell Road, London, UK. A.Briscoe@nhm.ac.uk.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Briscoe
authors.affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK. gbarnish@liverpool.ac.uk.
authors.forename: Guy
authors.initials: G
authors.lastname: Barnish
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine and Health Sciences, University of Yemen, Sana'a, Yemen. ahmedazazy60@hotmail.com.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Azazy
authors.affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK. philip.mccall@lstmed.ac.uk.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: McCall
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission*; D010963:Plasmodium falciparum; D062486:Public Health Surveillance; D012307:Risk Factors; D012919:Social Behavior; D013690:Television; D015006:Yemen / Q000453:epidemiology