title: Resting and feeding preferences of Anopheles stephensi in an urban setting, perennial for malaria.
abstract: The Indian city of Chennai is endemic for malaria and the known local malaria vector is Anopheles stephensi. Plasmodium vivax is the predominant malaria parasite species, though Plasmodium falciparum is present at low levels. The urban ecotype of malaria prevails in Chennai with perennial transmission despite vector surveillance by the Urban Malaria Scheme (UMS) of the National Vector Borne Disease Control Programme (NVBDCP). Understanding the feeding and resting preferences, together with the transmission potential of adult vectors in the area is essential in effective planning and execution of improved vector control measures.
  
  
  
  A yearlong survey was carried out in cattle sheds and human dwellings to check the resting, feeding preferences and transmission potential of An. stephensi. The gonotrophic status, age structure, resting and host seeking preferences were studied. The infection rate in An. stephensi and Anopheles subpictus were analysed by circumsporozoite ELISA (CS-ELISA).
  
  
  
  Adult vectors were found more frequently and at higher densities in cattle sheds than human dwellings. The overall Human Blood Index (HBI) was 0.009 indicating the vectors to be strongly zoophilic. Among the vectors collected from human dwellings, 94.2% were from thatched structures and the remaining 5.8% from tiled and asbestos structures. 57.75% of the dissected vectors were nulliparous whereas, 35.83% were monoparous and the rest 6.42% biparous. Sporozoite positivity rate was 0.55% (4/720) and 1.92% (1/52) for An. stephensi collected from cattle sheds and human dwellings, respectively. One adult An. subpictus (1/155) was also found to be infected with P. falciparum.
  
  
  
  Control of the adult vector populations can be successful only by understanding the resting and feeding preferences. The present study indicates that adult vectors predominantly feed on cattle and cattle sheds are the preferred resting place, possibly due to easy availability of blood meal source and lack of any insecticide or repellent pressure. Hence targeting these resting sites with cost effective, socially acceptable intervention tools, together with effective larval source management to reduce vector breeding, could provide an improved integrated vector management strategy to help drive down malaria transmission and assist in India's plan to eliminate malaria by 2030.
authors.affiliation: IDVC Field Unit, National Institute of Malaria Research (ICMR), NIE Campus, 2nd Main Road, TNHB, Ayapakkam, Chennai, 600 077, India.
authors.forename: Shalu
authors.initials: S
authors.lastname: Thomas
authors.affiliation: IDVC Field Unit, National Institute of Malaria Research (ICMR), NIE Campus, 2nd Main Road, TNHB, Ayapakkam, Chennai, 600 077, India.
authors.forename: Sangamithra
authors.initials: S
authors.lastname: Ravishankaran
authors.affiliation: IDVC Field Unit, National Institute of Malaria Research (ICMR), NIE Campus, 2nd Main Road, TNHB, Ayapakkam, Chennai, 600 077, India.
authors.forename: N A Johnson Amala
authors.initials: NA
authors.lastname: Justin
authors.affiliation: IDVC Field Unit, National Institute of Malaria Research (ICMR), NIE Campus, 2nd Main Road, TNHB, Ayapakkam, Chennai, 600 077, India.
authors.forename: Aswin
authors.initials: A
authors.lastname: Asokan
authors.affiliation: Department of Zoology, Madras Christian College, Tambaram, Chennai, 600 059, India.
authors.forename: Manu Thomas
authors.initials: MT
authors.lastname: Mathai
authors.affiliation: National Institute of Malaria Research (ICMR), Sector 8, Dwarka, New Delhi, 110 077, India.
authors.forename: Neena
authors.initials: N
authors.lastname: Valecha
authors.affiliation: Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA.
authors.forename: Jacqui
authors.initials: J
authors.lastname: Montgomery
authors.affiliation: Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Thomas
authors.affiliation: IDVC Field Unit, National Institute of Malaria Research (ICMR), NIE Campus, 2nd Main Road, TNHB, Ayapakkam, Chennai, 600 077, India. alexeapen@yahoo.com.
authors.forename: Alex
authors.initials: A
authors.lastname: Eapen
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology / Q000502:physiology*; D001522:Behavior, Animal; D002417:Cattle; D002947:Cities / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005247:Feeding Behavior; D005260:Female; D006798:Housing; D006799:Housing, Animal; D006801:Humans; D007194:India / Q000453:epidemiology; D008288:Malaria / Q000453:epidemiology*; D010961:Plasmodium / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000032:analysis; D011795:Surveys and Questionnaires
chemical_list: D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan
keywords: Anopheles stephensi; Blood meal analysis; Parity; Urban malaria; Vector control