title: Role of underappreciated vectors in malaria transmission in an endemic region of Bangladesh-India border.
abstract: BACKGROUND
  Despite the efforts of the National Malaria Control Programme, malaria remains as an important public health problem in Bangladesh, particularly in the south-eastern region bordering India. Successful malaria control strategies rely on a detailed understanding of the underlying causes of malaria transmission. Here, an entomological survey was conducted in a malaria endemic area of Bangladesh bordering India to investigate the Anopheles mosquito community and assess their Plasmodium infection status.
  
  
  METHODS
  Monthly entomological collections were undertaken from October 2010 to September 2011 in five villages in the Matiranga sub-district, Khagrachari district in Bangladesh, bordering the Indian State of Tripura. CDC miniature light traps were placed inside houses to collect adult Anopheles mosquitoes. Following morphological and molecular identification of the female Anopheles mosquitoes collected, they were screened for circumsporozoite proteins (CSP) of Plasmodium falciparum (Pf), Plasmodium vivax-210 (Pv-210) and Plasmodium vivax-247 (Pv-247), by ELISA to determine natural infection rates. Variation in Anopheles species composition, relative abundance and Plasmodium infection rates were analysed between sampled villages.
  
  
  RESULTS
  A total of 2,027 female Anopheles were collected, belonging to 20 species. Anopheles nivipes was the most abundant species in our test villages during the peak malaria transmission season, and was observed sympatrically with An. philippinensis in the studied area. However, in the dry off-peak season, An. jeyporiensis was the most abundant species. Shannon's diversity index was highest in October (2.12) and evenness was highest in May (0.91). The CSP ELISA positive rate overall was 0.44%. Anopheles karwari (n=2), An. barbirostris s.l. (n=1) and An. vagus (n=1) were recorded positive for Pf. Anopheles kochi (n=1) was positive for Pv-210 while An. umbrosus (n=1), An. nivipes (n=1) and An. kochi (n=1) were positive for Pv-247. A mixed infection of Pf and Pv-247 was detected in An. barbirostris s.l..
  
  
  CONCLUSIONS
  High diversity of Anopheles species was observed in areas close to the international border where species that were underestimated for malaria transmission significantly outnumbered principal vector species and these may play a significantly heightened role in malaria transmission.
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. alamin@icddrb.org.
authors.forename: Hasan Mohammad
authors.initials: HM
authors.lastname: Al-Amin
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. rubayet@vt.edu.|Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24061, USA. rubayet@vt.edu.
authors.forename: Rubayet
authors.initials: R
authors.lastname: Elahi
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. manmohon@ucalgary.ca.|Department of Microbiology and Infectious Disease, Cumming School of Medicine, University of Calgary, Alberta, T2N1N4, Canada. manmohon@ucalgary.ca.
authors.forename: Abu Naser
authors.initials: AN
authors.lastname: Mohon
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. kafi@icddrb.org.
authors.forename: Mohammad Abdullah Heel
authors.initials: MA
authors.lastname: Kafi
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. sumit@icddrb.org.
authors.forename: Sumit
authors.initials: S
authors.lastname: Chakma
authors.affiliation: Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. jennieslord@gmail.com.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Lord
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. wakhan@icddrb.org.
authors.forename: Wasif A
authors.initials: WA
authors.lastname: Khan
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. rhaque@icddrb.org.
authors.forename: Rashidul
authors.initials: R
authors.lastname: Haque
authors.affiliation: Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21205, USA. douglas.norris@jhu.edu.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Norris
authors.affiliation: International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh. shafiul@icddrb.org.
authors.forename: Mohammad Shafiul
authors.initials: MS
authors.lastname: Alam
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D001459:Bangladesh; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007194:India; D007303:Insect Vectors / Q000469:parasitology*; D008288:Malaria / Q000635:transmission*; D010961:Plasmodium / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000378:metabolism; D012621:Seasons; D013045:Species Specificity
chemical_list: D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan