title: Sibling species of the Anopheles funestus group, and their infection with malaria and lymphatic filarial parasites, in archived and newly collected specimens from northeastern Tanzania.
abstract: BACKGROUND
  Studies on the East African coast have shown a recent dramatic decline in malaria vector density and change in composition of sibling species of the Anopheles gambiae complex, paralleled by a major decline in malaria incidence. In order to better understand the ongoing changes in vector-parasite dynamics in the area, and to allow for appropriate adjustment of control activities, the present study examined the composition, and malaria and lymphatic filarial infection, of sibling species of the Anopheles funestus group. Similar to the An. gambiae complex, the An. funestus group contains important vectors of both malaria and lymphatic filariasis.
  
  
  METHODS
  Archived (from 2005-2012) and newly collected (from 2014) specimens of the An. funestus group collected indoors using CDC light traps in villages in northeastern Tanzania were analysed. They were identified to sibling species by PCR based on amplification of species-specific nucleotide sequence in the ITS2 region on rDNA genes. The specimens were furthermore examined for infection with Plasmodium falciparum and Wuchereria bancrofti by PCR.
  
  
  RESULTS
  The identified sibling species were An. funestus s.s., Anopheles parensis, Anopheles rivulorum, and Anopheles leesoni, with the first being by far the most common (overall 94.4%). When comparing archived specimens from 2005-2007 to those from 2008-2012, a small but statistically significant decrease in proportion of An. funestus s.s. was noted, but otherwise observed temporal changes in sibling species composition were minor. No P. falciparum was detected in archived specimens, while 8.3% of the newly collected An. funestus s.s. were positive for this parasite. The overall W. bancrofti infection rate decreased from 14.8% in the 2005-2007 archived specimens to only 0.5% in the newly collected specimens, and with overall 93.3% of infections being in An. funestus s.s.
  
  
  CONCLUSIONS
  The study indicated that the composition of the An. funestus group had remained rather stable during the study period, with An. funestus s.s. being the most predominant. The study also showed increasing P. falciparum infection and decreasing W. bancrofti infection in An. funestus s.s. in the study period, most likely reflecting infection levels with these parasites in the human population in the area.
authors.affiliation: National Institute for Medical Research, Amani Research Centre, P.O. Box 81, Muheza, Tanga, Tanzania. yahyaathman@yahoo.com.
authors.forename: Yahya A
authors.initials: YA
authors.lastname: Derua
authors.affiliation: Centre for Medical Parasitology, Institute of International Health, Immunology, and Microbiology, University of Copenhagen, Copenhagen, Denmark. micali@sund.ku.dk.
authors.forename: Michael
authors.initials: M
authors.lastname: Alifrangis
authors.affiliation: National Institute for Medical Research, Amani Research Centre, P.O. Box 81, Muheza, Tanga, Tanzania. smagesa@rti.org.|Global Health Division, RTI International, Dar es Salaam, Tanzania. smagesa@rti.org.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Magesa
authors.affiliation: National Institute for Medical Research, Amani Research Centre, P.O. Box 81, Muheza, Tanga, Tanzania. wkisinza@nimr.or.tz.
authors.forename: William N
authors.initials: WN
authors.lastname: Kisinza
authors.affiliation: Department of Veterinary Disease Biology, Section for Parasitology and Aquatic Diseases, University of Copenhagen, Copenhagen, Denmark. pesi@sund.ku.dk.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Simonsen
mesh_terms: D000818:Animals; D000852:Anopheles / Q000145:classification / Q000235:genetics* / Q000469:parasitology*; D004605:Elephantiasis, Filarial / Q000635:transmission*; D008288:Malaria / Q000635:transmission*; D013636:Tanzania