title: Chrysomya putoria, a putative vector of diarrheal diseases.
abstract: BACKGROUND
  Chrysomya spp are common blowflies in Africa, Asia and parts of South America and some species can reproduce in prodigious numbers in pit latrines. Because of their strong association with human feces and their synanthropic nature, we examined whether these flies are likely to be vectors of diarrheal pathogens.
  
  
  RESULTS
  Flies were sampled using exit traps placed over the drop holes of latrines in Gambian villages. Odor-baited fly traps were used to determine the relative attractiveness of different breeding and feeding media. The presence of bacteria on flies was confirmed by culture and bacterial DNA identified using PCR. A median of 7.00 flies/latrine/day (IQR = 0.0-25.25) was collected, of which 95% were Chrysomya spp, and of these nearly all were Chrysomya putoria (99%). More flies were collected from traps with feces from young children (median = 3.0, IQR = 1.75-10.75) and dogs (median = 1.50, IQR = 0.0-13.25) than from herbivores (median = 0.0, IQR = 0.0-0.0; goat, horse, cow and calf; p<0.001). Flies were strongly attracted to raw meat (median = 44.5, IQR = 26.25-143.00) compared with fish (median = 0.0, IQR = 0.0-19.75, ns), cooked and uncooked rice, and mangoes (median = 0.0, IQR = 0.0-0.0; p<0.001). Escherichia coli were cultured from the surface of 21% (15/72 agar plates) of Chrysomya spp and 10% of these were enterotoxigenic. Enteroaggregative E. coli were identified by PCR in 2% of homogenized Chrysomya spp, Shigella spp in 1.4% and Salmonella spp in 0.6% of samples.
  
  
  CONCLUSIONS
  The large numbers of C. putoria that can emerge from pit latrines, the presence of enteric pathogens on flies, and their strong attraction to raw meat and fish suggests these flies may be common vectors of diarrheal diseases in Africa.
authors.affiliation: School of Biological and Biomedical Sciences, Durham University, Durham City, United Kingdom. S.W.Lindsay@durham.ac.uk
authors.forename: Steven W
authors.initials: SW
authors.lastname: Lindsay
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Lindsay
authors.forename: Jessica
authors.initials: J
authors.lastname: Duprez
authors.forename: Martin J R
authors.initials: MJ
authors.lastname: Hall
authors.forename: Brenda A
authors.initials: BA
authors.lastname: Kwambana
authors.forename: Musa
authors.initials: M
authors.lastname: Jawara
authors.forename: Ikumapayi U
authors.initials: IU
authors.lastname: Nurudeen
authors.forename: Neneh
authors.initials: N
authors.lastname: Sallah
authors.forename: Nigel
authors.initials: N
authors.lastname: Wyatt
authors.forename: Umberto
authors.initials: U
authors.lastname: D'Alessandro
authors.forename: Margaret
authors.initials: M
authors.lastname: Pinder
authors.forename: Martin
authors.initials: M
authors.lastname: Antonio
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology; D004175:Diptera / Q000382:microbiology* / Q000502:physiology*; D004199:Disease Vectors; D004285:Dogs; D004755:Enterobacteriaceae / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D005243:Feces; D005502:Food; D005714:Gambia; D006801:Humans; D016133:Polymerase Chain Reaction; D012418:Ruminants