Household pit latrines as a potential source of the fly Musca sorbens--a one year longitudinal study from The Gambia.
OBJECTIVE
To assess whether the trachoma vector Musca sorbens was breeding in household latrines in a trachoma-endemic part of The Gambia.


METHODS
Longitudinal study of flies emerging from 16 sentinel household latrines selected at random from a list of all latrines present in four Gambian villages. Latrines were surveyed and fly traps were set over the drop hole for 24 h once per month for a year.


RESULTS
All the sentinel latrines were of the 'Gambian improved household latrine' design, which has a cement slab but is not ventilated or fly-proofed. The latrines were all in regular use by a family, mean number of users per latrine 14.8 (SD 8.0, range 2-29). Of 55 351 flies caught in 192 catches 54 130 (97.8%) were Chrysomya albiceps, 690 (1.2%) Musca domestica, 466 (0.8%) Chrysomya regalis and 65 (0.1%) M. sorbens. Of the M. sorbens caught 61 (93.8%) were female.


CONCLUSIONS
Gambian improved household pit latrines cannot be considered a source of the trachoma vector M. sorbens, and the promotion of pit latrines as a method to reduce M. sorbens is warranted. A large number of C. albiceps were caught emerging from the latrines, but this species is not considered to be of medical importance.
Emerson
Paul M
PM
School of Biological and Biomedical Science, University of Durham, Durham, UK. paul.emerson@emory.edu
Simms
Victoria M
VM
Makalo
Pateh
P
Bailey
Robin L
RL
D000818:Animals; D004867:Equipment Design; D005260:Female; D005714:Gambia / Q000453:epidemiology; D006306:Health Surveys; D006798:Housing; D006801:Humans; D007303:Insect Vectors / Q000254:growth & development*; D008137:Longitudinal Studies; D009117:Muscidae / Q000254:growth & development*; D014038:Toilet Facilities; D014141:Trachoma / Q000453:epidemiology / Q000635:transmission*