Family latrines and paediatric shigellosis in rural Bangladesh: benefit or risk?

BACKGROUND: The potential benefits of installing excreta disposal facilities on the burden of paediatric diarrhoea in less-developed settings remain controversial. We conducted a longitudinal study to evaluate whether family latrines are associated with interruption of the transmission of shigellosis to younger children in rural Bangladesh.
METHODS: We prospectively studied 1529 children under 5 years of age exposed to index cases of Shigella dysentery. In all 219 children with culture-proven shigellosis detected during 1 month of follow-up were compared with 1310 control children who did not develop shigellosis or Shigella-negative dysentery.
RESULTS: Overall, the presence of a family latrine appeared to be associated with a higher, not a lower, risk of paediatric shigellosis (adjusted odds ratio (ORa) = 1.37, 95% confidence interval (CI): 0.99-1.89). While use of a pit or sanitary latrine revealed no evidence of a protective association (ORa = 0.96, 95% CI: 0.43-2.15), use of a hanging latrine in which faeces were discharged directly onto the ground or into a body of water was associated with a notable increase of risk (ORa = 1.42, 95% CI: 1.02-1.98, P < 0.05).
CONCLUSIONS: While cautioning that installation of sanitary latrines may not be sufficient to reduce the burden of paediatric shigellosis in less-developed settings, these data suggest that eliminating unsanitary latrines constitutes a potentially important intervention in its own right in these settings.