Comparing the effectiveness of shared versus private latrines in preventing trachoma in rural Tanzania.

Sharing latrines is common in sub-Saharan Africa with anecdotal accounts suggesting a link between water-, sanitation-, and hygiene-related disease and poorly maintained communal latrines. This study examines this link by assessing the association between shared latrines compared with private latrines and risk of trachoma. In 2007, as part of a larger case-control study, we conducted a sub-study on latrine sharing in 594 households (92 cases, 502 controls) in seven rural Tanzanian communities. Case households were defined by having a child with clinical signs of trachoma. Latrine use was associated with a decreased risk of trachoma and there was no difference in risk between households using shared compared with private latrines (adjusted odds ratio = 0.95 [95% confidence interval = 0.55-1.67]). This study emphasizes the need to promote latrine use, which can be facilitated through latrine sharing in resource scarce areas, for prevention of trachoma.