Community Hand-Dug Wells for Trachoma: A Cluster-Randomized Trial

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  • 1 The Carter Center Ethiopia, Addis Ababa, Ethiopia;
  • 2 Francis I Proctor Foundation, University of California, San Francisco, San Francisco, California;
  • 3 The Carter Center, Atlanta, Georgia;
  • 4 Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California;
  • 5 Department of Ophthalmology, University of California, San Francisco, San Francisco, California

The WHO recommends improving access to water as part of a comprehensive strategy for elimination of trachoma as a public health problem; however, this recommendation is not based on evidence from randomized trials. In a region of Ethiopia with hyperendemic trachoma, seven communities were randomized to a hand-dug well (HDW) and seven communities to no intervention to determine the impact of HDWs on the community prevalence of ocular chlamydia infection (primary prespecified outcome). All communities continued to receive government hygiene and sanitation services and outreach. Participants were not masked, given the nature of the intervention, but laboratory personnel were masked to treatment allocation. Hand-dug wells were successfully built in six of the seven communities; five of these wells were still functional at the conclusion of the trial. At the end of the trial, an average of 74% of households reported traveling < 30 minutes to collect water in the HDW arm, compared with 45% in the control arm, and the daily volume of water used for hygiene was similar (e.g., mean of 0.7 L per person in each arm). The pseudo-median prevalence of ocular chlamydia among 0- to 50-year old people at the 24-month visit was 23% in the HDW group and 13% in the control group (P > 0.99). This small cluster-randomized trial provided no evidence to suggest that simply constructing HDWs, in the absence of other hygiene promotion activities, is effective for reducing transmission of ocular chlamydia.

Author Notes

Address correspondence to Jeremy D. Keenan, 513 Parnassus Ave., Box 0412, University of California, San Francisco San Francisco, CA 94143. E-mail:

Financial support: The main funders of the trial were That Man May See and the National Eye Institute (grant U10 EY016214). Additional funding was provided by the Bernard Osher Foundation, the Harper Inglis Trust, the Bodri Foundation, the Proctor Foundation’s South Asia Research Fund, and Research to Prevent Blindness. The trachoma control program in Amhara is supported by the Carter Center, Amhara Regional Health Bureau, the Lions-Carter Center SightFirst Initiative, and many individual donors.

Authors’ addresses: Solomon Aragie, Sintayehu Gebresillasie, Ambahun Chernet, Ayalew Shiferaw, Zerihun Tadesse, and Mulat Zerihun, The Carter Center Ethiopia, Addis Ababa, Ethiopia, E-mails:,,,,, and Nicole E. Varnado, Sun Y. Cotter, Dionna M. Wittberg, and Zhaoxia Zhou, Kristen Aiemjoy, and Jeremy D. Keenan, Francis I Proctor Foundation, University of California, San Francisco, San Francisco, CA, E-mails:,,,, and E. Kelly Callahan and Scott D. Nash, The Carter Center, Atlanta, GA, E-mail: and

These authors contributed equally to this work.