Ascaris and Escherichia coli Inactivation in an Ecological Sanitation System in Port-au-Prince, Haiti

• Type of Material: Article
• Authors: David Berendes, Emory University; Karen Levy, Emory University; Thomas Handzel, Centers for Disease Control and Prevention; Vincent Hill, Emory University
• Language: English
• Date: 2015-05-01
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: This is an open access article, free of all copyright.
• License: Creative Commons Creative Commons CC0 1.0 Universal
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0125336
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 10
• Issue: 5
• Start Page: e0125336
• End Page: e0125336
• Grant/Funding Information: This article published with support from Emory Libraries' Open Access Publishing Fund.; Materials, salaries, travel, and logistics for this work were supported by funds from the Emergency Response and Recovery Branch in the Division of Global Health Protection and the Environmental Microbiology Laboratory of the Waterborne Disease Prevention Branch in the Division of Food, Waterborne, and Environmental Diseases at the Centers for Disease Control and Prevention.
• Research Categories: Health Sciences, Public Health; Biology, Microbiology

Abstract

The goal of this study was to evaluate the microbial die-off in a latrine waste composting system in Port-au-Prince, Haiti. Temperature data and samples were collected from compost aged 0 – 12+ months. Samples collected from compost bin centers and corners at two depths were assessed for moisture content, E. coli concentration, and Ascaris spp. viability. Center temperatures in compost bins were all above 58 °C, while corner temperatures were 10 – 20 °C lower. Moisture content was 67 ± 10% in all except the oldest compost. A 4-log reduction in E. coli was observed over the first sixteen weeks of composting at both locations and depths, after which E. coli was undetectable (LOD: 142 MPN g-1 dry weight). In new compost, 10.4% and 8.3% of Ascaris eggs were viable and fully embryonated, respectively. Percent viability dropped to zero in samples older than six weeks. These findings indicate that the Haitian EcoSan composting process was effective in inactivating E. coli and Ascaris spp. in latrine waste within sixteen weeks. This study is one of the first to document efficacy of an ecological sanitation system under field conditions and provides insight into composting methods and monitoring for other international settings.