Use of Household Water Treatment and Safe Storage Methods in Acute Emergency Response: Case Study Results from Nepal, Indonesia, Kenya, and Haiti

Abstract

Household water treatment (HWTS) methods, such as boiling or chlorination, have long been recommended in emergencies. While there is increasing evidence of HWTS efficacy in the development context, effectiveness in the acute emergency context has not been rigorously assessed. We investigated HWTS effectiveness in response to four acute emergencies by surveying 1521 targeted households and testing stored water for free chlorine residual and fecal indicators. We defined "effective use" as the percentage of the targeted population with contaminated household water who used the HWTS method to improve stored drinking water microbiological quality to internationally accepted levels. Chlorine-based methods were distributed in all four emergencies and filters in one emergency. Effective use ranged widely, from 0-67.5%, with only one pre-existing chlorine program in Haiti and unpromoted boiling use in Indonesia reaching >20%. More successful programs provided an effective HWTS method, with the necessary supplies and training provided, to households with contaminated water who were familiar with the method before the emergency. HWTS can be effective at reducing the risk of unsafe drinking water in the acute emergency context. Additionally, by focusing on whether interventions actually improve drinking water quality in vulnerable households, "effective use" provides an important program evaluation metric.

Household Water Treatment Uptake during a Public Health Response to a Large Typhoid Fever Outbreak in Harare, Zimbabwe

“…Previous research in Table 3 Ability and motivation behavioral factors associated with typhoid fever outbreak and household water treatment among survey respondents, Dzivaresekwa and Kuwadzana suburbs, Harare, Zimbabwe, March 2012 (N = 457*) emergency contexts has documented that higher uptake of HWTS is associated with distribution of an effective HWTS method, including the necessary supplies and training, to households with contaminated water who were familiar with the HWTS method before the emergency. 10 The launch of WaterGuard following the 2008-09 cholera outbreak in Zimbabwe raised awareness of household water treatment and provided Harare residents with long-term access to a product marketed for that purpose. However, although we documented high awareness of WaterGuard and high reported coverage of the educational and HWTS product distribution campaigns in the two suburbs most affected by the outbreak, reported treatment on the day of an unannounced visit was low, FCR levels in reportedly treated water were often inadequate, and the knowledge of chlorine tablet dosage (tablets per volume of water) was frequently inaccurate, which suggested confusion about correct use during emergencies.…”

“…Sample size calculations for similar studies suggested a sample size of 200 per program or community was suitable for identifying household-level differences between HWTS users and non-users. 10 Using maps to create a sampling frame, 250 housing units (to account for non-responses) were randomly selected from each of the two suburbs, Kuwadzana and Dzivaresekwa. A housing unit was defined as a single housing structure.…”

“…6 Household water treatment and safe storage (HWTS) with sodium hypochlorite (chlorine) solution is a proven, lowcost intervention that improves the microbiological quality of drinking water in developing countries and significantly reduces morbidity caused by waterborne diseases. [7][8][9][10] Household water chlorination has also been used in emergency response, including responses to waterborne disease outbreaks, with variable success. 10,11 Following the massive cholera outbreak in [2008][2009] in Zimbabwe, the U.S. Agency for International Development's Office of U.S. Foreign Disaster Assistance (USAID/OFDA) supported Population Services International (PSI) to establish local production and social marketing of WaterGuard-1.25% sodium hypochlorite solution for household water treatment-throughout Zimbabwe to reduce the risk of subsequent waterborne disease outbreaks.…”

Effective Use of Household Water Treatment and Safe Storage in Response to the 2010 Haiti Earthquake

“…Although direct assessments of health impact are rarely possible in the critical early stages of an emergency, it is nevertheless important to target interventions to those people at risk and provide them with solutions to mitigate that risk. In this evaluation, we use the metric effective use 20 to capture the extent to which the HWTS method (1) reached a population at risk from waterborne disease and (2) was actually used by that population to reduce their risk. Effective use is, thus, the percent of targeted households with water that was microbiologically contaminated that used the intervention to improve their water quality to internationally accepted standards.…”

Short-term WASH interventions in emergency response: a systematic review

“…Lantagne and Clasen (2012) and Yates et al (2015) are two examples of non-experimental design field research that draws strength from consistency, rather than evaluation methodology. Both papers utilized the same or similar evaluations in different contexts to highlight differences in use and also barriers and facilitators for a specific intervention.…”