Difficulties in Bringing Point-of-Use Water Treatment to Scale in Rural Guatemala Stephen P. Luby,* Carlos Mendoza, Bruce H. Keswick, Tom M. Chiller, and R. Mike Hoekstra Enteric Diseases Epidemiology Branch, Division of Foodborne Bacterial and Mycotic Diseases, National Center for Zoonotic, Vectorborne and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; Universidad del Valle de Guatemala, Medical Entomology Research and Training Unit, Guatemala City, Guatemala; Procter and Gamble Company, Cincinnati, Ohio Abstract. In an earlier study in rural Guatemala, 257 households that received flocculant-disinfectant to treat their drinking water had 39% less diarrhea than 257 control households. Three weeks after completion of the study, national marketing of the flocculant-disinfectant was extended into the study communities. Six months later, we assessed fre- quency of and characteristics associated with purchase and use of the flocculant-disinfectant by revisiting the original study households and administering a questionnaire. Four hundred sixty-two households (90%) completed the follow-up survey; 22 households (5%) purchased the flocculant-disinfectant within the preceding 2 weeks and used it within the last week. Neither being randomized to the intervention group during the efficacy study nor combined spending on laundry soap, toothpaste, and hand soap in the preceding week was associated with active repeat use. Even after efficacy was demonstrated within their community and an aggressive sophisticated marketing approach, few households purchased flocculant-disinfectant for point-of-use water treatment. INTRODUCTION The World Health Organization (WHO) estimates that 1.1 billion people lack access to an improved water supply. 1 Even if the ambitious millennium development goal of reducing by half the proportion of people without sustainable access to safe drinking water is achieved, several hundred million people will still be dependent on an unimproved drinking water supply in 2015. Historically, extending improved water infrastructure to low-income households has proven difficult. Between 1990 and 2000, although the proportion of house- holds with an improved water supply increased, the number of persons without improved water remained unchanged be- cause of the continued growth of impoverished populations. 1 Moreover, many water supplies that meet the WHO defini- tion of improved are frequently heavily contaminated with human fecal organisms. 2–5 Thus, the number of persons ex- posed to microbiologically unsafe water far exceeds 1.1 bil- lion. This contaminated water contributes importantly to the estimated 2 million persons who die of diarrhea and typhoid fever each year. 6–8 One approach to bring more rapid improvement to house- holds with microbiologically unsafe drinking water is to treat water at the point of use. Various technical approaches have been deployed including chemical treatment, solar irradia- tion, filtration, and combined approaches. 9,10 Numerous small-scale efficacy studies have evaluated point-of-use water treatment. Such studies consistently show that, in settings where diarrhea is a leading cause of death, persons who live in households that regularly treat their drinking water with an approach that is microbiologically effective have less diarrhea than persons living in households that do not treat their drink- ing water at the point of use. 11 Indeed, the strength of the evidence has led WHO to conclude that point-of-use water treatment is the most cost-effective approach to reach the millennium development goal of halving the number of per- sons with no access to safe water. 12 However, efficacy studies are artificial experiments. Typi- cally, study participants are given water treatment supplies at no cost and are aggressively encouraged to use them. Limited data are available on household water treatment outside of efficacy studies. One exception is an independent evaluation of the longest running national point-of-use water treatment program that subsidizes and markets dilute sodium hypochlo- rite under the brand name Clorin in Zambia. During the time of year of the highest sales of Clorin, among households in districts that received considerable social marketing and had the highest per capita sales of Clorin, only 13% of households had residual chlorine in their drinking water at unannounced visits. 13 Rates of use will need to be improved considerably if point-of-use water treatment approaches are to contribute substantially to meeting the millennium development goals. The Procter & Gamble Company developed a combined flocculant-disinfectant for household water treatment in low- income communities. The flocculant-disinfectant is packaged in sachets designed to treat 10 L of contaminated water. The water treatment process combines precipitation, coagulation, and flocculation with chlorination. It aggregates and facili- tates the removal of suspended organic matter, bacteria, vi- ruses, parasites, and heavy metals in treated water. 14 Two health outcome efficacy studies of the flocculant-disinfectant were conducted in Guatemala between 2001 and 2003. The first study found that children living in households that were randomly assigned to receive the flocculant-disinfectant had 25–29% fewer days of diarrhea, although use of the product was suboptimal. 15 The second study tested a modified form of the flocculant-disinfectant with a lower dose of chlorine to improve taste, and used village women to actively encourage use. Households receiving the intervention reported 39% fewer days of diarrhea than control households. 16 Three weeks after the second health outcome efficacy study was complete, national marketing of the flocculant- disinfectant was extended into the region where the efficacy studies had been conducted. We returned to the study popu- lation 6 months later to assess purchase and use of the floc- culant-disinfectant and to identify characteristics associated with purchase and use of the flocculant-disinfectant after the product was no longer provided free of cost to participants. * Address correspondence to Stephen P. Luby, ICDDR, B GPO Box 128, Dhaka 1000, Bangladesh. E-mail: sluby@cdc.gov Am. J. Trop. Med. Hyg., 78(3), 2008, pp. 382–387 Copyright © 2008 by The American Society of Tropical Medicine and Hygiene 382