INFORMATION FOR ACTION FROM THE WATER AND SANITATION FOR HEALTH PROJECT

Household Water Disinfection in Prevention 254.0 93HO

1. Introduction productivity as well. Anecdotal evidence of a significant connection between household disinfection and diarrhea In January 1991, cholera appeared in Peru after an absence morbidity is being gathered in Guatemala, where health of- of nearly 100 years and spread rapidly throughout Latin ficers observed a significant decline in diarrheal illness America and the Caribbean, creating a public health emer- and death during a recent hygiene education campaign di- gency. One very effective emergency measure, household rected against cholera. As the disease receded, however, disinfection of water, is the subject of this technical note, the motivation to continue disinfection dropped and diar- .J written primarily for U. S. Agency for International Devel- rhea returned to previous levels. opment (A.I.D.) health officers and appropriate national health personnel in countries where cholera is endemic or epidemic or other waterbome diseases are prevalent. ' 2. Last Line of Defense: Household disinfection of water can make a significant Household Disinfection contribution to protecting people in situations where water supplies are contaminated. When the supply of water to a community is found to be Household disinfection outreach and extension cam- unsafe, it may not be possible to make it safe in the short paigns must instruct people in threatened communities in term. If cholera is present, disinfection at the household how to disinfect their household water and motivate them level—the last line of defense—may be appropriate. to do so. National-level commitment is crucial for such Disinfecting water kills or inactivates most patho- campaigns to be effective. Recent experience in Peru pro- genic organisms, including those that cause cholera. Un- vides an example of how a national policy for household like sterilization, disinfection does not kill all living disinfection may be established and successfully im- micro-organisms, but should kill those causing disease. plemented. Following the outbreak of cholera in early Those that are -resistant may be bacterial 1991, Peru's Ministry of Health made a policy at the na- spores, bacteria in clumps, fungi, protozoan cysts, and par- tional level to distribute disinfection packets for disinfect- asite eggs and worms (some may be pathogenic) that re- ing water in the home. Collaboration was enlisted with the quire additional treatment, such as filtration, to be Ministry of Housing and Construction, and the Pan Ameri- removed from water. can Center for Sanitary Engineering and Environmental Chemical measures of disinfection include treatment Science (CEPIS), located in Lima. Technical assistance with or iodine, while physical measures include was extended to regional and local government agencies boiling and ultraviolet radiation, the latter not a method to organize cholera committees through community health suitable for household use. Filtration, while not a method centers. These committees distributed the disinfection ma- of disinfection, can improve water quality. terials to households and also provided demonstrations on By far the most common chemicals used for water dis- how to purify water in the home. infection are chlorine and iodine. While chlorine is not To be successful, household-level prevention efforts must be part of a comprehensive "package" of anti-cholera interventions, such as programs and policies that encour- age oral rehydration therapy, breastfeeding of infants, safe and sanitary excreta disposal, personal and household hy- giene, and disinfection of drinking water. National-level support for education and training programs at the commu- 1611 N. Kent Street, Room 1001 nity and individual levels is also essential. Arlington, Virginia 22209-2111 USA There are more than 20 serious waterbome diseases in TEL: (703) 243-8200 FAX: (703) 243-9004 addition to cholera. And while their impact on the mortal- Sponsored by: ity of infants and small children is most visible, they un- U.S. Agency for International Development dermine families' overall well-being and adult Operated by: CDM and Associates without its risks, it is the most widely available, most cost Cholera: Facts and Figures effective and best understood chemical used for the disin- fection of drinking water. Iodine, on the other hand, has Cholera is an acute enteric bacterial infection that not been used much because of cost, limited availability, strikes quickly and can kill within hours if untreated. It is and more important, potential side effects when used for produced by ingesting an infectious dose of the disease- long periods. Chlorine owes its wide availability to its use causing agent, Vibrio cholerae 01 (an infectious dose of in large-scale water treatment facilities and in the produc- 100 million vibrios may be contained in 1 cubic centime- ter of a cholera patient's stool). Cholera produces pro- tion of a variety of household cleaning and washing mate- fuse watery stools, vomiting, rapid dehydration, acidosis rials. When properly applied to water disinfection, (increased acidity of the blood and tissues), and collapse chlorine does not have adverse health effects and is very of the circulatory system. The vibrios are shed via the effective for controlling acute gastrointestinal diseases stools into the environment during the acute phase and caused by bacteria and viruses. for a few days after recovery, where they continue to Boiling is also a very effective means of disinfection, spread rapidly by the fecal-oral route. They are shed not and often the order to boil water is issued by government only by the obviously sick but by many people with either health officials when cholera first appears. Boiling is often mild symptoms or no symptoms at all. The onset of chol- too expensive and impractical, however, as seen below. era occurs after an incubation period of two to three The amount of clean water per person that is required days; the disease may last from one to six days. Suscep- tibility and resistance are variable, but most clinical cases to maintain good hygiene is about 20-30 liters a day; a are observed in the lowest socio-economic groups where minimum of two liters is needed to sustain life. In situa- safe water and sanitation are often unavailable and tions where it is difficult to disinfect enough water for where sanitation practices are often poor. Antibodies are drinking and cooking, as well as for washing hands and all devebped by early adulthood in endemic areas. surfaces coming into contact with food, nondisinfected In severe cases, rapid dehydration and loss of water can be used for bathing or washing laundry so long electrolytes can lead to death. Cholera victims can be as people are careful not to get the water in their mouths. successfully treated by oral administration of a glu- cose-electrolyte solution. Oral rehydration salts (ORS) Chlorination are widely available and frequently recommended. Chlorinaa'on is the most common disinfection method be- Commonly, only the cases that have been allowed to progress to severe dehydration, shock, and/or uncon- cause it is cheap, reliable, and widely available in several sciousness will require intravenous rehydration. Antibi- forms. In adequate amounts chlorine kills or inactivates otic treatment is not considered essential to recovery cholera vibrios and other pathogens in 30 minutes. but is thought to shorten the duration of diarrhea, thus Chlorine products. Three chlorine products suitable reducing the adverse effects on the patient and the for household disinfection are widely used: sodium hypo- volume of vibrio-contaminated excreta. chlorite solution (liquid ); chlorinated lime (bleach- Cholera is considered pre-eminently a waterborne ing powder); and calcium hypochlorite (used in swimming disease. Cholera vibrios persist in salt water or contami- pools). Some manufacturers of swimming pool hypochlo- nated ice. In the recent Peruvian epidemic, municipal rite and liquid add stabilizers that may be toxic; drinking water that was inconsistently disinfected was found to be a major path by which the disease traveled. however, solutions will be marked accordingly. In addition, food, especially that sold by street vendors, Naturally, whichever product is recommended must can be a vehicle for cholera, although the food is usually be available locally. solution, or contaminated by unsafe water. Transmission through di- rect contact with infected persons and indirect transmis- Table 1 sion through locally grown vegetables and fruits and Survival of Vibrio Cholerae in Water seafood eaten raw can also occur. Any mechanism that allows fecal material to enter into the digestive tract of Type of Water Temperature Survival Time the host will transmit cholera. V/brio cholerae 01 is killed or inactivated by expo- Clean (dechlorinated sure to low pH (<4.0), heat, and several disinfectants. tap water) 4°C 1 month Drying can also destroy it, but this is not a practical 20-30° C 2-14 days control measure. Vibrio choleras can survive a month Untreated fresh 4°C 1 + month or more in fresh water at 4° C, and twice that long in seawater at the same temperature, as shown in 20-30° C 1-20 days Table 1. Increasing the temperature shortens the sur- Seawater 4°C 2 months vival time, so that boiling water for one minute at sea 20-30° C 6-60 days level or three minutes at higher elevations will inacti- Source: Feachem, 1983. vate or kill the cholera organisms. liquid bleach, is sold in most markets the world over, is rel- Table 2 atively inexpensive, and is much more readily available than powdered (or pellet materials). Chlorinated lime and Usa of Liquid Bleach calcium hypochlorite are also widely available and are not (5.25% Sodium Hypochlorite) for Water Disinfection costly. Each of these products yields a different amount of chlorine, so instructions for use as a drinking water disin- Amount of Bleach to Add Volume fectant vary. It is therefore advisable that local health au- of Water To provide 1 mg/l (1 ppm) To provide 10 mg/l (10 ppm) thorities check out the availability of chlorine products (In liters) of available chlorine oí available chlorine and their chlorine content. Decisions about which products 1 2 3 1 2D /4D 4D to use in a household disinfection campaign can be made 1 2 3 with some efficiency once this information is known. It 5 3D /6D 1.5 ml 1 2 3 should also be noted that chlorine products, once opened, 10 6D /12D 3 ml lose their strength over time. 50 1 ml 10 ml

The problem of turbidity. Visibly cloudy water indi- 100 2 ml 20 ml f cates the possible presence of a greater number of bacteria 500 10 ml 100 ml than would be found in clear water. Cloudiness may be 1000 20 ml 200 ml due to suspended inorganic or organic matter, or both. D = Drop {with eyedropper) = .05 ml •*• Since chlorine reacts readily with any organic matter, 1. Dosages slightly higher than 1 mg/l for ease in measuring. cloudy or muddy water will consume more chlorine than 2. For clear water. clear water. Hence the World Health Organization advo- cates either boiling turbid water or filtering it before chlori- 3. For cloudy water. nation. If filtering is not possible, allowing the suspended Source: Adapted from the Clorox Company. matter to settle will clarify the water. Alternatively, it is possible to increase the chlorine Use of liquid bleach. The easiest method of chlorinat- concentration applied to meet the high demand for chlo- ing household water is to apply liquid bleach (5.25% so- rine caused by the turbid water. This is done by adding an dium hypochlorite) directly according to the increased amount of chlorine until the odor of chlorine is recommended dosages presented in Table 2. Typically, in evident even after the treated water has been allowed to sanitary engineering practice, disinfected water should stand for 30 minutes. This assures that the concentration maintain at least 1 milligram per liter (1 mg/l) of chlorine of chlorine is adequate both to satisfy the demand of the residual, equivalent to 1 part per million (ppm). The appli- turbidity and to provide excess chlorine for disinfection. cation of 1 ppm (1 mg/l) of liquid bleach to clear water is Dosages should be adjusted downward until the odor and sufficient for disinfection. The concentration should be taste are less noticeable. doubled for water that has some turbidity. Table 2 presents application rates for 1 ppm (1 mg/l) Methods of chlorination. There are two ways to chlori- and 10 ppm (10 mg/l) of available chlorine (the amount of nate water using readily available materials. No matter chlorine present in a product). The 1 ppm rate is normally which of the methods is used, certain principles should be sufficient for clear water, and thus is appropriate for house- observed. After the disinfectant has been added to the water, always let it stand for a minimum of 30 minutes. holds in most marginal urban areas and in larger rural com- Even a slight odor of chlorine after this amount of time munities. These people are likely to obtain their water will confirm that the water is safe to drink. The odor indi- either from distribution systems that are plagued with inter- cates that there is a residual of chlorine in the water, mittent supply problems or from vendors. Both require which assures its safety. As with many processes, the ef- families to store water in the home. In most cases this fectiveness of chlorine in disinfecting water decreases water is clear, but if it is slightly cloudy, then the applica- with lowered temperatures. Therefore, in a cold climate it tion rate should be doubled to ensure that a safe residual is is advisable to allow a longer waiting time after chlorine maintained. However, in those instances where people liv- is added. Recontamination can easily occur, for example ing in congested areas draw water directly from a river or by putting dirty hands into the water container. There- a stream, the 10 ppm (10 mg/l) application rate is advis- fore, a clean jar with a spigot should be used for storage. able. Water from surface sources will likely be turbid and Otherwise, water must be poured off the top, not ladled highly contaminated with fecal matter. out. Finally, because it is so easy to contaminate drinking Liquid bleach is plentiful and cheap. For example, on water—a minute number of organisms can multiply over- average it costs about U.S.$0.65 per liter in Latin Amer- night into an infective dose—the World Health Organiza- ica. A family of six living in a marginal urban area would tion recommends disinfecting only the,#niount( needed,, not have to spend "very flinch to disinfect enough water to for a 24-hour period. j CL^Th, maintain hygiene. &- household of six consuming water at

P.O. Box 93190. '?b0% AD The Ha Tel. (070) 8:491! ex. 141/142 the rate of 20 liters per person per day would need to disin- distribution of packets of chlorine materials. Or a decision fect 3600 liters per month (43,200 liters per year). Applied may be made to use pre-packaged materials because there at the rate of 1 ppm, 900 milliliters (ml) of liquid bleach is less guesswork connected with their use, and distribut- would be required to disinfect 43,200 liters of contami- ing them free may yield public health benefits. nated water, if it is not turbid. Thus, a one-liter bottle of The product could be packaged in amounts sufficient liquid bleach would be sufficient to disinfect water in the to make one liter of a one-percent stock solution: 200- average household for one year. (However, since chlorine gram packets of 5 percent available chlorine bleaching dissipates over time once the container is opened, conserv- power, for example, or HTH (high-test hypochlorite) tab- ing the same bottle for the entire year is not advisable. A lets. Figure 1 shows the kind of instructions that were household should contemplate buying liquid bleach in given by the government of Peru in a household disinfec- smaller quantities and more frequently to assure potency.) tion campaign using HTH tablets. Where people are taking water from rivers or streams, Pros and cons of chlorination. Chlorination is gener- an urban family living in a marginal area using about ally the cheapest safe method of disinfection. The materi- 43,200 liters per year would need nine liters of liquid als required are widely available and it is a relatively easy bleach at a total cost of about U.S.$6.00—not a prohibi- process. Because it contains residual disinfectant, chlori- tive sum. nated water can be transferred from one container to an- Use of a stock solution. The second way to chlorinate other without risk of recontamination. household water is to make a stock solution (chlorine di- As for drawbacks, any undiluted chlorine product is luted with water) and use it to disinfect water. Table 3 pres- potentially harmful to children, either through skin contact ents how a one-percent stock solution can be made from or ingestión. Hence the product, as well as the stock solu- other materials containing chlorine. The application of a tion, should be stored out of their reach. Likewise, getting one-percent solution is presented in Table 4. Application the dosage right could present problems in some settings. rates for a one-percent stock solution are given for 1 ppm If too little chlorine is added, the water still may not be and 10 ppm respectively. Clear water would be treated with safe. Also, chlorinated water has a definite taste and odor the 1 ppm rate, the rate would be doubled for cloudy water that people may find objectionable. with some turbidity, and the 10 ppm rate would be applied Chlorination has been found to produce trihalometh- if water was being taken from streams or rivers. ane (THM) compounds. The formation of these com- A one-percent stock solution can be prepared by fill- pounds is a function of concentration, contact time, ing a clean one-liter bottle with clear water and adding the chlorine dose, and pH. One of the THMs, chloroform, is a recommended amount of bleaching powder, liquid bleach, potential human carcinogen. However, since the mean age or calcium hypochlorite. The bottle should then be cov- at death for those who die of cancer is 67 years, it is not ered and shaken. Stored in a dark place, it should provide sensible to argue that it is better to risk death in childhood a reliable disinfectant for at least 30 days. or as a young adult from cholera or another waterborne Prepackaging and distribution. In the event that prod- disease, than to risk death at 70 from cancer. ucts to use directly for disinfection, such as liquid bleach, or to use to make a disinfectant solution, such as bleaching Table 4 powder, are not readily available on the local market, it Use of One-Percent Chlorine Solution may be necessary for policymakers to include in then- for Water Disinfection household disinfection program the prepackaging and Amount of Solution to A dd Volume Of Water To provide 1 mg/l (1 ppm) To provide 10 mg/l (10 ppm) Table 3 (in liters) of available chlorine of available chlorine

Making a One-Percent Stock Solution 1 10D720D2 5 ml Product (% concentration by 5 2.5ml1/5 ml2 25 ml weight of available chlorine) Amount per liter of water 1 2 10 5ml /10ml 50 ml Sodium hypochlorite 50 25 ml 250 ml (liquid bleach, 5%) 200 ml 100 50 ml 500 ml Sodium hypochlorite (10%) 100 ml 500 250 ml 2.5 I Chlorinated lime 1000 500 ml 51 (bleaching powder, 5%) 200 g D * Drop (with eyedropper) = .05 ml Calcium hypochlorite (HTH, high-test hypochlorite 1. Clear water. powder, 70%) 14 g 2. Cloudy water. r v

Jipi*-"' "" 'IfPP "'

figuro 1. Instructions for making and using a chlorine stock solution contained in a publication of the Government of Peru: "Desinfección del Agua para Usos Domiciliarlos y Centros Comunales."

Boiling 3. Disinfection Systems Not Proven Boiling is the simplest disinfection method so long as fuel Effective Against Cholera is readily available. Unfortunately, fuel is scarce and ex- pensive in many developing countries. However, boiling can serve as an important line of defense in the short term, Some disinfection systems destroy many bacteria but particularly in an emergency situation where chlorine and are of unproven effectiveness when it comes to cholera. the skill to use it have not yet been acquired. Solar disinfection, for example, has aroused consider- Water need only be boiled vigorously for two minutes able interest, and many community-level health or ap- in order to be safe for drinking. According to conventional propriate technology manuals give instructions for its wisdom, the duration of boiling is to be increased for alti- use. The use of the sun alone in certain situations can tude adding one minute for each thousand meters above provide substantial improvement in water quality. With sea level. However, just bringing water to a boil at any alti- nothing more than a glass jar or polyethylene bag, it is tude is sufficient to kill cholera vibrios. A good rule of possible to destroy many bacteria. Unfortunately, how- thumb is to boil water everywhere for two minutes to be ever, solar disinfection has so far not been found to kill safe, and for added safety for five minutes at 9000 meters the cholera vibrio. or higher altitude. Other disinfection methods have also been devel- Since boiled water is easily recontaminated, transfer- oped, but none is effective against cholera. Chlorine ring it from the boiling pot to another container is strongly disinfection and boiling are the only practical meth- discouraged. This could be a problem in households that ods suitable for household use when cholera is may need all their vessels for cooking. present.

:'•<«!**••• 4. Filtration To Improve Water Quality

Filtration of water can greatly reduce pathogen counts and increase water quality, but it cannot remove 100 percent of organisms and therefore does not provide pro- tection against cholera. Where filtration is useful is in metal container reducing turbidity. Because the particles that cause turbidity harbor organisms, filtering reduces chlorine demand. Slow-sand filter technology, which provides drinking water treatment for many communities in both developed and developing countries, can be adapted to household use in the form of a packed-drum filter (see Figure 2). Like a larger-scale slow-sand filter, the packed-drum filter im- proves water quality in two ways. First, it decreases turbid- ity. Second, a properly constructed sand filter will have a biological mat on the surface that is composed of algae, Figuro 2. The packed-drum filter is not a simple technology. plankton, bacteria, and other life forms. This active layer traps bacteria, viruses, spores, and protozoan cysts. How- 5. Health-Enhancing Support Systems ever, the layer may not be 100 percent effective, allowing enough organisms to penetrate the filter medium to cause Household disinfection will not be effective unless it is disease in those who drink the water. Therefore, the adap- supported by health-enhancing practices. tation of this slow-sand filter technology to households is not recommended. Handwashing In addition to the risk of not providing complete effec- tiveness in trapping bacteria, maintaining the integrity of Good personal hygiene is critical. The importance of wash- the filter presents technical challenges well beyond the ca- ing with soap or ash and decontaminated water after any pability of the average household, especially in marginal contact with feces and before eating needs to be impressed upon everyone. Whoever handles food in the household urban areas. For example, the packed-drum filter must be should exercise special care. This means washing before properly packed with appropriate sized sand and stones, preparing or serving food. In addition, hands must be and, once put in use, must be maintained wet with water washed after handling raw food or anything else that covering the biological mat at all times. The water cannot might be contaminated. be allowed to flow too fast through the filter. And the bio- logical mat must be cleaned out routinely and a new layer of disinfected sand put in, along with a small portion of Proper Storage and Handling of Water the original biological mat to encourage regeneration of Disinfected water (as well as disinfection solution) should the mat over the new sand. In short, the packed-drum tech- be covered and stored in a dark place because sunlight and nology requires considerable training and a sustained ef- air hasten the deterioration of chlorine. Storage containers fort to manage the unit. should be cleaned once a month with a chlorine solution. If there is any possibility that the disinfected water has Filtering for clarifying water only. A sand filter may been recontaminated by coming into contact with a dirty be used only to clarify the water and not to remove bacte- cup or utensil or a dirty hand, it should be discarded and ria. In that case, the design is simpler and operation and the container should be thoroughly washed. maintenance are less demanding. For simple filtration, it is The slightest contact with a contaminated surface can not necessary to keep the sand layer submerged. To filter introduce pathogens to water and lead to recontamination. the water, the cover of the packed-drum is removed and It is important, therefore, that the storage container be de- the desired quantity of water is simply poured into the signed to prevent contact between water and hands or filter. water and utensils. In South Africa, investigators found Pros and cons of filtering. If the materials are ready at that Vibrio cholerae survived for as long as 7 days in hand, filtering is a relatively easy and inexpensive way of clay pots used as household water containers, 17 days in improving water quality. However, in situations where plastic water containers, and 27 days in water containers cholera is present, filtering can only be relied on to elimi- made from iron drums (Patel 1989). By contrast, in Cal- nate turbidity, not to protect against infection. The water cutta, an intervention trial that provided treatment families must be disinfected after filtering. with narrow-necked water pitchers (into which hands Table 5 Survival of Cholera In Food and Drink

Period of Survival Specimen at20-2FC

Ground coffee 1 hour Lime, lemon 1 hour Papaya 5 days Tomatoes, figs, raisins 1 day Celery, green beans, bean sprouts S days Nuts and wheat 3 days Coca-cola 1day Rose water 2 days Tea leaves 1 day Figure 3. This household water storage container meets all of Fish and shellfish (refrigerated) 1-2 weeks PAHQs criteria. Cooked rice, tapioca, eggplant - —- 1-2 weeks could not be introduced) was associated with a significant de- Milk desserts 1-2 days crease in cholera, compared with control families (Deb 1982). Source: Feacham, 1983. The Pan American Health Organization (PAHO) has de- veloped several criteria for judging the suitability of house- drugstores carry Lugol's solution. The water hold water containers (Witt and Reiff 1992) as follows. should be discarded after use. A good water container should... • Fish and shellfish are often contaminated and • be appropriate in size (10 to 20 liters) and have a should be washed and cooked. handle for easy transport and a stable base • Food must be cooked thoroughly and then eaten • be made of a durable, translucent, lightweight non- promptly. oxidizing material resistant to breakage (such as • If foods are to be stored for more than four or five high density polyethylene) hours, they should be refrigerated or kept in an ice • have a mouth that makes it easy to fill the con- box below 10° C. Or they can be kept in a hot box tainer and add the disinfectant but difficult (or im- above 60° C. Food prepared for infants should not possible) to immerse ladles or other utensils; be stored at all. • be equipped with a non-rusting, durable, easy-to- • All cooking and serving utensils, cutting boards, or clean spigot for extracting water tables used for preparing food must be washed and • have a strong serviceable cover connected to the air dried after use. These may also be soaked in container so that it will not get lost or dirty Lugol's solution mixed in the proportion for food • allow air to enter as water is extracted disinfection given above. • be imprinted or labeled with clear instructions for • Even slight indirect contact with raw food— its sanitary use and maintenance. through a knife or cutting board, for example—can To ensure that the container meets these criteria, it should contaminate properly cooked food. Persons who be approved by the local sanitary authorities. Figure 3 de- touch raw food should wash their hands afterward. picts a container that meets these criteria. • Canned, dried, and acidic foods are generally safe to eat in areas where cholera is present. Most fruits Proper Handling of Food that taste slightly sour have a pH safely below 4.5 Since cholera can be transmitted through food, proper han- and are not receptive to the cholera organism. Still, dling and preparation of food is essential. their skins need to be cleaned and peeled. Olive • Raw food other than whole fruits and vegetables oil, fish oil, cocoa butter, and olives are unlikely to that can be peeled should be avoided. However, contain cholera vibrios. Table 5 shows the survival fruits and vegetables can be scrubbed with soapy time of cholera in some common foods and drinks. water, rinsed and then soaked in a solution made from tincture of iodine (Lugol's solution) for 15 Water Testing minutes. Five ml of Lugol's solution per liter of In many households, testing the water supply to be sure it water will be adequate for food disinfection. Most is disinfected is impractical. However, an odor of chlorine guarantees the presence of residual disinfectant. If a chlo- Some educational campaigns might also run counter to cul- rine test kit is available, a reading can be taken after 30 tural practices that are not hygienic, such as sharing food and minutes of contact. If the test shows at least 0.5 parts per drink from a common vessel or eating uncooked seafood. In million residual (0.5 mg/l), the water is safe to drink. some West African countries, for example, it is customary The simplest test kit employs the property of DPD for the same women who prepare the body of a cholera vic- (Diethyl-para-phenylene diamine) to turn pink in the pres- tim for burial to cook the food for the funeral feast. This prac- ence of chlorine in water. A sample of treated water is tice has been shown to contribute to the spread of cholera. placed in a 10 ml tube. A tablet of DPD is added. The tab- The most successful informational campaigns are let quickly dissolves and the color is read immediately. built on firmly held ideals or beliefs. For example, CEPIS in Lima, Peru, designed a kit for home use that Muslims perform ritual ablutions before prayer and value costs about U.S. $1.00. This kit is manufactured in Lima ritual cleanliness. In Muslim communities, informational by Ing. Isaac Lavado, tel. (5114) 28-2322 or 27-3809. campaigns about safe hygiene practices can refer to these ATEIN S.A. in Alajuela, Costa Rica, manufactures the beliefs and attempt to extend and amplify the practices. Clorotest (60 tests for $2.50 per unit) tel. (506) 37-3054, fax. (506) 41-0107. The HACH Company in Loveland, * * * * Colorado, U.S .A., tel. (303) 669-3050, also manufactures While a household disinfection program can be very effec- simple tests kits that use the DPD process. tive in retarding the spread of cholera and other water- borne diseases, it should be viewed as an emergency or temporary measure, not as an alternative to working stead- 6. Educational Campaigns ily toward providing safe water and sanitation for all.

Educational campaigns are vital, but before they can be designed and organized, background assessments of the Sources of Additional Information beliefs and behaviors of the target audience need to be carried out. Similarly, information on who does what in Deb, B. C. et al. 1982. "Jntra-familial Transmission of Vibrio the household must be available so that the informational Cholerae Biotype El Tor in Calcutta Slums," Indian Journal of Medical Research 76:814-819. campaign is aimed at the right persons. Feacham, Richard G., David J. Bradley, Hemda Garelick, and D. Household disinfection programs must target persons Duncan Mara. 1983. Sanitation and Disease, Health Aspects of responsible for household water. For example, the disin- Excreta and Wastewater Management. Published for the World fecting materials, the measuring implements and storage Bank by John Wiley & Sons, New York. Pan American Health Organization. 1991. Risks ofTransmisshn vessels used in the promotional campaign must be appro- of Cholera by Foods. Washington, DC. priate for the audience. In the Peru campaign mentioned Pan American Health Organization. 1991. "Special Report: Chol- earlier, a teacup, a beer bottle and a teaspoon were chosen era. Cholera in the Americas." PAHO Bulletin Vol. 25, No. 3. as measuring implements and the written instructions for Patel, M., and M. Isaccson. 1989. "Survival of Vibrio Cholerae in African Domestic Water Storage Containers," South African household disinfection were accompanied by pictures that Medical Journal 76:365-367. also carried the message. This seemingly self-evident pre- Ross Institute. 1987. Small Water Supplies. The Ross Institute cept is not always followed. Bulletin: Information and Advisory Service. Bulletin No. 10. Also, effective ways must be found to reach the target Sandy Cairncross and Richard Feachem. United States, Department of State. January, 1992. Food Service audience. In some contexts, for example, instructional leaf- Sanitation Guide. Washington, DC. lets might not be appropriate; community demonstrations Volunteers in Technical Assistance. 1985. Understanding Water may be called for. These might be channeled through local Supply and Treatment for Individual and Small Community or community-based organizations, such as government- Systems. Arlington, VA. sponsored community health groups, church organiza- Water and Sanitation for Health Project. May 1992. "Cholera Pre- vention and Control." Fact Sheet. Arlington, V A. tions, civic clubs, or any other association with strong ties Water and Sanitation for Health Project. March 1992. "Disinfec- to the people it works with. Mass media announcements tion for Rural Community Water Supply Systems in Develop- can serve to reinforce the grassroots efforts, if they are tar- ing Countries." Technical Note. Arlington, VA. geted carefully. Mistakes can be made. One country broad- Witt, Vicente M., and Fred M. Reiff. 1992. "Estrategias Al- ternativas para la Desinfección del Agua Aplicable a Zones Ur- cast health messages on the national radio station, but the banas Marginales y Rurales." Pan American Health targeted audience had come from a neighboring country Organization. and listened only to its broadcasts. World Health Organization. 1971. Guide to Sanitation inNatural Disasters. M. Assr, M.S.S.E., Under-Secretary of State for Plan- Misconceptions about cholera and disease in general ning and Programs, Ministry of Health, Teheran, Iran. abound, such as the belief that infant feces are harmless. World Health Organization. 1992. Guidelines for Cholera Con- These must be addressed in an educational campaign. trol. Geneva, Switzerland.