Interventions to improve excreta disposal for preventing diarrhoea

Abstract

BackgroundDiarrhoeal diseases are a leading cause of mortality and morbidity, especially among young children in low-income countries, and are associated with exposure to human excreta. ObjectivesTo assess the effectiveness of interventions to improve the disposal of human excreta for preventing diarrhoeal diseases. Search methodsWe searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CEN-TRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; the metaRegister of Controlled Trials (mRCT); and Chinese-language databases available under the Wan Fang portal, and the China National Knowledge Infrastructure (CNKI-CAJ). We also handsearched relevant conference proceedings, and contacted researchers and organizations working in the field, as well as checking references from identified studies. Selection criteriaRandomized, quasi-randomized, and non-randomized controlled trials (RCTs) were selected, comparing interventions aimed at improving the disposal of human excreta to reduce direct or indirect human contact with no such intervention. Cluster (eg at the level of household or community) controlled trials were included. Data collection and analysisWe determined study eligibility, extracted data, and assessed methodological quality in accordance with the methods prescribed by the protocol. We described the results and summarized the information in tables. Due to substantial heterogeneity among the studies in terms of study design and type of intervention, no pooled effects were calculated. 1 Interventions to improve disposal of human excreta for preventing diarrhoea (Review)

Water, sanitation and hygiene for the prevention of diarrhoea

“…Our initial attempt at this review nearly foundered. The initial search 13 produced seven quasi-randomized intervention studies with diarrhoea morbidity as the outcome measure, and one with diarrhoea mortality ( Figure 5 , Table 4 ). The mortality study has already been mentioned; 23 the intervention included water supply and education about oral rehydration therapy, which could explain the observed reduction in mortality.…”

“…), of the intervention (is sewerage in Brazil different from pit latrines in Africa? ), on the range of languages accepted (in several recent reviews, 13 , 45 more than a third of useful studies were in Chinese) and on which are regarded as the gravest methodological deficiencies. Each of those questions has more than one reasonable answer.…”

“…Again we followed the Cochrane approved protocol 13 to search for interventions to dispose of human excreta so as to reduce direct or indirect human contact. This includes any steps to remove or contain faeces, such as simple pit latrines, bucket latrines, hanging toilets and composting toilets, and should be contrasted with open defecation.…”

“… Quality assessment No of events Effect Design Limitations Consistency (based on the heterogeneity of the meta) Generalizability to population of interest Generalizability of intervention Intervention Control RR (95% CI) Outcome 1: Diarrhoeal mortality for all ages; Quality: very low 2 8 , 27 RCT and quasi-RCT No placebo, not blinded, one randomized, self-reported and self-defined diarrhoea (−1.5) NA Both Africa, 1 is all ages, 1 under 5s (−0.5) 1 all-cause mortality, 1 diarrhoeal mortality 34 55 Ranging from 0.61 to 0.15 a Outcome 2: Diarrhoeal morbidity for all ages; Quality: very low 38 (30 studies, 5 with multiple arms; arms counted as additional trials) 1–30 RCT and quasi-RCT Only three blinded and placebo, few adequately randomized, most self-reported diarrhoea with excessive recall period. (−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 …”

“…(−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 45 098 0.54 (0.38–0.88) c 4 1 , 5 , 12 Double blind studies Inadequate randomization, high loss to follow-up, coverage not measured (−0.5) Heterogeneity not significant ( P = 0.30) 1 Lat Am, 1 Africa, 1 USA, all ages (−0.5) Moderate and severe morbidity (−0.5) 1912 1987 0.93 (0.70–1.33) c 11 20–30 Quasi-RCT Inadequately randomized, no placebo, mostly self-reported with excessive recall period (−2) Significant heterogeneity (−0.5) Mostly Asia and Africa, all ages (−0.5) Moderate and severe morbidity (−0.5) 18 334 b 19 125 b 0.62 (0.48–0.89) c 6 20 , 21 , 23 , 24 , 27 , …”

Water, sanitation and hygiene for the prevention of diarrhoea

“…Our initial attempt at this review nearly foundered. The initial search 13 produced seven quasi-randomized intervention studies with diarrhoea morbidity as the outcome measure, and one with diarrhoea mortality ( Figure 5 , Table 4 ). The mortality study has already been mentioned; 23 the intervention included water supply and education about oral rehydration therapy, which could explain the observed reduction in mortality.…”

“…), of the intervention (is sewerage in Brazil different from pit latrines in Africa? ), on the range of languages accepted (in several recent reviews, 13 , 45 more than a third of useful studies were in Chinese) and on which are regarded as the gravest methodological deficiencies. Each of those questions has more than one reasonable answer.…”

“…Again we followed the Cochrane approved protocol 13 to search for interventions to dispose of human excreta so as to reduce direct or indirect human contact. This includes any steps to remove or contain faeces, such as simple pit latrines, bucket latrines, hanging toilets and composting toilets, and should be contrasted with open defecation.…”

“… Quality assessment No of events Effect Design Limitations Consistency (based on the heterogeneity of the meta) Generalizability to population of interest Generalizability of intervention Intervention Control RR (95% CI) Outcome 1: Diarrhoeal mortality for all ages; Quality: very low 2 8 , 27 RCT and quasi-RCT No placebo, not blinded, one randomized, self-reported and self-defined diarrhoea (−1.5) NA Both Africa, 1 is all ages, 1 under 5s (−0.5) 1 all-cause mortality, 1 diarrhoeal mortality 34 55 Ranging from 0.61 to 0.15 a Outcome 2: Diarrhoeal morbidity for all ages; Quality: very low 38 (30 studies, 5 with multiple arms; arms counted as additional trials) 1–30 RCT and quasi-RCT Only three blinded and placebo, few adequately randomized, most self-reported diarrhoea with excessive recall period. (−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 …”

“…(−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 45 098 0.54 (0.38–0.88) c 4 1 , 5 , 12 Double blind studies Inadequate randomization, high loss to follow-up, coverage not measured (−0.5) Heterogeneity not significant ( P = 0.30) 1 Lat Am, 1 Africa, 1 USA, all ages (−0.5) Moderate and severe morbidity (−0.5) 1912 1987 0.93 (0.70–1.33) c 11 20–30 Quasi-RCT Inadequately randomized, no placebo, mostly self-reported with excessive recall period (−2) Significant heterogeneity (−0.5) Mostly Asia and Africa, all ages (−0.5) Moderate and severe morbidity (−0.5) 18 334 b 19 125 b 0.62 (0.48–0.89) c 6 20 , 21 , 23 , 24 , 27 , …”

Water, sanitation and hygiene for the prevention of diarrhoea

“…Our initial attempt at this review nearly foundered. The initial search 13 produced seven quasi-randomized intervention studies with diarrhoea morbidity as the outcome measure, and one with diarrhoea mortality ( Figure 5 , Table 4 ). The mortality study has already been mentioned; 23 the intervention included water supply and education about oral rehydration therapy, which could explain the observed reduction in mortality.…”

“…), of the intervention (is sewerage in Brazil different from pit latrines in Africa? ), on the range of languages accepted (in several recent reviews, 13 , 45 more than a third of useful studies were in Chinese) and on which are regarded as the gravest methodological deficiencies. Each of those questions has more than one reasonable answer.…”

“…Again we followed the Cochrane approved protocol 13 to search for interventions to dispose of human excreta so as to reduce direct or indirect human contact. This includes any steps to remove or contain faeces, such as simple pit latrines, bucket latrines, hanging toilets and composting toilets, and should be contrasted with open defecation.…”

“… Quality assessment No of events Effect Design Limitations Consistency (based on the heterogeneity of the meta) Generalizability to population of interest Generalizability of intervention Intervention Control RR (95% CI) Outcome 1: Diarrhoeal mortality for all ages; Quality: very low 2 8 , 27 RCT and quasi-RCT No placebo, not blinded, one randomized, self-reported and self-defined diarrhoea (−1.5) NA Both Africa, 1 is all ages, 1 under 5s (−0.5) 1 all-cause mortality, 1 diarrhoeal mortality 34 55 Ranging from 0.61 to 0.15 a Outcome 2: Diarrhoeal morbidity for all ages; Quality: very low 38 (30 studies, 5 with multiple arms; arms counted as additional trials) 1–30 RCT and quasi-RCT Only three blinded and placebo, few adequately randomized, most self-reported diarrhoea with excessive recall period. (−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 …”

“…(−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 45 098 0.54 (0.38–0.88) c 4 1 , 5 , 12 Double blind studies Inadequate randomization, high loss to follow-up, coverage not measured (−0.5) Heterogeneity not significant ( P = 0.30) 1 Lat Am, 1 Africa, 1 USA, all ages (−0.5) Moderate and severe morbidity (−0.5) 1912 1987 0.93 (0.70–1.33) c 11 20–30 Quasi-RCT Inadequately randomized, no placebo, mostly self-reported with excessive recall period (−2) Significant heterogeneity (−0.5) Mostly Asia and Africa, all ages (−0.5) Moderate and severe morbidity (−0.5) 18 334 b 19 125 b 0.62 (0.48–0.89) c 6 20 , 21 , 23 , 24 , 27 , …”

Water, sanitation and hygiene for the prevention of diarrhoea

“…Our initial attempt at this review nearly foundered. The initial search 13 produced seven quasi-randomized intervention studies with diarrhoea morbidity as the outcome measure, and one with diarrhoea mortality ( Figure 5 , Table 4 ). The mortality study has already been mentioned; 23 the intervention included water supply and education about oral rehydration therapy, which could explain the observed reduction in mortality.…”

“…), of the intervention (is sewerage in Brazil different from pit latrines in Africa? ), on the range of languages accepted (in several recent reviews, 13 , 45 more than a third of useful studies were in Chinese) and on which are regarded as the gravest methodological deficiencies. Each of those questions has more than one reasonable answer.…”

“…Again we followed the Cochrane approved protocol 13 to search for interventions to dispose of human excreta so as to reduce direct or indirect human contact. This includes any steps to remove or contain faeces, such as simple pit latrines, bucket latrines, hanging toilets and composting toilets, and should be contrasted with open defecation.…”

“… Quality assessment No of events Effect Design Limitations Consistency (based on the heterogeneity of the meta) Generalizability to population of interest Generalizability of intervention Intervention Control RR (95% CI) Outcome 1: Diarrhoeal mortality for all ages; Quality: very low 2 8 , 27 RCT and quasi-RCT No placebo, not blinded, one randomized, self-reported and self-defined diarrhoea (−1.5) NA Both Africa, 1 is all ages, 1 under 5s (−0.5) 1 all-cause mortality, 1 diarrhoeal mortality 34 55 Ranging from 0.61 to 0.15 a Outcome 2: Diarrhoeal morbidity for all ages; Quality: very low 38 (30 studies, 5 with multiple arms; arms counted as additional trials) 1–30 RCT and quasi-RCT Only three blinded and placebo, few adequately randomized, most self-reported diarrhoea with excessive recall period. (−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 …”

“…(−1.5) Test for heterogeneity gave significant result (−0.5) Mostly Africa, Latin America and Asia, all ages (−0.5) Moderate and severe morbidity (−0.5) 41 485 b 64 224 b 0.58 (0.46–0.72) c 27 (19 studies, 5 with multiple arms) 1–19 RCT Only three blinded and with placebo, few adequately randomized (−1) Significant heterogeneity (−0.5) Mostly Africa and Latin America, all ages (−0.5) Moderate and severe morbidity (−0.5) 23 151 45 098 0.54 (0.38–0.88) c 4 1 , 5 , 12 Double blind studies Inadequate randomization, high loss to follow-up, coverage not measured (−0.5) Heterogeneity not significant ( P = 0.30) 1 Lat Am, 1 Africa, 1 USA, all ages (−0.5) Moderate and severe morbidity (−0.5) 1912 1987 0.93 (0.70–1.33) c 11 20–30 Quasi-RCT Inadequately randomized, no placebo, mostly self-reported with excessive recall period (−2) Significant heterogeneity (−0.5) Mostly Asia and Africa, all ages (−0.5) Moderate and severe morbidity (−0.5) 18 334 b 19 125 b 0.62 (0.48–0.89) c 6 20 , 21 , 23 , 24 , 27 , …”