Solar disinfection of water for diarrhoeal prevention in southern India

Aims

To evaluate the efficacy and acceptability of solar irradiation in the prevention of diarrhoeal morbidity in children under 5 years of age, in an urban slum in Vellore, Tamil Nadu.

Methods

A total of 100 children were assigned to receive drinking water that had been subjected to solar disinfection in polyethylene terephthalate bottles. One hundred age and sex matched controls were also selected. Both groups were followed by weekly home visits for a period of six months for any diarrhoeal morbidity. At the end of the follow up period, the acceptability of the intervention was assessed by interviews, questionnaires, and focus group discussions.

Results

There was significant reduction in the incidence, duration, and severity of diarrhoea in children receiving solar disinfected water, despite 86% of the children drinking water other than that treated by the intervention. The incidence of diarrhoea in the intervention group was 1.7 per child‐year, and among controls 2.7 per child‐year, with an incidence rate ratio of 0.64 (95% CI −0.48 to 0.86). The risk of diarrhoea was reduced by 40% by using solar disinfection. In qualitative evaluation of acceptability, most women felt that solar disinfection was a feasible and sustainable method of disinfecting water.

Conclusions

Solar disinfection of water is an inexpensive, effective, and acceptable method of increasing water safety in a resource limited environment, and can significantly decrease diarrhoeal morbidity in children.     

Solar disinfection of drinking water protects against cholera in children under 6 years of age.

BACKGROUND AND AIMS: We have previously reported a reduction in risk of diarrhoeal disease in children who used solar disinfected drinking water. A cholera epidemic, occurring in an area of Kenya in which a controlled trial of solar disinfection and diarrhoeal disease in children aged under 6 had recently finished, offered an opportunity to examine the protection offered by solar disinfection against cholera. METHODS: In the original trial, all children aged under 6 in a Maasai community were randomised by household: in the solar disinfection arm, children drank water disinfected by leaving it on the roof in a clear plastic bottle, while controls drank water kept indoors. We revisited all households which had participated in the original trial. RESULTS: There were 131 households in the trial area, of which 67 had been randomised to solar disinfection (a further 19 households had migrated as a result of severe drought). There was no significant difference in the risk of cholera in adults or in older children in households randomised to solar disinfection; however, there were only three cases of cholera in the 155 children aged under 6 years drinking solar disinfected water compared with 20 of 144 controls. CONCLUSIONS: Results confirm the usefulness of solar disinfection in reducing risk of water borne disease in children. Point of consumption solar disinfection can be done with minimal resources, which are readily available, and may be an important first line response to cholera outbreaks. Its potential in chorine resistant cholera merits further investigation.     

Solar disinfection of drinking water protects against cholera in children under 6 years of age

BACKGROUND AND AIMS—We have previously reported a reduction in risk of diarrhoeal disease in children who used solar disinfected drinking water. A cholera epidemic, occurring in an area of Kenya in which a controlled trial of solar disinfection and diarrhoeal disease in children aged under 6 had recently finished, offered an opportunity to examine the protection offered by solar disinfection against cholera.METHODS—In the original trial, all children aged under 6 in a Maasai community were randomised by household: in the solar disinfection arm, children drank water disinfected by leaving it on the roof in a clear plastic bottle, while controls drank water kept indoors. We revisited all households which had participated in the original trial.RESULTS—There were 131 households in the trial area, of which 67 had been randomised to solar disinfection (a further 19 households had migrated as a result of severe drought). There was no significant difference in the risk of cholera in adults or in older children in households randomised to solar disinfection; however, there were only three cases of cholera in the 155 children aged under 6 years drinking solar disinfected water compared with 20 of 144controls.CONCLUSIONS—Results confirm the usefulness of solar disinfection in reducing risk of water borne disease in children. Point of consumption solar disinfection can be done with minimal resources, which are readily available, and may be an important first line response to cholera outbreaks. Its potential in chorine resistant cholera merits further investigation.     

Solar disinfection of water reduces diarrhoeal disease: an update.

349 Maasai children younger than 6 years old were randomised by alternate household to drink water either left in plastic bottles exposed to sunlight on the roof of the house or kept indoors (control). The trial was run in Maasai by Maasai community elders. Children drinking solar disinfected water had a significantly lower risk of severe diarrhoeal disease over 8705 two weekly follow up visits; two week period prevalence was 48.8% compared with 58.1% in controls, corresponding to an attributable fraction of 16.0%. While this reduction is modest, it was sustained over a year in free living children. It confirms solar disinfection as effective in vivo as a free, low technology, point of consumption method of improving water quality. The continuing use of solar disinfection by the community underlines the value of community participation in research.     

Solar disinfection of water reduces diarrhoeal disease: an update

349 Maasai children younger than 6 years old were randomised by alternate household to drink water either left in plastic bottles exposed to sunlight on the roof of the house or kept indoors (control). The trial was run in Maasai by Maasai community elders. Children drinking solar disinfected water had a significantly lower risk of severe diarrhoeal disease over 8705 two weekly follow up visits; two week period prevalence was 48.8% compared with 58.1% in controls, corresponding to an attributable fraction of 16.0%. While this reduction is modest, it was sustained over a year in free living children. It confirms solar disinfection as effective in vivo as a free, low technology, point of consumption method of improving water quality. The continuing use of solar disinfection by the community underlines the value of community participation in research.     

Impact of zinc supplementation on diarrhoeal morbidity in rural children of West Bengal,India

AIM: To determine the role of zinc supplementation in reducing diarrhoeal morbidity in children. METHODS: A randomized, double-blind, community-based intervention study was conducted in 280 rural children aged between 6 and 41 mo. Children were randomly allocated into three groups. One group received a daily dose of 10 mg zinc for 5 d wk(-1), another group received 50 mg zinc once weekly and the remaining group received placebo. Zinc was supplemented for 16 wk from November 1999. Diarrhoeal episodes were detected by weekly surveillance during the supplementation period. RESULTS: Eighty diarrhoeal episodes were detected among 59 children in all 3 groups. The groups were compared with each other at baseline and as regard to the outcome variable (incidence of diarrhoea). The proportion of children suffering from diarrhoea during the period was significantly lower in the zinc-supplemented groups (15.8% in daily and 16.5% in weekly group) than in the placebo group (30.8%). The incidence of diarrhoea in the daily and weekly zinc-supplemented groups was 0.68 and 0.69 episodes child(-1) y(-1), and that in the placebo group was 1.67 episodes child(-1) y(-1) (relative risk 0.41, 95% confidence interval 0.24-0.71). Diarrhoeal incidence of < 4 d duration was found to occur significantly less often in the supplemented groups. There was no difference in diarrhoeal incidence between the daily and weekly zinc-supplemented children. There were no detected adverse reactions in any of the supplemented groups. CONCLUSION: The study indicates that zinc supplementation is effective in reducing diarrhoeal morbidity when administered either daily or in a weekly schedule.     

Rotavirus as an important cause of diarrhoea in a hospital for children in Dammam, Saudi Arabia

A major cause of morbidity and mortality among children in developing countries is acute diarrhoea and rotavirus, a reovirus-like agent, is found to be a leading causative agent. We report here the incidence of rotavirus infection among infants and young children with gastro-enteritis treated at the Children's Hospital in Dammam, Kingdom of Saudi Arabia. One hundred and fifty children, aged between 1 and 60 months, suffering from diarrhoeal illness, were selected as the study cohort; another 150 hospitalized children of the same age group, but not suffering from diarrhoea, served as controls. Sixty-two per cent of the study children complained of watery diarrhoea and 39% of vomiting; all had mild to moderate dehydration. Seventy-two per cent had fever and 30% associated respiratory illness. Worst affected were those 7-12 months old, among whom rotavirus was detected by ELISA techniques in 39.6%, compared with 7.5% of the control children of comparable age group. We could not detect any rotavirus from control children aged over 36 months, whereas approximately 15% of the study children in this age group yielded rotavirus from the stool. The second most common pathogen isolated was Shigella ssp. It was isolated from 18.7% of children under study as against 3% of the controls.     

Epidemiological and clinical characteristics of acute and persistent diarrhoea in rural Bangladeshi children

A community-based longitudinal study of acute and persistent diarrhoea in 705 children less than five years old was carried out for a year in a rural area of Bangladesh. Diarrhoea morbidity data were collected from each study child every fourth day by home visit. Clinical features of diarrhoeal episodes and diarrhoeal management information were documented. The overall diarrhoeal incidence rate in the study children was 4.6 episodes per child per year. The incidence of persistent diarrhoea was 34/100 child-years. Persistent diarrhoea was positively associated with young age and more severe illness, characterized by the presence of clinical dehydration or blood in the stool in the first week. Use of ORT in the first week was positively associated and use of an antibiotic was negatively associated with the occurrence of persistent diarrhoea. Reduced breast-feeding and consumption of cow's milk at some time during the episode were also positively associated with persistence. This would suggest that appropriate fluid and dietary management for all episodes should be the goal. Children with more severe initial illness characterized by the presence of blood in the stool or clinical dehydration should have more careful follow-up to identify persistent episodes and adverse nutritional effects. Breastfeeding should be continued during acute diarrhoea, but the role of ORT, antibiotics and cow's milk deserves further investigation.     

Community-based survey of paediatric diarrhoeal morbidity and home treatment practices in Finland

To determine total diarrhoeal morbidity and current home case management practices, a recall study was conducted among 345 mothers whose 406 children under 5 y of age had had diarrhoea in the past 4 months. The seasonally adjusted annual diarrhoea incidence rate was 0.48 episodes/child/y. For home treatment, increased amounts of fluid were given in 93% and oral rehydration solution (ORS) in 37% of cases. However, when given, ORS was diluted with other fluids in 41% of cases. More than half (55%) of the children received increased or normal amounts of food during the diarrhoeal episode, but 7% of the children were kept fasting for at least 1 d. Use of antidiarrhoeal drugs was minimal (0.7%), but products containing lactic acid bacteria were given in 44% of cases. Case management practice in cases of diarrhoea at home have much improved during the last 20 y, but are still not optimal.     

Recurrent and persistent diarrhoea in a rural Zimbabwean community: a prospective study.

Prospective surveillance of patterns of diarrhoeal disease was conducted in a cohort of 204 young children living in a rural community in Zimbabwe. Trained field assistants recorded morbidity data obtained by weekly recall of mothers. Diarrhoea was defined by a commonly used local word, and a diarrhoea-free gap of three or more days was taken to signify a new attack. Diarrhoea was common in this study population with a peak incidence between 6 and 18 months of age. There was, however, wide individual variability in diarrhoea attack rates (range 0 to 20 attacks) during the 22 month study period. Whilst only 6 per cent of the recorded diarrhoea episodes were persistent (lasting longer than 14 days), a high proportion (26 per cent) of subjects had at least one attack of persistent diarrhoea (PD) during follow up. Children who had frequent attacks of acute diarrhoea also tended to have PD; PD was rare in those with few attacks. Thus, within this uniformly deprived African community, there were individuals who had a much higher susceptibility to diarrhoea compared to others. An understanding of this variability may point the way towards more effective interventions in the control of diarrhoeal disease.     

Infant morbidity in an Indian slum birth cohort.

OBJECTIVE: To establish incidence rates, clinic referrals, hospitalisations, mortality rates and baseline determinants of morbidity among infants in an Indian slum. DESIGN: A community-based birth cohort with twice-weekly surveillance. SETTING: Vellore, South India. SUBJECTS: 452 newborns recruited over 18 months, followed through infancy. MAIN OUTCOME MEASURES: Incidence rates of gastrointestinal illness, respiratory illness, undifferentiated fever, other infections and non-infectious morbidity; rates of community-based diagnoses, clinic visits and hospitalisation; and rate ratios of baseline factors for morbidity. RESULTS: Infants experienced 12 episodes (95% confidence interval (CI) 11 to 13) of illness, spending about one fifth of their infancy with an illness. Respiratory and gastrointestinal symptoms were most common with incidence rates (95% CI) of 7.4 (6.9 to 7.9) and 3.6 (3.3 to 3.9) episodes per child-year. Factors independently associated with a higher incidence of respiratory and gastrointestinal illness were age (3-5 months), male sex, cold/wet season and household involved in beedi work. The rate (95% CI) of hospitalisation, mainly for respiratory and gastrointestinal illness, was 0.28 (0.22 to 0.35) per child-year. CONCLUSIONS: The morbidity burden due to respiratory and gastrointestinal illness is high in a South Indian urban slum, with children ill for approximately one fifth of infancy, mainly with respiratory and gastrointestinal illnesses. The risk factors identified were younger age, male sex, cold/wet season and household involvement in beedi work.     

Early child health in Lahore, Pakistan: VII. Diarrhoea

Mahmud A, Jalil F, Karlberg J, Lindblad BS. Early child health in Lahore, Pakistan: VII. Diarrhoea. Acta Paediatr 1993;390(suppl):79–85. Stockholm. ISSN 0803–5326
This study was carried out to obtain reliable prospective data on the incidence, home management and duration of infantile diarrhoeal disease in a developing and rapidly urbanizing community. Fourteen hundred and seventy six infants from 4 different communities of Lahore, representing different stages of urbanization, were followed prospectively from birth to 2 years of age. Each child had an average of 3.6 episodes of diarrhoea during one year; 4.3 episodes per child per year in the village, 4.4 in the periurban slum, 3.4 in the urban slum and 1.4 in the upper middle (Um) class control group. The maximum incidence of diarrhoeal episodes occurred in children between 9–10 months of age. No sex difference was found. The seasonal variation showed a peak incidence during April-June. Bloody diarrhoea, in 3–5% of the episodes, was predominantly seen in winter months and in older infants. The maximum use of ORS was seen in the Um class (53%). Antibiotics were used in 75% of all diarrhoeal episodes maximally in the Um class, and morphine derivatives in 1% of all cases. The overall incidence of persistent diarrhoea was 14% of all acute cases, being highest in the village (18%), followed by the periurban slum (14%), Um class (10%) and urban slum (8%) with peak incidence occurring in June and July. Our results confirm the magnitude of the problem of diarrhoea. The proper selection of cohorts, the closely controlled prospective and simultaneous follow-up study of these large samples representing different urbanization stages and socio-economic conditions and the new detailed data on the duration of diarrhoeal episodes makes these results of wider international interest in addition to its importance for health planning in Pakistan.     

Copper in drinking water: not a strong risk factor for diarrhoea among young children. A population-based study from Sweden

AIM: To assess whether mean daily intake of copper or maximal concentration of copper in drinking water is related to the incidence of diarrhoea and vomiting among young children. METHODS: Mean daily intake of copper from drinking water was estimated prior to episodes of diarrhoea among 430 children aged 9 to 21 mo. A total of 4703 samples of tap water were collected in the homes of the children. The mean daily intake of copper and the maximal concentration of copper in samples of consumed water were used as measures of exposure. The cumulative incidence of acute diarrhoea and vomiting was studied during 12 wk of follow-up. Cases of diarrhoea caused by viral and bacterial infections were identified. RESULTS: The median copper level of the mean value for each child was 0.61 mg/L with 10th and 90th percentiles of 0.04 and 1.57 mg/L. Among the 430 children, 43 had episodes of acute diarrhoea, of which 23 had no identified viral or bacterial origin, and vomiting was reported in 95 children. No significant associations were found between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting. CONCLUSION: There is unlikely to be a strong association between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting within the range of copper intakes/concentrations studied.     

Aeromonas spp associated with children's diarrhoea in Tehran: a case-control study

The study sought a possible pathogenic role for Aeromonas spp in Tehranian children presenting with diarrhoea. During a 10-month period (February to October 2001), 310 children <10 years of age with diarrhoea and a group of 310 age- and sex-matched controls were selected. Both groups were investigated for diarrhoeal pathogens. Of 310 children who presented with acute diarrhoea, Aeromonas spp was isolated from 14 (4.5%) (A. veronii biovar sobria 8, A. caviae 5 and A. hydrophila 1). The isolation rate was significantly higher than in the controls (p<0.001). Other enteropathogens were also more commonly isolated in children with diarrhoea: 57 (18.4%) Shigella spp (p<0.0001), 8 (2.6%) Salmonella spp (p<0.01), 7 (2.3%) enteropathogenic E. coli (p<0.05) and 8 (2.6%) Giardia lamblia (p<0.01). No enteropathogens were isolated in the control group. Dysentery was the dominant clinical feature in children positive for Aeromonas spp.     

Effect of an Acidified Milk on Diarrhoea and the Carrier State in Infants of Low Socio-Economic Stratum

ABSTRACT. The effect on diarrhoeal disease of an acidified, modified powdered cow's milk infant formula (Pelargon®) was evaluated in 82 infants (Group I) for six months; 104 infants who received the same formula but non acidified, served as controls (Group II). Nutritional status remained satisfactory in both groups throughout the observation period. Some children rejected the taste of the acidified milk. The incidence of diarrhoea was lower in Group I ( p <0.001). The proportion of days in which the children suffered from acute diarrhoea, and the duration of the episodes were also lower in the children given the acidified milk ( p <0.001). The rate of detection of enteropathogens and the species identified were comparable in both groups. Carrier rates for bacterial enteropathogens fell over time in Group I while they rose in Group II ( p <0.001). Carrier rates for enteric parasites were comparable to those expected in our setting for this age group. These results suggest that acidified milk exerts a protective effect against diarrhoeal disease.     

Effect of an acidified milk on diarrhoea and the carrier state in infants of low socio-economic stratum

The effect on diarrhoeal disease of an acidified, modified powdered cow's milk infant formula (Pelargon) was evaluated in 82 infants (Group I) for six months; 104 infants who received the same formula but non acidified, served as controls (Group II). Nutritional status remained satisfactory in both groups throughout the observation period. Some children rejected the taste of the acidified milk. The incidence of diarrhoea was lower in Group I (p less than 0.001). The proportion of days in which the children suffered from acute diarrhoea, and the duration of the episodes were also lower in the children given the acidified milk (p less than 0.001). The rate of detection of enteropathogens and the species identified were comparable in both groups. Carrier rates for bacterial enteropathogens fell over time in Group I while they rose in Group II (p less than 0.001). Carrier rates for enteric parasites were comparable to those expected in our setting for this age group. These results suggest that acidified milk exerts a protective effect against diarrhoeal disease.     

Impact of a standardized management protocol on mortality of children with diarrhoea: an update of risk factors for childhood death

In the developing world, diarrhoeal disease is a significant cause of childhood morbidity especially amongst severely malnourished children. As a direct result of improved acute-phase management of this group of patients, there has been a 47 per cent reduction in the death rate among severely malnourished children hospitalized at the ICDDR,B in Bangladesh. The change in the risk factors for death among children aged under 5 years presenting with diarrhoea was reassessed. The charts of 366 children under 5 years of age who were hospitalized for diarrhoeal disease in the year 1998 were retrospectively analysed. One hundred and eighty-three of these patients died and 183 of those who survived acted as controls. Univariate analysis found 12 significant risk factors on admission that impacted outcome. Only two factors, female sex and positive blood culture, remained significant in the multivariate analysis with odds ratios (95 per cent CI) of 2.05 (1.1-4.0) and 4.6 (1.7-12.4), respectively. Prior to the change in the protocol involving the management of severely malnourished children, only severe malnutrition and non-breastfeeding were found to be significant predictors of mortality.     

Occurrence of diarrhoeal diseases in relation to infant feeding practices in a rural community in West Bengal,India

In a rural community-based prospective study, diarrhoea in relation to the feeding patterns of a cohort of infants was studied. A total of 148 infants between the ages of 0 and 2 months were enrolled and followed until the completion of 1 year of age. Survival analysis showed that by the fourth month of age exclusive breastfeeding dropped by 75%. The proportion of complementary breastfeeding increased from 18.6 to 52.9% during the same period and to 83.7% by the eighth month. This study clearly highlights the tendency for early switch over from exclusive breastfeeding to complementary breastfeeding. Early weaning was associated with an incidence rate ratio (IRR) of 3.02 (95% CI 1.043–8.802). The IRR of 3.02 and its confidence limits (1.043–8.02) suggest a significant protective effect of exclusive breastfeeding against diarrhoea in infants. The results of this study indicate that promotion of exclusive breastfeeding has a potential role to reduce the incidence of diarrhoea amongst infants. The findings of this study will be useful for Diarrhoeal Disease Control Programme in reducing diarrhoeal morbidity.     

Does age at the start of breast feeding influence infantile diarrhoea morbidity? A case–control study in periurban Guinea–Bissau

Colostrum protects the newborn from intestinal infection by its content of secretory immunoglobulin A and other immediately acting factors. It may also induce maturation of the child's gastrointestinal immune defences, thus contributing to the protection against diarrhoeal disease later in infancy. To test this hypothesis, a case–control study on breast feeding and diarrhoea was carried out in a periurban community in Guinea–Bissau. The child's age at the start of breast feeding was ascertained soon after birth ( n = 279). Subsequent cases of acute diarrhoea ( n = 66) were identified at 3–monthly examinations, and four concurrent controls were randomly selected among attendants. Three separate estimates of association showed that the cases tended to have started breast feeding later after birth than the diarrhoea–free controls, but no single test was statistically significant. Early breast feeding might have consequences for diarrhoeal morbidity after the neonatal period.     

Patterns of Breast Feeding in Western Ethiopia and their Relationship to Acute Diarrhoea in Infants

To determine the extent of protection from breast feeding against acute diarrhoea, a cross-sectional study was conducted in rural areas in a western region of Ethiopia, Gamo-Gofa. The standard cluster sampling technique promoted by WHO/CDD Program was used. We employed trained and supervised health workers (physicians nurses, and sanitarians) as interviewers, and a pretested questionnaire was utilized for the purpose. Among a total of 3002 children under the age of 5 years surveyed for diarrhoeal disease morbidity, mortality, and treatment rates, all those 6 months of age and less (n = 331) were taken as subjects to examine the trends of breast feeding and their association with the occurrence of acute diarrhoeal diseases. It was found that out of these 331 infants, 217 (66 per cent) were exclusively breast-fed and 114 (34 per cent) were partially breast-fed. No one in the study group was fully weaned. Out of those who were exclusively breast-fed (n = 217), 25 (12 per cent) had diarrhoea which started within the past 2 weeks of the survey. Among those partially breast-fed (n = 114), 46 (40 per cent) had diarrhoea. The difference in the occurrence of diarrhoea among exclusively and partially breast-fed infants was statistically significant (P less than 0.0001). When infants with partial breast feeding were contrasted with those on exclusive breast feeding, a relative risk of developing diarrhoea of 5.2 (95 per cent confidence interval 3.00, 9.10) was obtained. It is recommended that breast feeding which tends to diminish with urbanization be promoted as one important intervention of the control of diarrhoeal diseases.