Effect of SODIS and Hygiene Behaviour childhood diarrhoea

Transcription

1 WHO Conference, Accra Ghana June 2008 Effect of SODIS and Hygiene Behaviour childhood diarrhoea A quantitative field study in the SODIS project area in the Kibera Slum of Nairobi, Kenya Jürg Graf & Hansi Mosler, Social Psychology University Zürich Regula Meierhofer & Martin Wegelin Eawag/ Sandec Catherine Mwango, KWAHO

2 SODIS Solar Water Disinfection Plastic bottles filled with contaminated water are exposed to full sunlight for 6 hours/ 2 days At 30 C: Solar Radiation Intensity of 500 W/m 2 is needed for 5 hours Above 45 C synergy of : - radiation in the UV-A spectrum - increased water temperature => decrease of exposure time

3 Which pathogens are killed by SODIS? Pathogen Illness Reduction through SODIS ** at water temperatures of 40 C and solar exposure of 6 hours Bakteria E.coli Indikator for Water Quality & Enteritis 3-4 log ( %) Vibrio cholera Cholera 3-4 log Salmonella spp. Thyphoid 3-4 log Shigella spp. Dysentery 3-4 log Campylobact. jejuni Diarrhoea 4 log Yersinia enterocolitica Diarrhoea 4 log Viruses Rotavirus Diarrhoea, 3-4 log Dysentery Polio Virus Polio 3-4 log Hepatitis Virus Hepatitis Red. of cases of SODIS users Protozoa Giardia spp Giardiasis noninfective cysts Cryptosporidium spp. Cryptosporidiasis noninfective cysts (10 hours) Amoeba spp Amoebiais 1 hour above 50 C! cysts inactivated

4 Application of SODIS Only local resources are required: Sunlight and PET-bottles (or glass bottles) SODIS requires sufficient sunlight: clear sky to 50% cloudy 6 hours more than 50% cloudy: 2 days SODIS requires relatively clear water: At a turbidity of more than 30 NTU (water looks milky) the water has to be pretreated using: Flocculation/ Sedimentation or Filtration Flat containers are needed (The UV-A radiation is reduced by 50% at a water depth of 10cm)

5 SODIS Project in the Kibera Slum, Nairobi The Kibera Slum Illegal slum settlement in Nairobi with inhabitants on 250ha Lack of infrastructure (electricity, waste management, sanitation, water supply) 95% of the people below the poverty line and earn less than 1 USD per day The SODIS Project in the Kibera Slum Project Partner: KWAHO (Kenya Water & Health Organisation Promotion of SODIS in the Kibera Slum since July 2005 About people use SODIS for the treatment of their drinking water Combination of SODIS & Hygiene education

6 Study about Water Consumption and Hygiene in the Kibera Slum Goal of the study Evaluation of the project impact Assess the health effects of SODIS through quantification of diarrhoea cases of children < 5 Comparison with families consuming unsafe water Assess hygiene behaviour Duration of the study: December 2005 May 2006

7 Methodological approach A team of 10 trained field workers interviewed 500 households (Monitoring of 717 children below 5 years) gender-mixed teams Survey conducted in 5 villages of the Kibera Slum: Mashimoni A, Mashimoni B, Kisumu Ndogo, Mosque & Daranjani (with inhabitants) Households were selected by random 102 water sample were collected from HH and Water Kiosks Structured questionnaire & observations - Diarrhoea incidence among children <5 (last 2 weeks) - Consumption & specification of drinks (open ended) - Hygiene behaviour (questions & observations) - Beliefs for causes of childhood diarrhoea

8 Results: Water Quality Analysis (E.coli) Number of samp samples 7 3 none up to 10 between 11 & 50 Water from Water Kiosks 2 highly polluted : between 51 & 100 between 101 & 200 CFU/100ml between 201 & between more than 301 & Number of samp samples 7 8 none up to 10 between 11 & 50 Raw Water in Households 3 highly polluted : between between 51 & & 200 CFU/100ml 6 4 between between 201 & & more than 501 Number of samp SODIS Water 35 samples highly polluted : none up to 10 between 11 & 50 between 51 & 100 CFU/100ml between 101 & 200 between 201 & 300 between 301 & 500 more than 501 Comparison Water Sample Water Kiosk Household SODIS > 50 E.Coli/100 ml % of total Samples Observations: part of the water distributed is highly contaminated further pollution in households by inadequate water handling SODIS provides safe water by proper application

9 Results: Diarrhoea Incidence SODIS non-user n=155 SODIS user n=345 Total n=500 Diarrhoea incidence 69.7% 15.9% tot HH without diarrhoea 67.4% raw water : 7 (4.5%) no raw water: (30.3%) raw water : 3 (0.9%) no raw water : (84.1%) raw.: 10 no raw.: tot HH with diarrhoea 32.6% raw water: 86 (55.5%) no raw water : (69.7%) raw water: 17 (4.9%) no raw water: (15.9%) raw.: 103 no raw.: % of 500 interviewed HH used SODIS for water treatment 84% of SODIS users consumed safe drinks and had no diarrhoea 15.9% of SODIS users had diarrhoea (5% consumed unsafe drinks) 30.3% of Non-users consumed safe drinks and had no diarrhoea 63.1% of all with diarrhoea consumed unsafe drinks! consumption of untreated water leads to a high diarrhoea risk

10 Results: Relation diarrhoea & unsafe drinks % diarrhoea incidence 78% of all caretakers give only safe drinks to children <5 22% of caretakers provide 0.1% to 50% unsafe drinks even a minor consumption of unsafe drinks (up to 10%) leads to a high incidence of diarrhoea (80%)!

11 Results: Hygiene Behaviour Are the hands of the young children around clean? Are the hands of the respondent clean? Is the water storage in the household covered? Is soap in the household available? Yes Percent of households with incidence of children's diarrhoea No 71.2% of HH with risky hygiene behaviour suffer from childhood diarrhoea 26.1% of HH with improved hygiene behaviour suffer from childhood diarrhoea SODIS-user Non-user Are the hands of the young children around clean? Are the hands of the respondent clean? Is the water storage in the household covered? Is soap in the household available? Percent of households that use SODIS 71.2% of SODIS users show improved hygiene behaviour 33.45% of Non-users show improved hygiene behaviour

12 Conclusions The promotion of SODIS in combination with hygiene and health education leads to a significant diarrhoea reducation (15.9% vs. 69.7%) A minority of the population still gives raw water to their young children. The same group shows more hazardous hygiene behaviour (lower socio-economic status) Need to develop strategies to better reach marginalized segments of the population

13 Other SODIS health impact studies Epidemiological Health Impact Studies: Kenya; Masaai children in the 90ies: % diarrhoea reducation among children below 5-86% reducation of cholera cases Bolivia; HIS of the Swiss Tropical Institute on 200 children: - >35% diarrhoea reduction India; 2006 HIS of Univ of Uppsala Sweden and Christian Medical College Vellore, India on 100 children: - 40% diarrhoea reduction Project Evaluations: Usbekistan, Pakistan, India, Nepal, Kenya, Indonesia: ~50% diarrhoea reduction

14 Worldwide use of SODIS

15 Factors influencing the uptake of SODIS Availability of PET bottles Motivated promoters Intervention period of several months Information provided through several channels Visibility of the method and application - opinion leaders use SODIS - many bottles exposed in community - posters and demonstrations - prompts Education level of users Institutionalization: Dissemination of the message through official channel (health sector)