Combined Handwashing and Drinking Water Treatment for Diarrhea Prevention,
a Randomized Control Trial
Steve Luby, Centers for Disease Control
Bleach treatment of home drinking water
Setting yearDiarrhea reduction
Montero, Bolivia 1994 44%Nukkus, Uzbekistan 1995 62%Kitwe, Zambia 1998 48%Karachi, Pakistan 2001 72%
Flocculant-Disinfectant (PūR®)
• Developed by Procter & Gamble
• Combines – Precipitation– Coagulation– Flocculation– Disinfection
Handwashing reduces diarrhea
47%Meta- analysis of handwashing studies (Curtis, V. Lancet Infectious Diseases, 2003; 3:275-281.)
Study Objectives
• Evaluate the effectiveness of flocculant-disinfectant in reducing diarrhea
• Measure the marginal health benefit in reducing diarrhea by adding handwashing with soap to improved drinking water.
Karachi Squatter Settlements
• Sewage contaminated drinking water– 10,900 colony forming
units of fecal coliforms per 100 ml
• Feces contaminated environment
Disease Setting
• 10% of children die before their 5th
birthday– 40% from diarrhea
• 40% of children are malnourished
Cluster randomized study
• Study area divided into 47 neighborhoods
• Randomly assigned to– Bleach – Flocculant-disinfectant– Soap– Flocculant-disinfectant +
Soap– Control
Study Groups
Intervention neigborhoods households
Flocculent-disinfectant 9 262
Handw ashing w ith soap 9 262
Flocculant-disinfectant + Handw ashing w ith soap 10 266
Bleach 10 265
Control 9 282
Community based behavior change
• HOPE– Local non-
government organization
– Provide community based health care and development
Bleach Group
• Provided– Local vessel– Dilute bleach weekly
• Instructions:– Add one bottle of dilute
bleach per vessel– Wait 30 minutes– Drink only bleach treated
water
Flocculent-disinfectant Group
• Provided– bucket– spoon – cloths– local vessel– flocculent-disinfectant
weekly
Handwashing PromotionHouseholds visits, at least weekly– Discussions in
households native language
– Pictures used to promote discussions about handwashing
– Questions answered– Diarrhea data collected– Soap re-supplied
Soap group instructions
Wash hands thoroughly lathering with soap
• After– Defecation– Cleaning an infant
• Before– Preparing food– Eating– Feeding an infant
Primary Outcome
• Diarrhea : 3 or more loose stools in a 24 hour period
• Longitudinal prevalence of diarrhea:
Number of days with diarrheaNumber of days of observation
Baseline Household Characteristics
Bleach Floc Floc + Soap
Soap Control
Persons per household 9.4 10.1 9.3 9.2 8.8
Children <5 yrs per house 1.7 1.8 1.8 1.7 1.8
Maternal literacy 35% 30% 30% 32% 37%
Income < $60 per month 51% 51% 56% 51% 56%Handwash station with soap observed
24% 23% 21% 22% 24%
Bar soaps bought last 2 weeks
1.1 1.2 1.2 1.2 1.2
Primary Drinking Water SourceBleach
(%)Floc (%)
Floc + Soap (%)
Soap (%)
Control (%)
Municipal supply in house 30 37 28 28 33 Municipal supply at com mcommunity tap 29 36 38 42 37 Tanker truck 18 12 14 15 12 Water bearer 13 10 10 11 13 Tubewell 10 5 10 11 13
Precipitation in Karachi 2003
020406080
100120140160180200
Apr May Jun Jul Aug Sep Oct Nov Dec
Rai
nfal
l (m
m)
50 year mean July rainfall
USDA Weekly Weather and Crop Bulletin, 2003
Diarrhea longitudinal prevalence by week and intervention
0
2
4
6
8
10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37%
per
son
days
with
dia
rrhe
a
Control
Apr May Jun July Aug Sep Oct Nov Dec
Diarrhea longitudinal prevalence by week and intervention
0
2
4
6
8
10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37%
per
son
days
with
dia
rrhe
a
Control Bleach
Apr May Jun July Aug Sep Oct Nov Dec
Diarrhea longitudinal prevalence by week and intervention
0
2
4
6
8
10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37%
per
son
days
with
dia
rrhe
a
Control Bleach Floc
Apr May Jun July Aug Sep Oct Nov Dec
Diarrhea longitudinal prevalence by week and intervention
0
2
4
6
8
10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37%
per
son
days
with
dia
rrhe
a
Control Bleach Floc Soap
Apr May Jun July Aug Sep Oct Nov Dec
Diarrhea longitudinal prevalence by week and intervention
0
2
4
6
8
10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37%
per
son
days
with
dia
rrhe
a
Control Bleach Floc Soap Soap+Floc
Apr May Jun July Aug Sep Oct Nov Dec
Diarrhea longitudinal prevalence by treatment group
0.00 1.00 2.00 3.00 4.00 5.00 6.00
% person days with diarrhea
Floc+SoapSoapFlocBleachControl
-55%
-51%
-64%
-55% (-17%, -80%)*
*95% CI
(-12%, -76%)
(-29%, -90%)
(-18%, -80%)
Karachi Floc Health Study, 2003
Diarrhea longitudinal prevalence by treatment group
0.00 1.00 2.00 3.00 4.00 5.00 6.00
% person days with diarrhea
Floc+SoapSoapFlocBleachControl
-55%
-51%
-64%
-55% (-17%, -80%)*
*95% CI
(-12%, -76%)
(-29%, -90%)
(-18%, -80%)
Karachi Floc Health Study, 2003
Diarrhea longitudinal prevalence by age and treatment group
0
5
10
1 2 3 4 5Years
% p
erso
n da
ys w
ith d
iarr
hea
ControlBleachFlocSoapSoap+Floc
<1 1-2 2-5 5-15 >15
Karachi Floc Health Study, 2003
Diarrhea longitudinal prevalence by age and treatment group
0
5
10
1 2 3 4 5Years
% p
erso
n da
ys w
ith d
iarr
hea
ControlBleachFlocSoapSoap+Floc
<1 1-2 2-5 5-15 >15
40%
Karachi Floc Health Study, 2003
Diarrhea longitudinal prevalence by age and treatment group
0
5
10
1 2 3 4 5Years
% p
erso
n da
ys w
ith d
iarr
hea
ControlBleachFlocSoapSoap+Floc
<1 1-2 2-5 5-15 >15
40%
73%
Karachi Floc Health Study, 2003
Conclusions
• Flocculant-disinfectant water treatment markedly reduced diarrhea in this vulnerable population
• Handwashing with soap markedly reduced diarrhea in this vulnerable population
• Adding handwashing with soap to improved drinking water, did not further reduce diarrhea
• No single intervention was significantly more effective in reducing diarrhea than any other
Limitations• Courtesy bias possible
– Interventions were not blinded– Diarrhea was based on self report
• People use products differently when they are not in a study– It is possible that with less regular use of water
treatment and handwashing there could be an additive benefit
Next Steps
• Work to bring effective interventions to scale
• PuR is being sold in Pakistan– Follow sales for sustainability– Assess health impact among users
• Evaluate combined interventions in other settings