It is well known that water treatment at the household level can lead to dramatic improvements in drinking water quality. But does Household Water Treatment and Safe Storage (HWTS) also have global relevance? What are the potential treatment solutions and how do they function? Is there a standard strategy for successful HWTS implementation, or can we identify key components which make programs more likely to succeed? In this course you will learn about the most important water treatment methods at household level, successful implementation strategies and about assessing the impact of HWTS. MOOC SERIES “SANITATION, WATER AND SOLID WASTE FOR DEVELOPMENT” : This course is one of four in the series “Sanitation, Water and Solid Waste for Development". FRANçAIS: Dans ce MOOC, vous allez apprendre les plus importantes méthodes de traitement de l'eau au niveau des ménages, les stratégies pour une mise en œuvre réussie et l’évaluation de l’impact du traitement et stockage sûr de l'eau à domicile. ESPAñOL: Aprende acerca de los métodos más importantes de tratamiento de agua a nivel domiciliario, de estrategias de implementación eficientes y de la evaluación del impacto del tratamiento doméstico y almacenamiento seguro del agua.
4.2 Targeted approaches
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From the course by École Polytechnique Fédérale de Lausanne
Introduction to Household Water Treatment and Safe Storage
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École Polytechnique Fédérale de Lausanne
132 оценки
From the lesson
Implementation strategies for HWTS
During week 4 we analyse different approaches that have been successfully applied. We highlight key components which make programs more likely to succeed. We ask the questions, what is required that the most vulnerable populations use HWTS correctly and consistently over the long-term? In separate modules we consider the special case of HWTS in emergency response and provide information about the role of government bodies.
Meet the Instructors
Rick JohnstonDr.
Joint Monitoring Programme / WHO
Sara MarksDr.
Sanitation, Water and Solid Waste for Development / Eawag
In the last module, we talked
about different strategies for promotion of HWTS.
If the objective is purely to maximize profit, any
reductions in disease that result are nice, but are secondary.
If on the other hand the goal is
to maximize a social good like reducing diarrheal disease,
then interventions will often aim to target the
most vulnerable populations those who are consuming unsafe water.
And of course the HWTS technology needs to be effective and applied consistently
We've already looked at the base of the pyramid but a good strategy can
be to promote HWTS in special settings where either people face particular health
risks or where they're more likely to take up and consistently apply a new behavior.
And today we'll look at some examples of
this approach in schools, and integrated with health interventions.
There's been a lot of interest in improving water, sanitation and hygiene in schools.
One reason is that many children suffer from
diarrhea and other disease related to poor wash.
Another argument is that inadequate wash facilities prevents
students, especially girls, from attending and completing school.
If there are no latrines, and girls can't urinate privately
during the day, they may simply not go at all.
School boys, on the other hand, often have no problems urinating in the open.
It is somehow more acceptable.
In many cultures, for boys than girls.
Finally, a third argument for WASH in schools, is that by reaching children when
they are young and impressionable, good habits
can be established which will last a lifetime.
So, there are many reasons to work with WASH in schools and there
are more and more examples of combining and integrating HWTS with school settings.
Demand is generally created through school level demonstrations which may
involve water quality testing to
demonstrate the effectiveness of treatment.
And in some cases children are asked to bring some messages back to their homes, or for
example, to demonstrate SODIS to their parents, in
an effort to stimulate demand within the broader community.
School interventions tend to be supported technically by an
NGO or other development partners in at least
the initial phases, but there's always close collaboration with,
the relevant government partner, such as the Ministry of Education.
Costs are generally not recovered from the students, and schools
themselves usually require financial support,
especially during the startup phase.
But even during routine implementation when financial
resources are needed, for operation and maintenance.
The SODIS reference center at Sandec has developed the Safe Water School Project,
along with antenna technologies, Helvetas Swiss
Intercorporation, and supported by the Swiss government.
The project launched in 2011, and reached, 143 schools in Bolivia, Kenya, and Haiti.
In Bolivia, the project is headed by the Fundación SODIS and covers all 40 primary
schools in Tiquipaya, a city of 50,000 near Cochabamba.
The project has recently expanded into six secondary schools
and surrounding communities as well as a second municipality.
But intervention takes an integrated
approach covering water, sanitation, and hygiene,
including different types of HWTS,
mainly SODIS and chlorination.
Each school develops a safe water station for every
classroom, like the one shown here. And demonstrates both SODIS,
we can see some of the plastic bottles down here, and chlorination using
electrolytically generated chlorine with the mini-WATA
generator developed by Antenna to produce a chlorine solution from salt and water.
The project also trains people to make their own soap,
which is apparently fun, as well as good for handwashing.
The safe water school project is planned and implemented with local
authorities, in this case the municipality,
and the district education ministry of Tiquipaya.
The project is monitored at the school level by
safe water committees with two to three teachers
and ten students per school, and at the municipal
level the Fundación SODIS the support NGO monitors the project.
And after the project is complete, this
is taken over by the District Education Authorities.
A key part of the intervention is water quality testing.
This serves to help monitor use of HWTS at the
schools, as well as to create demand for safe water.
The schools mostly use piped water, but the supply is intermittent
and there is almost always some detectable E. coli in the water.
Here, you see a student from one of
those safe water committees testing for residual chlorine.
With a safe storage container there and below these are
some of the E. coli testing plates that are used.
Students and teachers alike enjoy the water quality testing, and it has
proven very effective at convincing people that the treatment is important and works.
The Safe Water project provides initial training and
support for monitoring. But once the program is
well established the municipality will take over with
the NGO Fundación SODIS available for technical support on request.
It's hard to measure the impact of such interventions.
Conceptually at kind of the top level, having safer water
could lead to improved enrollment, attendance and completion of school,
and perhaps better academic performance.
One might also expect less diarrheal disease though
there are many exposures outside the school environment.
It's perhaps more realistic to look for improved water and sanitation
conditions in the schools and possibly in the homes of students.
And at a minimum to have increased
awareness about drinking water quality and WASH.
One of the most rigorous evaluations of WASH in schools
to date was done by Matt Freeman at Emory University.
He and his co-authors did a randomized
trial in 185 primary schools in Western Kenya.
This picture is from a different WASH in Schools project, also in Kenya.
All of the schools except for controls, were
provided with hygiene promotion and an HWTS system,
consisting of safe water storage containers and a
year's supply of Water Guard liquid chlorine solution.
Half of the schools were also provided with additional latrines.
And if schools did not have a year-round water
source within one kilometer, and no improved water source
within two kilometers, they were considered water-scarce, and the
project provided them with a new water supply facility,
either a bore hole, or a rain water harvesting tank.
At a follow-up visit six months after the intervention, all
of the schools, including the control schools, had better access to
improved sources of drinking water, and about two thirds of
water samples included residual chlorine,
indicating that water treatment was ongoing.
Students reported much greater availability
of drinking water, hand washing water,
and soap, which was also confirmed by the evaluation teams.
There was also a significant reduction in diarrheal disease by more than 50%.
But this was found only in the water-scarce
schools, which received a new water source.
So at least in this one case,
we have evidence of improved knowledge and behavior,
at least after six months, which may not
alone be sufficient to reduce diarrheal disease burden.
It's a natural idea to link HWTS with health interventions.
HWTS is, after all, a health intervention itself, to reduce diarrheal disease.
And some of the people most vulnerable to diarrheal disease
might already be in contact with the health care system.
So reaching them could be easier and
more cost effective through an integrated approach.
HWTS promotion maybe more credible when it comes from a
health worker, rather than a water engineer or an NGO.
And finally there can be mutual reinforcements,
so that not only is HWTS is more effective when paired
with another health intervention, but that other intervention can also benefit.
Otherwise there would be little reason for them
to take on the additional messages of HWTS.
We'll look at two kinds of integration with health care systems.
First, around child and maternal health
taking the specific example of antenatal care.
And second with a context of HIV/AIDS management.
There are other potential linkages, for instance
diarrheal disease compounds and is compounded by malnutrition.
So there's interests in integrated interventions there.
And there are even potential links with water related diseases like Dengue fever.
Since the mosquitoes that carry the Dengue virus
like to lay their eggs in water containers
a key intervention for vector control is promotion
of household water storage containers with tightly sealed covers.
But, in the interest of time, today we'll just look at antenatal care and HIV AIDS.
First, antenatal care, or ANC.
This example is from Malawi.
Where Population Services International had been marketing WaterGuard since 2002.
But several years on, awareness was high,
but uptake was still low.
In 2007, the Ministry of Health launched a project to promote HWTS alongside
antenatal care visits, 15,000 pregnant women attending their first
antenatal care visits were given hygiene promotion and free hygiene kits
which included a plastic bucket with a tap and samples of WaterGuard.
The women were then visited in their homes
afterwards by health workers and if they return to
the health clinic for their second, third, or
fourth ANC visits, they were given free water-guard refills.
They also got refills if they delivered their babies
in a healthcare facility, or made post natal care visits.
Now the maternal and child healthcare sector in Malawi
was very concerned since most women attend one antenatal visit.
But only about 20% complete the recommended round of four ANC visits.
And less than three-quarters of them deliver in a healthcare facility.
And less than half make a timely post-natal visit.
The U.S. Centers for Disease Control evaluated the intervention
with follow-ups one year and
three years after the intervention, which included surprise visits,
testing for residual chlorine, and visual confirmation of WaterGuard bottles.
After one year, there was a tremendous increase in confirmed use
of WaterGuard, from 1% to 62% among the women in the program.
Use of the safe storage containers was almost 100%.
And the evaluation also looked at the practices
of close friends and relatives with young children.
And so a large increase there as well, up to 27% confirmed use.
It seems like pregnancy and childbirth represent teachable moments.
When mothers are very concerned about the health of their new child.
There are a lot of changes and they're changing many behaviors.
If you are a parent, you know very well that once you have children, especially
your first one, you change a lot of
your routine behaviors, and that is an understatement.
Anyway those same households were revisited two
years later and while there was a
substantial decline in confirmed use among both
direct participants and the close friends and neighbors.
These numbers still represent a fairly high sustained use.
Qualitative research confirmed that the health care
workers that were involved in promotion were considered
to be highly credible by the women and
that this influenced them to continue using HWTS.
What is very interesting about this study is that the women who were enrolled
were much more likely to return to the health clinics for repeat ANC visits.
More than half of the women completed the full four ANC visit cycle.
90% of them delivered their babies in a health clinic.
And, 90% also made a post-natal checkup, within six weeks.
And these numbers are much higher than average for that region.
So this HWTS intervention turned out to
be extraordinarily effective, for the maternal and
child health people, not only for those
more concerned about water and diarrheal disease.
And where both parties benefit, integration is much more likely to
succeed and this pilot has since been scaled up in Malawi.
If one strategy in optimizing health gains from HWTS is to target the
vulnerable, it makes a lot of sense to work on interventions on HIV/AIDS.
People living with HIV have weakened immune systems
and are particularly vulnerable
to infections, including water-borne diseases.
They may become sick, with lower pathogen loads, and an infection
that could be minor in a healthy person can be life-threatening.
Cryptosporidium is a particular risk.
And a recent review of people living with HIV/AIDS, in low resource
settings, found Crypto to be the
most common waterborne pathogen causing diarrhea,
and was a significant cause of mortality.
So HWTS has been recognized to be an important
element of preventative care for people living with HIV AIDS.
And while there are not many studies out there yet.
There is increasing evidence that HWTS uptake
is higher in interventions with people with
HIV AIDS than in conventional interventions, and
that there is significant reduction in diarrheal disease.
There are even a few studies showing that HWTS may slow the progression of AIDS.
One study, for example, found that people with
HIV who received an insecticide treated bed net
a light straw water filter, experienced less severe drops in their
CD4 counts, which is an indication of the severity of the disease.
Participants were 27% less likely, to have their CD4
counts drop to a critical level, within the study period.
Here is an example of an integrated intervention.
And I'd like to thank Rachel Peletz for this example and the use of her photos.
Rachel conducted a randomized control trial in Peri-urban Zambia
which enrolled 120 households with children under the age two.
Including a hundred HIV positive mothers and 20 HIV negative mothers.
Half of the households were provided with
a water filter and a safe storage container.
And the other half were used as controls.
Though after one year, the control households also received the intervention.
Here you see the water filter, and by now can
you all tell me what kind of filter this is?
Post it on the discussion forum.
Participants, who are trained by the project fieldworkers, who
made monthly follow-up visits for a year after which the
control households received their filters and then a final follow
up visit was made two years after the initial distribution.
Follow up visits were unannounced and involved water quality testing as
well as, recording of diarrhea and reported use of the filter.
In addition, an objective nutritional measure was
used called the weight for age Z-score.
Throughout the evaluation period, filter use was extremely high.
People reported using the filter in 96% of visits.
This was confirmed by the field workers in around 85% of visits.
And on the very last visit, after two years of use.
92% of households were confirmed users.
Of the people who reported using the
filters, 95% reported not using any other source
of drinking water in the last two days, either for the mother or for the child.
These are very high numbers compared to other studies.
That could have been even higher, except that two of
the filters were eaten by rats, the plastic tubing part.
So, the evaluation found that the filters showed more than two log removal
and here it's likely that there were detection limit problems
preventing measurement of higher LRVs.
You see if the raw water contains 100 CFU per 100 mLs
and you measure less than one CFU per 100 mLs, all
you can say is that there was at least two log
removal you don't know if it's three or five or nine log.
And if you compare the geometric means of water in intervention and
control households you can see something like two orders of magnitude difference.
The evaluation also found more than a 50% reduction in diarrheal disease.
Which again is high compared to other studies.
And also found that people consuming more contaminated water,
more highly contaminated water, experienced a higher risk of diarrhea.
However, they didn't find any significant difference in the weight for age z-score.
This module has drawn heavily on a few scientific studies.
And you can find the full articles here.
Many of them are freely available online.
And the pdf version of this lecture has the hyperlinks for you.
And these are more general resources which
were very useful in putting together this module.
Again, the pdfs include the hyperlinks for all of these reports.
So to summarize, there's a lot of
interest in integrating HWTS promotion with other interventions.
There may well be a better chance at
realizing health gains because it is easier reaching people
at higher risks of infection, and because those
people might trust the people delivering the message more,
if they're respected figures like teachers or health care workers.
It's also more cost efficient to reach these
people by bundling interventions into an integrated package.
There's suggested evidence, and a lot of enthusiasm so far,
for integration into school programs, but there's stronger evidence that
shows that when HWTS is integrated into other health initiatives
both the objectives can have a better chance of success.
In the next module we'll look at another kind
of targeted application of HWTS, which is emergency response.
This module will be given by a guest
lecturer, Dr. Danielle Lantagne of Tufts University in the USA.
Don't miss it.
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