If you’ve been following WSUP’s research activities, you’ll know that one of our most exciting pieces of work is the evaluation of the health impacts of our sanitation programme in Maputo (Mozambique). This major study, funded by USAID, is being led by the London School of Hygiene and Tropical Medicine (LSHTM). The research is looking at a number of related questions: will this communal toilet intervention have an effect on health, and more specifically, will any effects be dependent on population density? (We would expect the positive effect on health to be stronger in areas with higher population density) It’s a fascinating and innovative study in many respects, not least because of the wide range of health metrics being measured: not just self-reported diarrhoea incidence (the common measure, widely suspected to be unreliable), but also a bunch of other metrics including child height and weight, parasites in child stools, and biochemical markers of viral and parasite infection. Plus at the same time other researchers will be applying the Gates-supported SaniPath approach to get a measure of degree of faecal contamination of the local environment. Baseline measures have started, and data collection will be continuing in line with toilet construction and inauguration-into-use over the coming year. It’s one of the most exciting health impact evaluations in the urban context to date, and WSUP is proud to be providing the intervention to be rigorously tested! If you want out find out more, check out this very interesting presentation recently presented by the lead researchers to USAID’s Sanitation Working Group in Washington.

1. The MapSan Trial
A controlled before‐and‐after (CBA)
study of shared sanitation in
Maputo, Mozambique
Joe Brown (GT)
Oliver Cumming (LSHTM)

2. LSHTM
Oliver Cumming
Olimpio Zavale
Wolf Schmidt
Sandy Cairncross
GT
Joe Brown (PI)
Jackie Knee
Other students
UNC
Pete Kolsky
Jamie Bartram
Jill Stewart
David Holcomb
UFL
Song Liang
Rick Rheingans
WSUP
Guy Norman
Carla Costa
Vasco Parente
World
Bank WSP
Peter Hawkins
USAID
URC
TRAction
The team:
• Study Management
• Research
• Intervention
MISAU
Dr Rassul Nala

3. Do we really need another
sanitation trial?

4. Recent sanitation trials
• Alzua et al 2015
• Patil et al 2014
• Clasen et al 2014
• Hammer & Spears 2013
• Cameron et al 2012
What have these trials taught us?
• It is very hard to convince people people in rural settings to invest in and use sanitation
• Wide variation in measured health effects between studies
• Communicate findings carefully
What have these trials not addressed?
• High density informal settlements
• Urban onsite sanitation with facilities shared by multiple households
• Enteric infections linked to specific transmission pathways
• Enteric infections linked to anthropometric outcomes

6. Primary study questions
1. Can urban, on‐site, shared sanitation reduce
risk of enteric infections in children?
2. Do enteric infection risks and the effects of
urban sanitation vary by localized population
density?

7. Study rationale
Currently…
•Progress on urban sanitation slow in sub‐Saharan Africa
•Low priority sometimes afforded to urban (onsite) sanitation
•Costs sometimes perceived as prohibitive
•Perceived absence of safe, viable and cost‐effective interventions for
slums
•Lack of evidence for the effects of onsite urban sanitation interventions
Questions from policy and practice community
•Is sanitation more important in high density settings
•Uncertainty around the benefits
•Uncertainty around the benefits for shared sanitation
•Does “shared sanitation” count as “improved sanitation” ?

8. Is it plausible that sanitation‐related
disease transmission varies by
population density?
Higher concentration of environmental
contamination – more feces, less space
Higher risk of exposure – environmental
pathways and person‐to‐person

9. ”It is… a well‐
known fact that
the evil effects of
an increased
aggregation of
population are
much more
apparent during
the early years of
life”
SOURCE:
Williamson (1911)

10. Intervention: urban, shared
private sanitation by WSUP
12‐20 people (3‐5 HHs)
20 – 100+ people

11. Study design
Controlled before‐and‐after (CBA)
Children after
new sanitation
Children before
new sanitation
Children with
existing shared
sanitation
Children with
same shared
sanitation
∆
∆
12 months

12. Study design
• Controlled before‐and‐after (CBA)
– Why not an RCT?
• Not possible to randomize
• Demand and use
• 380 children with new‐and‐improved shared
sanitation, 380 controls with existing shared
sanitation
• Allocation according to WSUP formula for siting,
matched on site criteria, time of enrollment, size

13. Before

24. After

26. Site selection: intervention
• (1) sites within the pre‐defined project geographical scope;
• (2) residents must be currently using shared sanitation in poor
condition, based on inspection by WSUP engineers;
• (3) sites must meet WSUP criteria for a minimum number of
beneficiaries (15 for shared latrines, 25 for CSBs);
• (4) sites must have a legal piped water connection nearby for
possible use with pour‐flush latrines;
• (5) residents must convey stated demand for improved sanitation
and have a stated interest in contributing to cost: 10% total cost of
the communal sanitation blocks or 15% of the cost of shared
latrines, divided by the beneficiary households and over 12
months following the start of construction;
• (6) sites must have available space to implement the new facility
(often replacing the space occupied by existing shared facilities);
• (7) sites must be accessible for transport of materials during
construction and to allow for later tank emptying.

27. Control selection
• Come from a similar site that will not receive a
shared latrine
– Cluster of households that share a latrine in poor
condition, with 15+ people, at least 1 child
• Some will be in the 11 JSDF bairros, some in
other nearby bairros that are similar

28. Site selection: control
• (1) sites within the pre‐defined project geographical scope;
• (2) residents must be currently using shared sanitation in poor
condition, based on inspection by WSUP engineers;
• (3) sites must meet WSUP criteria for a minimum number of
beneficiaries (15 for shared latrines, 25 for CSBs);
• (4) sites must have a legal piped water connection nearby for
possible use with pour‐flush latrines;
• (5) residents must convey stated demand for improved sanitation
and have a stated interest in contributing to cost: 10% total cost
of the communal sanitation blocks or 15% of the cost of shared
latrines, divided by the beneficiary households and over 12
months following the start of construction;
• (6) sites must have available space to implement the new facility
(often replacing the space occupied by existing shared facilities);
• (7) sites must be accessible for transport of materials during
construction and to allow for later tank emptying.

36. What we’re measuring
Compliance
Intermediary
outcomes
OutcomesFidelity
Covariates
Stratification variables

37. Measuring density
(1) Number of total people/children under 5 within 50 m of the
center of a given household, measured in a direct line, with
all members of any household touched by the line included ;
and
(2) Number of total people/children within 100 m
(3) Number of people/children under 5 within the shared space
as defined by a household cluster (common area shared by
households sharing the latrine)
Median, tertiles, quintiles

38. Shared space/compound density
• Planimeter ‐ GPS Area Measure v 1.0.0 by
Vistech

39. Visit 1: before hand over
• Area of household and common areas measured for
density calculation
• Observational data
• Informed consent
• Age and weight of all children
• Saliva samples
• Brief household survey for all households with children
• Leave stool sample containers
• Leave fly traps
• Make arrangements with household to come back next
day

40. Visit 2: next day
• Collection of stool samples to take to MISAU.
• Drinking water samples
• Soil samples
• Collect fly samples

41. Visit 3: point of handover
• De‐worming: each child over 12 months
• Single‐dose albendazole (a broad spectrum de‐
worming treatment) will be offered to everyone in
intervention and control households (and their entire
compounds)
• Exceptions: pregnant women in first trimester and
children under 12 months.
• Ministry of Health (MISAU) staff, working within the
National Deworming Campaign (NDC), will administer
albendazole in accordance with MISAU standard safety
protocols and dosage guidelines.
• Current dosing guidelines are to administer 400 mg for
all ages (except for children between 12 and 24
months, who receive 200 mg in a suspension).

42. Visit 4: one year later
• Observational data
• Age and weight of all children
• Saliva samples
• Brief household survey for all households with
children
• Leave a stool sample container
• Leave fly traps
• Make arrangements with household to come
back next day

43. Visit 5: next day
• Collection of stool samples to take to MISAU.
• Drinking water samples
• Soil samples
• Collect fly samples
• De‐worming: each child over 12 months
(albendazole)

44. Outcome measures
• Primary outcome
– Combined prevalence of non‐STH enteric infections in
children under 5
– Enteric infections: STH, Campylobacter, C. difficile, Toxin
A/B, ETEC LT/ST, STEC; Salmonella, Shigella, V. cholerae, Y
enterocolitica, adenovirus GI/GII, RV A, Giardia,
Cryptosporidium, E. histolytica
• Secondary outcomes
– 1. Combined prevalence of STHs in children under 5 (re‐
infection): Ascaris lumbricoides, Trichuris trichiura,
hookworm, Enterobius vermiculare, Taenia spp.,
Hymenolepis spp., and Strongyloides stercoralis
– 2. Reported diarrhea, 7 day recall (self‐report)

45. Outcome measures, continued
• Tertiary outcome measures
– Measures of environmental enteric dysfunction
(EED)
• Myeloperoxidase, alpha‐anti‐trypsin, neopterin
– All‐cause mortality
– Anthropometry
• WAZ, LAZ, WHZ
– Salivary IGF‐1

46. Environmental metrics
• Household water samples, as an indicator of
household hygiene
• Soil samples
• Fly samples
• A subset of samples will be tested for Bacteroides,
E. coli, Enterococci, and pathogens
• Sanitary surveys

47. Water
Enteric
infections
Food
Hands
Flies
Soil &
surfaces
Enteric
infections
SANITATION
WATER
QUALITY
HAND WASHING
WATER QUANTITY

48. Extensions
• SaniPath partnership on environmental
metrics
• Rotavirus vaccine blunting nested cohort
study
• Long‐term child growth cohort

49. Thank you
oliver.cumming@lshtm.ac.uk
joe.brown@ce.gatech.edu
ACKNOWLEDGEMENTS
COLLABORATING PARTNERS
Georgia Institute of Technology
London School of Hygiene and Tropical Medicine
Ministerio da Saude de Moçambique
University of Florida
University of North Carolina
Water and Sanitation for the Urban Poor
World Bank Water and Sanitation Programme
FUNDING & DISCLAIMER
This study was funded by the United States Agency for
International Development under Translating Research into
Action, Cooperative Agreement No. GHS‐A‐00‐09‐00015‐00.
This study is made possible by the support of the American
People through the Unites States Agency for International
Development (USAID). The findings of this study are the sole
responsibility of LSHTM and Georgia Tech and do not
necessarily reflect the views of USAID or the United States
Government.

50. Questions
• 1. Is it plausible to expect that onsite shared
sanitation is likely to result in lower exposure to
pathogens among children in these settings?
– Do these septic tanks work? Where is the leach
field?
• 2. Isn’t density likely co‐linear with poverty? So
how will we sort this out?
• 3. What about child feces disposal? The
intervention may not affect this.

51. More questions
• 4. Are the controls suitable? Are we selecting
for factors that may be related to exposures or
outcomes?
• 5. What if the primary outcome variable (and
STHs) are unaffected by the intervention?
– Particularly viruses?
– Poor effectiveness of single‐dose albendazole
• 6. How strongly associated are outcome
measures and population density?
– Will use baseline analysis

52. MapSan
• The first controlled health impact trial of an urban
de‐centralized (non‐sewerage) sanitation
intervention.
– Most common form of sanitation in urban areas
• The first sanitation health impact trial of shared
sanitation (760m+ users, mostly in SSA).
• The first sanitation health impact trial that uses a
direct measure of enteric infections as a primary
outcome measure.
– On causal chain for ALL downstream impacts, objective
• The first sanitation health impact trial that includes
a focus on localized population density.