Transcript Dr Jamie Bartram - The University of North Carolina at Chapel Hill

Water, Sanitation and Health:
the Millennium Development Goals
and Reducing the Global Burden of
Disease
Jamie Bartram
With adaptations by
Mark Sobsey, UNCChapel Hill
Overview


Water, poverty and prosperity
Water: a health concern?
• Disability adjusted life years (DALYs)



Who and where are the
disadvantaged?
Perspectives / trends
Why invest in water and sanitation?
Water, poverty and
prosperity
WSH = disease and poverty ?
• Inadequate water supply
• Time, financial cost
• Unsafe water resources
• Disease burden
• Inequitable access
• Health care costs
POVERTY
WSH = a motor for development
• Improved water supply
• Time, financial savings
• Safe water resources
• Averted disease costs
• Universal access
• Healthy populations
Development
Water: A health concern?
Leading Causes of Deaths from Infectious Diseases
2004 World Health Report
3963
2777
1798
1566
1271
611
R
es
pi
ra
to
ry
In
fe
ct
io
ns
D
H
ia
IV
rrh
/A
oe
ID
al
S
D
is
ea
Tu
se
s
be
rc
ul
os
is
M
al
ar
ia
M
ea
sl
es
Deaths (000s)
4500
4000
3500
3000
2500
2000
1500
1000
500
0
Non-fatal health effects
 Mortality numbers can dominate
conversations about health
 Also concerned about non-fatal health
conditions
 A metric was needed to quantify non-fatal
health outcomes, make informed policy
decisions and allocate health resources
 WHO introduced Disability Adjusted Life
Years (DALYs) in 1994
 Used to assess risks and benefits
associated with various diseases, threats to
health and interventions
Disability Adjusted Life Years

DALY = YLL + YLD
• YLL – years of life lost due to early death
• YLD – years of life lost to disability

YLL = N x L
• N = number of deaths
• L = standard life expectancy at age of death in
years

YLD = I x DW x L
• I = number of incident cases
• DW = disability weight
• L = average duration of the case until
remission or death (years)
DALY – Example Disability Weights
Weight
Disease/stage
0.00-0.01
Gingivitis, caries
0.01-0.05
Mild asthma, mild vision loss, mild hearing loss, basal cell skin cancer
0.05-0.10
Low back pain, uncomplicated diabetes case, mild angina
0.10-0.15
Mild depression, osteoarthritis (grade 2), epilepsy
0.15-0.20
Mild/mod. panic disorder, spina bifida (sacral), HIV positive
0.20-0.30
Breast cancer (disease free), anorexia, mild/mod. obsessive- compulsive disorder
0.30-0.40
Moderate depression, relapsing MS, severe asthma, chronic Hep B, deafness
0.40-0.50
Blindness, spina bifida (L3-L5), osteoarthritis (grade 3-4)
0.50-0.65
Paraplegia, AIDS (1st stage), Down syndrome, severe PTSD
0.65-0.8
Cancer (diagnostic/treatment), severe depression, brain injury
0.8-1.0
Disseminated cancer, severe dementia, severe schizophrenia, quadriplegia
1
Stouthard MEA, Essink-Bot ML, Bonsel GJ, Barendregt JJ, Kramer PG, van de Water HPA, GunningSchepers LJ, van der Maas PJ (1997). Disability Weights for Diseases in the Netherlands. Rotterdam:
DALY – Graphical Example
Disability weight
1
0.8
0.6
Acute
(infectious)
disease
0.4
0.2
Premature
death
0
0
20
40
60
Age Residual
disability
80
How much disease could be prevented
by modifying the environment?
Prüss-Ustün and Corvalán (2007) How Much Disease Burden can be Prevented by Environmental Interventions?,
Epidemiology, 18:1, p. 167-178.
Reduction (%)
Diarrhoeal disease reduction from drinking
water and sanitation improvements
Source: Fewtrell L et al. Water,
sanitation, and hygiene
interventions to reduce
diarrhoea in less developed
countries: a systematic review
and meta-analysis.Lancet
Infectious Diseases, 2005
Intervention
GBD – Selected water-related diseases
• Diarrhoea:
1.8 million people, mostly children, die of diarrhoea every year
Malaria:
1 million people, mostly children, die of malaria every year
Better management of water resources reduces transmission
• Schistosomiasis:
200 million are infected, 20 million suffer severe consequences
Basic sanitation reduces the diseases by up to 77%
• Trachoma
6 million visually impaired, 146 million threatened by blindness
Improved sanitary conditions and hygiene practices prevents
trachoma
The more we know, the more
environment matters
In addition (2010?)
Total disease
2005
5%
4%
3%
2002
WSH caused
diarrhoea and
parasitic diseases
Water hardness and heart
disease, hepatitis A and E,
fluorosis, arsenicosis,
typhoid fever etc.
Also WSH-caused
malnutrition
?
Who and where are the
disadvantaged?
Improved Drinking Water:
Status in 2002
Coverage of improved drinking water sources, 2002
Percentage of population
using improved drinking water sources
Less than 50%
50 - 75%
76 - 90%
91 - 100%
missing data
Meeting the MDG Drinking Water and Sanitation Target: Mid-term
Assessment of Progress
WHO and UNICEF, 2004
WHO/OMS
Improved Sanitation:
Status in 2002
Sanitation coverage, 2002
Percentage of population
using improved sanitation
Less than 50%
50 - 75%
76 - 90%
91 - 100%
missing data
Meeting the MDG Drinking Water and Sanitation Target: Mid-term
Assessment of Progress
WHO and UNICEF, 2004
WHO/OMS
Improved Sanitation:
Unserved population by region, 2002 (millions)
Meeting the
MDG
Drinking
Water and
Sanitation
Target:
Mid-term
Assessment
of Progress
WHO and
UNICEF,
2004
Disparities Masked by National Averages:
Rural versus urban sanitation (2002)
Meeting the
MDG
Drinking
Water and
Sanitation
Target:
Mid-term
Assessment
of Progress
WHO and
UNICEF,
2004
Perspectives / trends
Reaching the MD Goals from 2002:
What does it mean for Goal 7 Target 10?
To halve, between 1990 and 2015, the proportion of the
population without improved drinking water and sanitation
now means means:
Enabling an additional
260,000 people a day up
to 2015 to use improved
drinking water sources
Enabling an
additional 370,000
people a day up to
2015 to use improved
sanitation
Ensuring continuation of services to an unprecedented
population and maintenance and renewal of infrastructure
Reaching the MD Goals from 2002:
Focusing G7 T10 on the wider goals
Reaching the target would:
• Reduce disease and death
•Improve nutrition and food
security
• Reduce poverty (avert health
care costs, time savings)
Unserved, children and
women likely to benefit
most (health and education)
Studies show WS&S to be
cost effective
Improved Drinking Water:
Trends in service levels
Un-served
Other 'improved drinking water source'
Piped water at home
Meeting the
MDG
Drinking
Water and
Sanitation
Target:
Mid-term
Assessment
of Progress
WHO and
UNICEF,
2004
Improved Sanitation:
Perspectives
Population (in billions)
3,0
2.7 bn
2,5
2.4 bn
2,0
1.9 bn
1,5
1,0
0,5
0,0
1990
2002
2015
If on track to reach the MDG target
Current trend
Meeting the
MDG
Drinking
Water and
Sanitation
Target:
Mid-term
Assessment
of Progress
WHO and
UNICEF,
2004
Population change 1990-2030
9
8
7.5
Population (billions)
7.2
7
5.7
6
6.1
6.5
7.9
6.8
5.3
4.9
5
3.5
4
3
3.1
3.2
3.3
2.9
3.2
3
2.3
2
8.1
2.6
3.3
3.9
3.3
4.2
3.3
4.6
3.3
3.2
1
0
1990
95
00
05
10
15
20
25
30
Year
Change 1990-2002
Change 1990-2015
Global: 18%
Global: 37%
Urban: 31%
Urban: 70%
Rural: 8%
Rural: 12%
Global population
Urban population
Rural population
Reaching the MD Goals from 2002:
Focusing G7 T10 on the wider goals
Reaching the target would:
• Reduce disease and death
•Improve nutrition and food
security
• Reduce poverty (avert health
care costs, time savings)
1 billion urban dwellers to
keep up with urban
population growth –
targetting slums
Unserved, children and
women likely to benefit
most (health and education)
Studies show WS&S to be
cost effective
900 million rural dwellers
to start to deal with the
rural backlog
Why invest in water and
sanitation?
Introduction of Municipal Water
Treatment in the United States
Introduction of Municipal Water
Treatment in the United States
Annual cost of not dealing with
water and sanitation
Lives lost
 1.8 million annually due to diarrhoea
alone
Health care costs:
 USD7 billion per year to health
agencies
 USD340 million to individuals
Value of time lost
 USD 63 billion per year
Cost-benefit analysis (CBA)
The aim of the study was to estimate:



the costs (capital and recurrent)
the health benefits (diarrhoea cases and deaths)
the additional benefits (costs averted, time saved)

Results presented as US$ per year, per
capita , per intervention.

Note that these methods are highly dependent upon
assumptions and that there are numerous data gaps
Interventions

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5 interventions were modelled:
Halving population w/o improved WS by 2015 (through
low-tech services).
Halving population w/o improved WS&S by 2015
(through low-tech services) (MDG 7).
Increasing access to improved WS&S services (lowtech) for all by 2015.
Increasing access to improved WS&S services (lowtech) plus disinfection at point of use, for all by 2015.
Increasing access to in-house piped water and sewer
connection for all by 2015.
Cost-effectiveness ratios (US$
per DALY averted)
900
800
Disinfection
700
Halve pop w/o
access to WS
600
500
Halve pop w/o
access to WS&S
400
300
Improved water
supply and basic
sanitation
200
100
-
AFRO D
AFRO E
AMRO D
EMRO D
SEARO D
Piped water
supply and sewer
connection
Macro relevance?



High malaria versus low malaria
countries: 1% difference in annual
GDP growth
Cholera in Latin America in 1990’s
3.7% average annual growth by
poor countries with improved W&S
(as opposed to 0.1% for those
without)
Suggested Reading:
Pruss-Ustun, A. and C. Corvalan (2007) How much
disease burden can be prevented by environmental
interventions? Epidemiology. 18(1):167-78.
Further Topic Details at:
www.who.int/water_sanitation_health/