HSERVEpi 531

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HSERV/Epi 531 Nov 2007 WATER SANITATION

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Water sanitationLecture summary

• Historical context
• Impact of water sanitation on health
• Cost effectiveness of interventions
• Barriers to progress

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Water facts2007

• 1.1B lack safe and affordable water
• 2.4B lack adequate sanitation

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Historical role of water sanitation

• improved health conditions in 19th century USA
  and Europe - France example
• water/san were integral parts of the package of
  PHC and HFA2000
• 1981 declared decade for IDWSSD
• (Int Drinking Water Supply and Sanitation) UNDP
  with WHO, UNICEF, World Bank, UNDTCD
• "safe water for all"
• estimated costs 300B initial good response

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Mortality Declines in urban France in the 19th
Century (Preston, an de Walle)
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Child Survival and water/sanitation

• Ideology of "cost-effectiveness
• ORT -200-250/death averted 
• Water- 4000 child death averted Thus, Water,
  sanitation OK for Thailand, not for Bangladesh
• USAID funding water/san not included among
  programs that could be funded
• Implications  - water, sanitation measures vs CS
  IDWSSD was "dead"....funding began drying up,
  progress toward water/san slowed -by 1997
  2.1B/yr

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http//www.childinfo.org/eddb/water/printmap.htm
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Drinking water coverage 1990 2000
An additional phenomena, the lack of growth in
drinking water coverage in the urban areas of
developing
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Sanitation coverage by region, 1990 2000
Table 1 Sanitation coverage by region, 1990-2000
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http//www.childinfo.org/eddb/sani/trend.htm
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Impact of water and sanitation on health

• Reduction of infectious diseases - mechanisms
• Water-borne
• Water-washed
• Water-based
• Water-related
• Sanitation effect
• Age specific impact
• Time energy savings
• Multiplier effect
• cost

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Mechanisms of water and disease

• Water-borne pathogen in water, then ingested
• low dose cholera, typhoid
• high dose shigella, hepatitis ALL CAN BE
  TRANSMITTED BY ANY ROUTE WHICH ALLOWS INGESTION
  OF FECES
• Water washed
• pathogens reduced by water-dependent hygiene
  quantity rather than quality is critical
• contaminants in food, gardens, yards, hands,
  flies, utensils, plates, home envirnonment, a)
  GI cholera, shigella -  also water borne b)
  SKIN-EYES skin sepsis, scabies, fungi, trachoma
  - never water borne c) VECTORS-borne fleas,
  ticks, mites, lice,

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Mechanisms of water and disease (2)

• Water-based pathogen spends part of life in
  water examples schisto, guinea worm
• Water-related insect vector breed or bite near
  water examples malaria, yellow fever, dengue,
  onchocerciasis (breed in water) Trypanosomiasis
  (bites near water) (Gambian)

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Example of DIARRHEA

• major disease affected by water/san tends to be
  indicator multiple etiology severity depends on
  dose, nutrition, hydration
• Assumption reduction of ingestion of
  contaminants with water/sanitation reduces MM
  (especially diarrhea)

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Pathogens and diarrhea

• morbidity, mortality dose - related (hypothetical
  graph)
• impact also depends on age, BF, Education, ORT
  use, measurement of Diarrhea
• Multiple routes of transmission (slide)

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Dose-response of pathogens related to incidence
of diarrhea in children
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Multiple routes of transmission of disease from
feces
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Age specific impact in diarrhea - quality vs
quantity of water

• under 1 yr  quality quantity
• exclusive breast feeding little else ingested
  in first 6 months
• child under one eats the world (washing)
• 1-5 yrs quantity
• kids are walking, mobile, multiple sources of
  liquids, play in puddles     THUS, LESS
  SUSCEPTIBLE TO QUALITY but relatively more
  susceptible to quantity (washing), which can
  decrease microbes from hands, face, utensils,
  plates, and reduce flies

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Age specific impact in sanitation

• WHO USES LATRINES?
• disposal of feces toilets, latrines should
  reduce fecal contamination in kids, biggest
  transmitters
• problem of smell, dirty, inadequate Hed (improved
  with VIP?)
• 0-2 don't use latrines much - fear-  but have
  the greatest prevalence of diarrhea
• 2-5 hard to use

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Time-energy-money savings

• time
• release for kids, women - helps do other tasks (H
  education, H care) 2-5 hrs/day
• money
• poor spend 30 income on water, rich lt2
• Poor in urban areas buy from vendors at 3X price
  (Lima)

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Multiplier effect

• prevents more diseases
• improves health services (water-san in health
  posts, hospitals)
• improves nutrition (clean food, breasts)
• improves health education (principal resource
  needed for Hed)
• time, energy released for women, kids
• irrigation, animal watering
• comercial activity stimulus (resturants,industries
  )
• quality of life (esp for poor)

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HOW DOES THE IMPACT OF WATER AND SANITATION
COMPARE WITH OTHER INTERVENTIONS

• probably effective water,san/ BF, weaning,
  Immunizations, personal hygiene
• uncertain LBW, Growth charts, child spacing, Vit
  A, food hygiene, zoonotic control, epi control
• Feachem R - BWHO, 61(4), 637-40, 1983

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Comparative interventions for diarrhea control
(Feachem 1983)
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COST

• General not easily compared to other
  interventions need to include capital,
  operations/maintenance, overhead,health
  education, mobilization estimate - 30 of costs
  are annual recurrent costs
• to individual households borehole in Nigeria
  15,000 in 1980 4000 in 1990 avg initial per
  cap investment of 30/maint _at_ 1/yr boiling
  water (10 min) Bangladesh poorest 25-22
  annual income on fuel highest 10 food and fuel
  alone 104
• to society resource allocation/distributive
  equity CHART 10/yr water - 4/yr sanitation

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COMPARING COST-EFFECTIVENESS

• Difficult
• different costing in different countries,
  assumptions
• multiple vs single benefits
• water/san also reduces diarrhea in adults,
• reduces other ID more time, less caloric
  espenditure

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Obstacles to progress

• Funding national and international
• not enough (current 2.1B/yr need 7B/yr)
• misplaced
•  Organizational structure capacity in THird World
  
• interministerial collaboration bureaucratic
  jealosy
• water engineers in MOH low prestige compared to
  clinicians
• Urban vs. rural focus
• Local technical expertise
• Togo 1 rural water agent for 300 villages
• Zaire lt10 in country
• Burundi only employee of water services was
  director
• Overall Africa 1-2 san/100,000 in 30 countries
  (1980-WHO)
•  Maintenance   -studies maintanence better if
  done by women

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SUMMARY/CONCLUSION

• clean water has been made available for 700
  million - safe water for all" not achieved
• sanitation to 480 million - mostly in China,
  India, Pakistan
• Water is cheaper today- per capita cost 1/30 of
  1970 level Asia 1-2/yr Africa/LA 5/yr
  
• 10B is currently invested/yr 80 devoted to
  services to rich _at_ 600/capita less than 20 to
  projects less than 30/cap
• community involvement is key in planning, siting,
  constructing, installing, maintaining

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http//www.arts.mcgill.ca/152-497b/h2o/water/gwate
r/death.htm
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Water Related Diseases in poor countries (000s)
http//www.arts.mcgill.ca/152-497b/h2o/water/gwate
r/death.htm
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Proportion of Preventable Water Related Diseases
in East Africa
http//www.arts.mcgill.ca/152-497b/h2o/water/gwate
r/death.htm
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ESTIMATES OF MORBIDITY AND MORTALITY OF
WATER-RELATED DISEASES
1 People currently infected. 2 Excluding
Sudan. 3 Case of the active disease.
Approximately 5,900,000 cases of blindness or
severe complications of Trachoma occur
annually. 4 Includes an estimated 270,000
blind. 5 Mortality caused by blindness. Source
WHO data
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http//www.who.int/water_sanitation_health/Globass
essment/Global2.1.htm
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