Unit 7 - WASH, water & sanitation

Ignaz Semmelweiss observed what at Vienna General Hospital?

- 2% mortality rate for puerperal fever in midwives ward - 18.3% mort rate in the med students ward

Main zoonotic enteric pathogens

- Bacteria: Campylobacter, E. coli (STEC), nontyphoidal Salmonella - Protoza: Cyrpto, Giardia - Viruses: rotavirus, norovirus

what is sanitation and what are its 5 components?

- Defined: safe removal of human excreta - capture, storage, transport, treatment, reuse

Ecuador microbe results

- children: Giardia, Campylobacter, aEPEC (atypical EPEC) - chickens, guinea pigs, pigs dogs: campylobacter primarily

Env Enteric Dysfunction study findings

- generally asymptomatic for diarrhea (diarrhea observed 7% of the time - infants exp stunting had enteropathy 75% of the time

Study on children's exposure studied and concluded what?

- observed children in their env and sampled everything children put in their mouths - conclu: children should be protected from exploratory ingestion of chicken feces

sanitation facilities not considered improved by UN standards

- public/shared by more than one household

STHs = what and aka what?

- soil-transmitted helminths aka geohelminths

What 3 things do NOT fall under sanitation?

- solid waste (trash) - food safety - home/workplace cleanliness

Small scale livestock affects how many ppl and where?

1 billion, and in small + middle income countries

common indicators used for hand washing

1. % who know all critical moments for HW (question) 2. % of households w/soap & water at HW station commonly used by fam (obs) 3. % households w/soap & water at HW station inside or w/in 10 paces of latrine (obs) 4. % households w/soap or locally avail cleaning agent for HW anywhere in household 5. vol of lac-based hand gel consume on per-pt basis (usually in health care facility only)

3 different meta studies about hand washing & diarrhea

1. Curtis & Cairncross, 2003: 10 studies, estimated 47% redux 2. Fewtrell et al 2005: 11 studies, 44% redux 3. Ejemot et al 2007: 5 comm-based studies in low-inc countries, 31% redux

Ecuador microbiological methods

1. Direct plating methods and biochem tests 2. PCR 3. Multilocus sequence typing

examples of improved sanitation

1. Flush toilet 2. Connection to a piped sewer system 3. Connection to a septic system 4. Flush / pour-flush to a pit latrine 5. Pit latrine with slab 6. Ventilated improved pit latrine (abbreviated as VIP latrine) 7. Composting toilet

contextual factors for HW

1. HW w/soap requires money, time, water & space 2. ppl who would benefit most are often least educated & have lowest income 3. using soap is not cultural habit

4 avg measures of HWWS across 11 countries

1. HWWS after toilet: 17% 2. HWWS after cleaning child: 13% 3. HWWS after cleaning up child stools: 19% 4. HWWS before feeding child: 5%

4 leading pathogens causing diarrhea & diarrheal-realted death

1. Rotavirus 2. Cryptosporidium 3. pathogenic E. coli 4. Shigella

top 3 enteric pathogens causing diarrhea in 0-11 month old children

1. Rotavirus 2. cryptosporidium 3. shigella-toxin E. coli

Top 3 pathogens causing most deaths

1. ST-ETEC 2. tEPEC 3. Cryptosporidum

6 Factors in deciding on appropriate sanitation solutions

1. affordable 2. available 3. culturally acceptable 4. easy to use & maintain 5. sufficient capacity for O & M 6. environmentally sound

6 main WHO-approved household water treatment options

1. chlorination safe water system (SWS) 2. combined flocculent/disinfx 3. ceramic filtration 4. biosand filtration 5. solar/SODIS 6. Boiling

In addition to death, malnutrition can also lead to what in children?

1. cognitive impairment 2. decreased wages 3. increased chronic diseases

examples of unimproved sanitation

1. hanging toilets (waste goes nowhere) 2. public toilet (tragedy of commons) 3. pit latrine with no cleanable surface 4. Flush/pour flush to elsewhere (not into a pit, septic tank, or sewer) 5. Pit latrine without slab 6. Bucket latrines 7. No facilities / bush / field (open defecation)

more barriers to improved handwashing

1. little perceived benefit (mostly I'm fine/not sick without HW) 2. not linked to cultural concepts of purity, good mothering, sexual attraction 3. is not seen as a habit

top 3 enteric pathogens causing diarrhea in 12-23 month old children

1. rotavirus 2. shigella spp 3. cryptosporidium

most pathologically important helminths and how many ppl do they impact?

1. roundworms - 1.2 billion 2. whipworms - 800 million 3. hookworms - 740 million

3 main protective barriers to the fecal-oral route:

1. sanitation (fluids, flies, fields/floors) 2. clean water supply (food) 3. hygiene/hand-washing (fingers, flies, fields/floors)

top 3 enteric pathogens causing diarrhea in 24-59 month old children

1. shigella sp 2. rotavirus 3. Campylobacter jejuni

Env Enteric dysfunction is thought to cause what?

1. stunting 2. malnutrition 3. oral fax failure 4. impaired cognitive development

malnutrition is underlying cause of approx how many child deaths annually?

1.5 million

approx how many cases of severe diarrhea throughout the world each day?

100,000

Chlorine started to be used in drinking water in Philly when? And what endemic infx was tracked as declining in conjunction with?

1914 - typhoid

safe water storage results in approx what % redux in diarrhea

21%

sanitation results in approx what % redux in diarrhea

30%

point of use water treatment results in approx what % redux in diarrhea

30-50% (2x as effective as interventions that improve water quality at the source)

wand washing with soap results in approx what % redux in diarrhea

43%

approx redux in roundworm, whipworm, hookworm with improved sanitation

46%, 42%, 40%

Ecuador study overview

480 households 6 zoonotic enterpathogens children <5 yrs old household animal species households w/no animals vs households w/animals

effect of sewerage on diarrhea

59% redux

child age of greatest # of diarrheal episodes per day across all age-groups

6-11 months, followed by 1 year

Ecuador summary

Campylobacter jejuni & atypical EPEC likely transmitted from domestic animals to children --> aEPEC: pigs, chix, dogs --> C. jejuni: chix, guinea pigs, rabbits, dogs

Ecuador sequence typing results

Campylobacter sequence types found in both children and many of the animals, chickens primarily

main question to consider with hygiene interventions

Can improvements be sustained?

T/F Only severe diarrhea can effect children's nutrition and growth

F - even moderate diarrhea can

Fecal-oral route of disease - F-diagram

Feces --> fluids, fingers, flies, fields/floors --> food --> child

Direct effect WASH has on nutrition

Frequent or chronic diarrheal episodes result in deviation from weight-for-age normal curve

Ecuador study: most prevalent pathogen in children

Giardia (34.4%), also in dogs, rabbits, pigs, guinea pigs, sheep

MDG tasked with safe drinking water and basic sanitation

Goal 7: Target 7C: halve by 2015 proportion of ppl without access to safe drinking water and basic sanitation

Semmelweiss' study

Had med students wash hands with chlorinated lime after studying cadavers, puerperal fever mort dropped to about 2% - i.e. hand washing saves lives

HWWS

Hand washing with soap

Ecuador study survey instruments

Household survey: - demographic info - WASH - SES - Child-animal infx - medication use - health status Animal mgmt survey Fecal sample collection

A child is considered stunted when?

If they are more than 2 standard deviations below the mean height for age z-score

Sandy Cairncross quote

Lots of people without toilets and lots of toilets without people

Which MDG targets were met, which were not?

Met: global MDG water target Unmet: global MDG sanitation target

Environmental Enteric Dysfunction

Microbes that enter and take up residence in the gut as a result of poor sanitation conditions results in physiological dysfunction of the gut - intestinal inflammation without overt diarrhea - acquired early in childhood

2015 MDG target for sanitation - hit or missed?

Missed by 700 million

STHs affect approx how many ppl?

Over 1 billion

ST-ETEC

Shigella-toxin producing enterotoxigenic E. coli

SDG relating to sanitation goals and by when?

Target 6.2: by 2030 achieve adequate and equitable sanitation and hygiene for all, end open defecation, paying special attention to needs of women and girls

Study re: positive impact of livestock ownership found what?

Tenfold increase in household livestock ownership had significant association with lower stunting prevalence in 2 of 3 countries

Purpose of mulitlocus sequence typing

To assess relatedness/strains of pathogens

T/F: EED is a reversible/resolvable condition

True: resolves with migration to high income countries; also shown to occur in Peace Corps volunteers and resolve within 12 months

WASH

WAter, Sanitation, Hygiene

what animal has been ID'ed as a primary culprit for spreading diarrheal disease?

chickens

tragedy of commons

concept that applies when a public utility/resource isn't good for anyone because no one takes care of it

EPEC

enteropathogenic E. coli

Other health outcomes effected by WASH

hepatitis A, E, F legionellosis scabies arsenicosis fluorosis

what is the main indicator/marker of malnutrition and how is it measured?

stunting: measured by comparing a child's height for age to a reference group

3 main ways water can become contaminated

transport handling storage

risk factors of animal excreta contamination are primarily related to what?

water