DIARRHEAL DISEASES

Top Ten Causes of Deaths in Low-Income Countries

http://www.who.int/mediacentre/factsheets/fs310/en/index.html

Top Ten Causes of Deaths World-Wide

http://www.who.int/mediacentre/factsheets/fs310/en/index.html

Importance of DiarrheaAccording to the World Health Organization, the incidence of diarrheal diseases (2,533 million cases) topped all other diseases in the Southeast Asian (SEARO) and Western Pacific (WPRO) regions in 2004, accounting for 72.8 million disability-adjusted life years(DALYS) - 4.8% of all DALYS worldwide due to both infectious and non-infectious diseases

Importance of Diarrheal DiseasesAccording to the World Health Organization in 2005,

1.8 million people died of diarrheal diseases, nearly 70% of whom were young children

Worldwide, diarrheal diseases are the third leading cause of mortality and morbidity (exceeded only by lower respiratory infections and cardiovascular diseases)

Globally there were 1.7 billion cases of diarrhea in 2013

Diarrhea is a leading cause of malnutrition in children younger than 5 years

WATERTRUMPS

OIL

World Water Day event focuses on growing thirst. National Geographic 2010

"Next to oxygen, water is indisputably the most precious resource we have, and the shortage of

freshwater is the biggest long-term problem facing the planet Earth. Even energy is a distant second--with energy, we have alternatives. With water there are

none."

Gil Grosvenor, chairman of the National Geographic Society

The burden of thirst. National Geographic 2010

The burden of thirst. National Geographic 2010

Water Sources and Usage

Nearly 97% of the planet's water is salt waterin seas and oceans

Close to 2% of Earth's water is frozen in polarice sheets and glaciers

Only a fraction of 1% is available for drinking,irrigation, and industrial use

Agriculture accounts for 70% of all water use

Lack of Clean Water and Safe Waste Disposal

The average American uses a hundred gallons of water at home every day

In developing countries, nearly one billion people worldwide have no access to clean water

2.5 billion people (40% of world’s population) have no safe way to dispose of human waste

Dirty Water and Lack of HygieneDirty Water and Lack of Hygiene

Dirty water and lack of a toilet and proper hygiene kill 3.3 million people around the world annually, most of

them children under age five

Reasons for Lack of Clean Water Climate (drought, deforestation, climate

changes) and dropping water tables worldwide(unsustainable rate of water use)

Poverty (inability to build wells or to affordpiped water or water purification tablets ifavailable)

Rural dwellers- remote, sparsely populated,drought-stricken villages of the world are leastlikely to be reached for water provision,education, etc.Pollution

Clasen T, Sugden S. Water and sanitation. Oxford Textbook of Public Health, 5th ed. Oxford Press, England.

Steps to Reduce Waterborne Diseases

• Safe disposal of human waste (latrines)

• Hand washing

• Education about sanitation

• Piped, treated water

• Food safety

Politics of Water

The United Nation's General Assembly voted to make water a basic human right. But 41

countries, including the United States, opted out, saying they were waiting for more data!

Characteristics of Diarrheal DiseasesOral-fecal route of infection (contaminated water

and food)

Leads to rapid dehydration and inability to absorb nutrients from food; survivors may have impaired growth and development, malnutrition, long-term GI disorders, reduced immunity

Diarrhea IncidenceDiarrhea Incidence

COMMON CAUSES OF DIARRHEA (1) Bacteria

• Escherichia coli• Salmonella (S. typhii, etc.)• Shigella (S. flexinari , dysenteria, sonnei,

etc.)• Campylobacter• Vibrio cholerae

COMMON CAUSES OF DIARRHEA (2) Viruses

• Rotavirus

Protozoa• Giardia lamblia• Cryptosporidium parvum• Entamoeba histolytica• Cyclospora cayetanensis

IMPACT OF DIARRHEAL AGENTS ON GUT

Directly pathogenic organism

Production of toxin by specific organisms

Disruption of gut mucosa and gut function

Overcome commensal (good) gut organisms

Inflammation of gut mucosa

TRANSMISSION ROUTESDirect: fecal-oralIndirect:Water (e.g. V. cholerae, Norwalk virus)Food (e.g., salmonella, campylobacter, E. coli, O157:H7)Eating utensils (e.g., baby bottles, nipples, cups, spoons)Animals (e.g., C. jejuni, C. perfringens, E. coli, O157:H7)Flies (carrier, ingested – Shigella)Poor hygiene (inadequate/infrequent hand washing and non-hygienic feces disposal

Promiscuous drug use – overtreatment of humans and antibiotics in animal feed promotes drug resistance

HOST RISK FACTORS FOR DIARRHEA Malnutrition (up to 70% increased risk) Micronutrient deficiency (e.g. vitamin A and

zinc) Low gastric acid/hypochlorhydria (H. pylori) Reduced gastric acid acidity (e.g. associated

with some medications) Compromised cell-mediated immune

capacity/response Genetic profile (e.g., blood group O increases

susceptibility to V. cholerae)

COMMUNITY STRATEGIES TO REDUCE DIARRHEA

Promotion of breast feeding and better weaning practices

Safe water provision and waste disposal Promotion of hand washing Measles vaccination Cholera vaccination in high risk areas Zinc and vitamin A supplementation Rotavirus vaccination: Rota Teq,

Rotarix

Prevention of Diarrheal DiseasesProvision of accessible clean waterSafe disposal of waste (sanitation)Education of mothersMaking home treatment and storage of water

inexpensive and feasibleProvision of latrinesPromotion of hand-washing and personal hygieneReduce fly populationPromotion of breastfeeding and proper weaningPOLITICAL WILLMONEY

TREATMENT OF ACUTE DIARRHEATREATMENT OF ACUTE DIARRHEA

Oral rehydration Appropriate energy (food) intake Zinc supplementation for 10-14 days Referral to health facility if not

improving on above regimen Antibiotics (dysentery, typhoid fever,

cholera only) Intravenous saline (severe cases only)