Aetiologyand Basis of Water Borne
Disease
Dr. AnujSingh
Asst. Professor
Community Medicine
UIMS, Prayagraj
Facts:Availability of water
• About 97 per cent of earth’s water, unfit for
human consumption.
• Of the remaining 3 per cent, 2.3 per cent is
locked in the polar ice caps and glacier.
• The balance 0.7 per cent is available as
freshwater.
•More than 3.4 million people die each
year from water, sanitation, and
hygiene-related causes. Nearly all
deaths, 99 percent, occur in the
developing world.
•According to WHO, diarrhoea alone
claims the lives of 1.8 million people
every year.
•About 12 millions people get infected by
typhoid every year.
• 780 million people lack access to an
improved water source; approximately
one in nine people.
• More people have a mobile phone than a
toilet
Water-borne Diseases
High Incidence of Morbidity &
Mortality-developing Countries
Environmental
Unsafe water supply
Poor personal hygiene practice
Insanitory environment
Poor housing
Insects and rodents
Much of ill-health in developing
countries is due to lack of safe and
wholesome water supply
There can be no state of positive
health & wellbeing without safe water
Role in socio-economic development
of human population
Unsafe water supply
The Problem
~80% of infectious diseases
> 5 million people die each year
> 2 million die from water-related
diarrhea alone
Most of those dying are small
children
Other Consequences
Lost work days
Missed educational opportunities
Official and unofficial healthcare
costs
Draining of family resources
Natural
Man made
Water Pollution
Water Pollution-Natural
Dissolved gases
Dissolved minerals
Water Pollution-Natural
Not essentially dangerous
Derived from:
atmosphere
soil
catchment area
Dangerous
derived from:
human activity (open field
defecation)
urbanization
industrialization
Water Pollution-Man made
Water Pollution-Man made
Sewage: decomposable organic matter
and pathogenic agents
Industrial & trade wastes: toxic
agents and complex chemicals
Agricultural pollutants: fertilizers
and pesticides
Physical pollutants: heat & radio
active substances
Indicators Of Pollution
Biochemical oxygen demand (BOD) at
20 degree centigrade
Con.of chlorides, nitrogen,
phosphorous
Absence of dissolved oxygen
Diseases Related to
Water
Water-borne
Diseases
Inadequate
Water-
Diseases
Water-based
Diseases
Water-related
Diseases
Water-borne diseases
•Diseases caused by ingestion of
water contaminated by human or
animal excrement, which contain
pathogenic microorganisms.
•i.e. diarrhoea, cholera, typhoid
and gastro-enteritis etc.
Water borne
diseases
Water borne
diseases dir to
Infective agent
Water borne
diseases due to
Aquatic host
Due To Presence Of Infective Agent
Bacterial:cholera, typhoid, amoebic and
bacillary dysentery and other diarrheal
diseases
Viral:viral hepatitis A, hepatitis E,
poliomyelitis, rotavirus,
Protozoal:amoebiasis, giardiasis
Helminthic:round worm, thread worm,
hydatidosis
Leptospiral:weil’s disease
Due to Presence of Aquatic
Host
Diseases caused by parasites found in
intermediate organisms living in
contaminated water
Snail:Schistosomiasis
Cyclops:Dracunculosis, Fish tape
worm
Pollution of Water
With Chemicals
Arsenic
Flouride
Nitrates from fertilizers
Carcinogenic pesticides (DDT)
Lead (from pipes)
Heavy Metals
Diseases-due to
Inadequate Water
Diseases caused by poor personal
hygiene and skin and eye contact with
contaminated water.
These includescabies, trachoma,
typhus, and other flea, liceand tick-
borne diseases.
Water-related Diseases
Water-related diseases are caused
by insect vectors, especially
mosquitoes, that breed or feed near
contaminated water and not due to
lack of access to clean water or
sanitation services, e.g. malaria,
filaria, dengue, yellow fever etc.,
Other Water-borne
diseases
Bathing
Swimming
Other recreational activities that
have water contact
Agriculture
Aquaculture
DIARRHOEA
Control & Prevention
Global
Governments
Communities
Individuals
Global Surveillance
Public health infrastucture
Standardized surveillance of water-
borne disease outbreaks
Guidelines must be established for
investigating and reporting water-
borne diseases
Education Issues
Hygiene education
Good nutrition
Improvements in habitation and
general sanitation
Higher education training in water-
related issues
Communication and the
Media
Impacts at all levels
Very powerful, when other methods
fail
General Guidelines
Avoid contacting soil that may be
contaminated with human feces.
Do not defecate outdoors.
Dispose of diapers properly.
General Guidelines-cont.,
Wash hands with soap and water
before handling food.
When traveling to countries where
sanitation and hygiene are poor, avoid
water or food that may be
contaminated.
Wash, peel or cook all raw vegetables
and fruits before eating.
The Future
Even if by the year 2015 the
proportion of people who are unable
to reach or to afford safe drinking
water is halved, 76 million people,
mostly children, will die from
preventable water-borne diseases.