Water
& Disease 2:
Diarrhoeal diseases
Diarrhoea itself is not a disease, rather (1)it is a
symptom of many diseases. Diseases that cause diarrhoea are the most
deadly, killing over two million people every year - mostly children
under the age of five. There are approximately four billion cases of
diarrhoea each year (2)which are caused
by more than 100 different bacteria, protozoa or viruses. (3)These are spread
through:
- Contaminated water
- Contaminated food
- (4)Unsanitary
disposal of human waste
- Poor personal hygiene
Diarrhoea causes the rapid
depletion of water and sodium in the sufferer. If (5)these are not
replaced quickly, the body starts to become (6)dehydrated and the
body's salt balance is severely damaged. If more than 10% of the body's
fluid is lost the sufferer dies. Children who are malnourished suffer
the most, becoming even weaker and more (7)malnourished as
diarrhoea progresses.
The three most deadly
diarrhoeal diseases are cholera, bacillary dysentery and typhoid.
Others include amoebic dysentry, giardiadis, salmonella,
camplyobacteriosis and cryptosporidiosis. All of (8)these diseases
can be stopped by the same preventative methods, so if the three most
deadly were eliminated (9)the others would
be too.
Cholera is a disease that can cause
large epidemics killing the young, the weak and the old. (10)It is known and
feared throughout the developing world. The bacteria, which can last
for up to three weeks in soil, is spread by contaminated water, food
and occasionally by person to person contact. Sudden large outbreaks
are usually caused by a contaminated water supply.
Effect on health: The bacteria
attaches to the wall of the small intestine where (11)it multiplies and
produces a poisonous chemical. This poison prevents the body from
taking water from the intestine and so the body rapidly (12)dehydrates. Up to
14 litres of diarrhoea can by passed in one day. The lack of water in
the body causes the blood pressure to drop and the kidneys to fail.
Death occurs within 24 hours.
Bacillary dysentery is more severe
than amoebic dysentery. (13)It is estimated
that 140 million people are infected each year resulting in around
300,000 deaths annually, mostly among children under the age of five. (14)It is caused by Shigella bacteria
which enter the body through contaminated drinking water, food or flies
which then infect the large intestine. It can be spread between people
- especially young children.
Effect on health: Symptoms can
include fever, abdominal pain, nausea, cramping and severe, frequent,
watery diarrhoea that can contain blood, mucus and pus.
Typhoid fever affects 17 million
people worldwide every year, with approximately 600,000 deaths. It is
contracted when people drink water or eat food infected with a
bacterium called Salmonella Typhi found in human waste. (15)It has been
virtually eliminated in the western world through sanitary facilities.
Effect on health: Typhoid fever is
recognised by the sudden onset of sustained fever, severe headache,
nausea and constipation. Later (16)it is accompanied
by diarrhoea, a rash and other complications (17)which can include
intestinal haemorrhaging or perforation.
Prevention
of diarrhoeal diseases
Diarrhoeal diseases can be
prevented by improving access to clean water and sanitation so that
bacteria cannot (17)re-enter
water supplies. Hygiene education plays a vital role in informing
communities about safe hygiene. The keys to prevention are clean water,
clean hands at meal times and (18)uncontaminated
food. Hygiene education where communities learn about the benefits of
using latrines, keeping food and water clean, cooking food thoroughly,
washing and peeling fruit and vegetables, washing hands with soap
before touching food and the sanitary disposal of human waste can all
help prevent diarrhoea and contamination.
Task 1: Pronoun
referents:
Read the passage above and decide what each of the words highlighted in
grey refers to.
Example: (1)it refers to
‘diarrhoea’.
1. What does
(2)which refer to?
2. What does
(3)These refer to?
3. What does
(5)these refer to?
4. What does
(8)these refer to?
5. What does
(9)the others refer to?
6. What does
(10)It refer to?
7. What does
(11)it refer to?
8. Does (13)It refer to a noun in the text?
9. What does
(14)It refer to?
10. What
does (15)it refer to?
11. What
does (16)it refer to?
12. What
does (17)which refer to?
Task
2, Word parts: Decide what each part of the words highlighted in grey
means.
Example: (4)Un means ‘not’.
What does (6) hydra in dehydrated mean?
What does (7)mal malnourished mean?
What does (12)de in dehydrates mean?
What does (17)re in re-enter mean?
What does (18)un in uncontaminated mean?
Task
3, Question Formation:
Make
up three questions based on the information in the passage. For
example: How many cases of diarrhoea are there each year?
Go
on to Water and Disease 3
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