Transcript 12.1.1 Non-infectious Diseasex

A Search For Better Health
Topic 11: Epidemiology
Biology in Focus, HSC Course
DOT Point(s)
identify causes of non-infectious disease using an
example from each of the following categories:
•inherited diseases
•nutritional deficiencies
•environmental diseases
Introduction
Non-infectious diseases are those diseases that are not caused by a
pathogen and are not contagious. There is a huge range of noninfectious diseases and their causes are many and varied.
web2.newtown-h.schools.nsw.edu.au
Introduction
Historically, infectious diseases
were the main cause of death in
the world and, indeed, in some
developing regions this may still
be the case. With the
development of antibiotics and
vaccination programs, infectious
disease is no longer the leading
cause of death in the Western
world.
www.amta.org.au
Introduction
 Non-infectious disease is now
responsible for the leading
causes of death in both
developed and some
developing countries.
This table shows that the leading
causes of death in Australia in
2009 are all non-infectious
diseases. Cancer is the leading
cause of death.
www.couriermail.com.au
Introduction
Non-infectious disease includes
inherited diseases caused by changes
in genetic information, nutritional
deficiencies caused by an inadequate
diet, and environmental diseases that
are the result of factors in the
environment. Other diseases such as
those caused by some types of
physiological malfunction, some
mental illnesses and ageing will not
fit into these categories.
window20.com
Inherited Diseases
These are diseases that are
genetically transmitted and are
caused by errors in genetic
information.
These errors may include:
 a change in the chromosome
numbers. For example, Down
syndrome is caused by an extra
chromosome 21 and Klinefelter
syndrome is caused by an extra X
chromosome.
www.couriermail.com.au
Inherited Diseases
 a defect in a single gene caused by mutation. Diseases caused
by gene abnormalities include cystic fibrosis, haemophilia,
thalassemia and phenylketonuria (PKU).
www.mun.ca
Inherited Diseases
Cystic fibrosis is an example of
an inherited disease that is
caused by a mutation to the
cystic fibrosis transmembrane
conductance regulator (CFTR)
gene that is found on
chromosome 7. This faulty gene
changes the protein that
regulates the normal movement
of sodium chloride in and out of
cells. This causes the mucussecreting organs to produce
abnormally thick mucus.
www.pathology.org
Inherited Diseases
The CFTR gene is recessive, meaning that a person must have two
copies of the faulty gene for them to develop the disease. The
occurrence of cystic fibrosis varies with ethnic groups.
www.babycenter.com.au
Inherited Diseases
Cystic fibrosis affects the
respiratory, digestive and
reproductive systems, as well as
the sweat glands. The mucus
secreted is very thick and blocks
passageways in the lungs and
digestive tracts. This mucus
causes problems with breathing
and with the digestion and
absorption of nutrients.
www.drugs.com
Inherited Diseases
Some of the symptoms of cystic fibrosis are:
 recurrent and severe chest infections
 malabsorption of nutrients and failure to
thrive
 passing of large, foul-smellingmotions
 Diabetes
 excess salt in sweat
 liver failure
 infertility.
The average life expectancy of someone
suffering from cystic fibrosis is 30–40 years.
journeys4good.com
Inherited Diseases
The treatment of cystic fibrosis
involves relieving the symptoms
as there is at present no cure for
the disease. This treatment
allows sufferers to better cope
with cystic fibrosis in their daily
lives. Treatments include giving
supplements to their diet to
counter the effect of insufficient
digestion and absorption of
nutrients.
blog.23andme.com
Inherited Diseases
Sufferers use daily physiotherapy and
breathing exercises to help prevent
the excessive build-up of mucus in
their lungs. This also helps to prevent
chest infections. Antibiotics and
other medications are given to treat
and control the many infections that
develop. If the lungs are too badly
damaged then lung transplantation
could be an option. Gene therapy is
currently being researched in the
hope that it will eventually be able to
cure cystic fibrosis.
app1.unmc.edu
Nutritional Deficiencies
Nutritional deficiencies can be caused by diets lacking the proper
balance and amount of nutrients. They can also be caused by
psychological conditions that lead to inappropriate diets.
www.guardian.co.uk
Nutritional Deficiencies
A diet that is lacking a vital nutrient,
usually a vitamin or a mineral, can lead
to a nutritional deficiency. Some
examples of these diseases include:
 anaemia, which causes lethargy, and
results from a lack of iron or folic
acid
 beri-beri, which results in retarded
growth, weakened heart muscle,
digestive disorders and muscle
atrophy (wasting), and is caused by a
lack of vitamin B1
agritech.tnau.ac.in
Nutritional Deficiencies
 reduced metabolic rate, low
body temperature, puffiness
around the eyes, protruding
eyes and goitre, all caused by
insufficient iodine
 kwashiorkor, caused by a
deficiency in protein and
resulting in a failure to grow,
swelling of tissue, enlarged
liver, hair changes, apathy and
irritability.
healthinq.blogspot.com
Nutritional Deficiencies
Diseases that have a psychological basis and result in behavioural
disorders that lead to an inappropriate diet include such conditions
as anorexia nervosa, bulimia and obesity.
familymedicinehelp.com
Nutritional Deficiencies
Scurvy is a nutritional deficiency disease that results from a lack of
adequate amounts of vitamin C in the daily diet. It was typically
associated with sailors in the 1700s and has been known to cause
more deaths at sea than storms, shipwreck and combat.
www.chacha.com
Nutritional Deficiencies
Vitamin C (ascorbic acid) is
important in many biological
functions in the body, especially
in the production of substances
required for connective tissue,
bones and dentin. A deficiency
in vitamin C weakens the blood
capillary wall, leading to
bleeding and bruising.
drugline.org
Nutritional Deficiencies
Initial symptoms of scurvy
include:
 pain and tenderness in the legs
 swelling of the long bones
 swollen, purplish and spongy
gums.
www.nejm.org
Nutritional Deficiencies
More advanced symptoms include:
 gangrene (degeneration of tissue)
 reopening of old wounds
 spontaneous haemorrhaging
 purple/black spots on the skin, indicating haemorrhaging
 separation of once-healed broken bones
 bleeding of the membrane covering the front of the eyes or the
eyelids.
If scurvy is left untreated for an extended period of time, death
will result.
Nutritional Deficiencies
Scurvy is rarely seen in developed countries except in people with
poor diets or unusual food habits. It is more commonly found in
developing nations where fresh fruit and vegetables, which act as
rich sources of vitamin C, may not be available. Scurvy can occur
in people of any age, with the risk groups being infants, the elderly
and alcoholics.
www.bubblews.com
Nutritional Deficiencies
The treatment of scurvy is very
easy and simply involves the
inclusion of adequate amounts of
vitamin C in the diet. For more
serious cases, supplements of
vitamin C should be taken daily.
In order to prevent the
occurrence of scurvy, adequate
amounts of vitamin C should be
included in the daily diet.
www.freshforkids.com.au
Environmental diseases
There are many different types of
environmental disease, including:
 lifestyle diseases such as
cardiovascular disease, diseases
caused by substance abuse such as
alcoholism, and smoking-related
diseases
 diseases caused by physical factors
in the environment, such as skin
cancer caused by excessive
exposure to ultraviolet radiation
in sunlight
sienna-x.co.uk
Environmental diseases
 diseases caused by exposure
to chemicals in the
environment, such as lead
poisoning caused by exposure
to high levels of lead in the
atmosphere from pollution or
lead-based paints. Exposure
to asbestos can result in the
fatal disease mesothelioma.
www.apheda.org.au
Environmental diseases
Mesothelioma is a cancer of the mesothelial cells that occur in the
pleura membrane on the outside of the lung. Mesothelioma grows
in the pleural space surrounding the lungs and the tumour may
eventually surround the entire lung.
learningradiology.com
Environmental diseases
The initial stage in the
development of cancer involves a
mutation to a gene that is involved
with the normal process of cell
division. This mutation causes the
process of mitosis to be affected
and can result in the uncontrolled
division of cells, leading to cancer.
At this stage it is not known what
causes the mutation that can lead
to mesothelioma, but it is known
that a high risk factor is exposure
to asbestos fibres.
www.housecalls.net.au
Environmental diseases
When asbestos fibres are inhaled,
most of them stick to the mucus
inside the respiratory passages and
are coughed up or swallowed. The
long, thin fibres of asbestos are not
easily cleared like this and may reach
the ends of the small airways and
penetrate the pleural lining of the
lung and the chest wall. It is these
fibres that in some way damage the
cells and are thought to cause the
mutation that leads to
mesothelioma.
www.mesotheliomaattorneyslawfirm.org
Environmental diseases
The risk of developing mesothelioma is directly linked to the
quantity and length of exposure. Mesothelioma can take 20 to 50
years to develop after exposure to the asbestos. The incidence of
mesothelioma in Australia is 40 cases per million people and is the
highest in the world. Other countries that have mined and used
asbestos have slightly lower rates of occurrence of the disease.
mesotheliomawives.wordpress.com
Environmental diseases
The symptoms of mesothelioma include shortness of breath caused
by the tumour squashing the lungs, chest pain and, in the later
stages of the disease, weight loss, loss of appetite, fatigue, fevers,
night sweats and anaemia.
arca-med.com
Environmental diseases
Mesothelioma is usually incurable by the time it is diagnosed, so
treatment is aimed at controlling the symptoms and extending the
life of the sufferer. It is almost impossible to remove the tumour
surgically. Relief from the symptoms caused by the squashing of
the lungs can be achieved using surgery to insert chest tubes to
drain off the excess fluid.
www.kazanlaw.com
Environmental diseases
Traditional radiotherapy is not successful as it damages normal
lung tissue. Chemotherapy has not proven to be very successful
until recently when new combinations of drugs have been trialled.
Research into new types of treatment is continuing, with the
emphasis on immune system therapies.
www.asbestos.com
Homework
-NIL-work on your assessment task!!