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Lung Disease
Pulmonary Tuberculosis (TB)
Background
• Usually found in the
lungs as transmitted via
droplets in the air.
• Infectious disease that
is the biggest killer –
approx 2 million people
per year die from it.
• Previously known as
consumption.
• Pre-WW2 campaign.
Causes
• Rod shaped bacteria
• Myobacterium
tuberculosis
• Myobacterium bovis
• 30% world’s population
have one form in their
blood stream.
Symptoms
• Persistent cough
• Tiredness
• Loss of appetite leading
to weight loss
• Fever
• Coughing up of blood
droplets
Transmission
• Through the air by
droplets by sneezing,
coughing, laughing esp in
crowded places or
friends/relatives
• Resistant bacterium, can
survive many weeks
• M bovis infects cattle and
can contaminate milk
Risk Groups
• Living and sleeping in
overcrowded conditions
• Work or live in long-term
care facilities
• People from countries
where TB is prevalent
• Reduced immunity
(children/HIV
patients/elderly/alcoholic
s/homeless/transplant
patients/malnourished)
Course of infection
Early infection
Primary Infection
(occurs in children)
Post-Primary infection
(many years later –
adults)
Can be FATAL
Bacteria grow and divide Inflammation and
in upper regions of the
enlargement of lymph
lungs
nodes
Bacteria re-emerge to
cause a 2nd TB infection
Phagocytes accumulate
at these sites to ingest
bacteria
Bacteria destroy lung
tissue resulting in
cavities and scar tissue.
Healthy person will
control infection in a
few weeks but a few
bacteria remain
Coughs up lung tissue,
blood and bacteria, can
spread to rest of the
body.
Prevention and Control of TB
• Vaccination of those
without immunity –
weak strain of M bovis
• Better education
• Better housing
• Improved health
facilities
• Better nutrition
• Drug treatment (6-9
months)
• Why has there been an
increase of TB recently in
developed countries?