Transcript Lung Disease

Pulmonary
Tuberculosis
Tuberculosis
• Tuberculosis ranks as the third leading cause of
disease and disability among adults in the world, and
nearly one-third of the world's population is infected
with the tuberculosis bacillus.
• Of these cases, more than 9 million people become
sick with TB when their immune system is weakened
and 1.76 million die each year.
Symptoms
•
•
•
•
coughing,
tiredness,
loss of appetite
and weight loss.
• http://www.youtube.com/watch?v=05pbSjkfIyE
• later fever and coughing up blood may occur..
Causes
• Caused by one of two species of rodshaped bacteria;
• Mycobacterium tuberculosis or
Mycobacterium bovis.
• Estimated that up to 30% of the world’s
population has one of these bacteria in
their body.
Tuberculosis bacterium (dyed red) in sputum
Transmission
• Spread through droplets released by coughs,
sneezes, laughing or even talking.
• M. tuberculosis is very resistant and can survive for
several weeks once the droplets have dried.
• TB can be spread from cows to humans as M.bovis
infects cattle and can be passed on in milk.
Who is most “at risk” ?
• Those living or working together for longer periods,
especially in over crowded and poorly ventilated
rooms.
• Those working or living in long term care facilities like
hospitals, prisons and old people’s homes.
• Those from countries where TB is common.
• Those with reduced immune systems.
Course of Infection
First…..
• 1. The bacteria grow and divide within the upper
region of the lungs where there is plenty of oxygen.
• 2. The body’s immune system responds and white
blood cells accumulate at the infection site to ingest
the bacteria.
Then……..
• 3. This leads to inflammation and enlargement of
lymph notes that drain the lungs – primary infection
(usually in children).
• 4. In a healthy person there are few symptoms and
recovery occurs within a few weeks.
• But some bacteria usually remain………
Years later…..
• 5. Many years later these bacteria re-emerge to cause a
second TB infection. This is post-primary tuberculosis and
occurs usually in adults.
• 6. This also occurs in the upper lungs but this time destroys
lung tissue, lung cavities and scar tissue.
• 7. It is difficult to control and the sufferer coughs up blood
and lung tissue. It can then spread to the rest of the body and
becomes fatal.
X–ray showing TB damage
Case Study: China
• In China, tuberculosis is the leading cause of death
from infectious disease among adults.
• Every year, 1.4 million people develop active TB.
• In 1990, 360,000 people in China died
from the disease.
Intervention programme
• In 1991, China revitalized its ineffective tuberculosis program.
• The program adopted the WHO-recommended TB control
strategy, DOTS, through which trained health workers
watched patients take their treatment at local TB county
dispensaries.
• Why do you think this was done?
Impact
• China achieved a 95 percent cure rate for new cases within
two years of adopting DOTS.
• The number of people with TB declined by over 37 percent in
project areas between 1990 and 2000, and 30,000 TB deaths
have been prevented each year.
• More than 1.5 million patients have been treated, leading to
the elimination of 836,000 cases of pulmonary TB.
Cost and cost effectiveness
• The program cost $130 million in total. The World Bank and
the WHO estimated that successful treatment was achieved at
less than $100 per person.
• One healthy life was saved for an estimated $15 to $20.
• The World Bank ranks DOTS as one of the most cost-effective
of all health interventions.