It
is highly communicable bacterial disease often found among people living in
dark and dirty congested places. The germs of TB may invade any part of body
and multiply and destroy the tissues. However lungs are the favourite site of
infection. On the basis of the site of infection TB may be, Pulmonary TB or
extra pulmonary TB. In pulmonary TB site of infection is lungs while in extra
pulmonary TB the site of infection is other parts of body except lungs.
Occurrence: It is found in any part of world. In
Nepal, it is more common in rural areas. About 50000 new cases are reported
every year and about 15000 to 16500 people die each year due to TB.
Causative organism: The causative organism of TB is
bacterium, Mycobacterium tuberculosis
which is a small rod shaped bacteria.
Reservoir and source of infection: This bacterium is restricted to
infected person. However in some cases infected cattle also serve as reservoir.
The source of infection in pulmonary TB is respiratory secretions (oral and
nasal) and the milk of infected cattle. The extra pulmonary TB is usually not
responsible for infection.
Mode of transmission:
TB spreads mostly by throat and nose discharges of infected person. The
infection is by direct or indirect contact. When a TB patient sneezes or coughs,
the bacteria spreads in air and when a healthier person breaths that air the
bacteria enters inside and the person is infected. Thus the infection is air
borne or droplet infection.
Incubation period: The incubation period varies from few
weeks to years.
Symptoms: The bacteria produce a toxic
substance tuberculin which results into different disorders. The main symptoms
of pulmonary TB are
·
Fever
·
Cough
·
Sputum
containing blood
·
Loss
of body weight
·
Chest
pain
·
Loss
of appetite
·
Weakness
The
extra pulmonary TB remains characterized by acute pain at the affected area.
Diagnosis: TB is diagnosed by chest x-ray,
Sputum test or tuberculin/ Montoux test.
Preventive methods
(Prophylaxis): The
preventive methods are:
·
Mass
education about TB.
·
Improvement
in housing, personal hygiene, nutrition and living standards.
·
Infected
person must cover mouth and nose during sneezing and coughing.
·
Milk
of infected cattle must not be used for drinking.
·
Immunization
by BCG( Bacillus Calmette Guerin)
Treatment: The International union against
tuberculosis and lung diseases (IUATLD) has introduced DOTS programme (Directly
observed treatment- short course) for the treatment of TB. The DOTS mainly
includes good quality diagnosis and short course chemotherapy given under
systematic monitoring and direct supervision.
For
the treatment streptomycin, Para amino salicylic acid (PAS), Isoniazid,
Ethambutol etc. are used.