Tuberculosis |
Treatment and Evaluation
Tuberculosis is diagnosed by a positive tuberculin
skin test, sputum culture, chest X-rays, bronchoscopy and polymerase
chain reaction test.
A positive tuberculin skin test indicates that an
individual has been infected and has produced antibodies
against the bacillus. By itself, the positive skin
test does not indicate the presence of active disease.
It is important that the material used for skin testing
be standardised to minimise the number of false-
positive and false-negative results.
When active TB disease is present, the tubercule bacillus
can be cultured from the sputum and may be seen with
an acid-fast stain.
Chest X-rays of individuals
with current or previous active disease demonstrate
characteristic changes. Nodules, calcifications,
cavities and hilar enlargement (enlarged mediastinal
lymph nodes) commonly are seen in the upper lobes.
A positive skin test indicates the need for yearly chest
X-rays to detect active disease.
Bronchoscopy can be used in people who are unable to cough up sputum.
Polymerase chain reaction, allows detection of M. tuberculosis DNA,
this is generally performed on sputum samples. Results can be
available within 6 hours.
TB Control Programs depend on laboratory services of the
reliable and timely confirmation of the presence of M.tuberculosis.
Tuberculosis is graded as follows to aid in evaluation
and determination of appropriate therapy:
Treatment consists of antibiotic therapy to control
active or dormant tuberculosis and prevent transmission
.The choice of drugs and the duration of treatment
depend on the individual's health history,
the likelihood of bacterial resistance to certain drugs,
and the presence of active disease. The waxy coat of
M.tuberculosis inhibits many
common drugs. Previously tuberculosis was treated with two
effective drugs. Isoniazid
with either rifampicin or ethambutol usually was used
for 6 to 9 months. Today, with the increased numbers
of immunosuppressed and susceptible individuals and
drug-resistant bacilli, the recommended treatment
for those at high risk is a combination of four drugs:
isoniazid, rifampicin, pyrazinamide, and ethambutol or streptomycin. The major determinant of treatment outcome
is patient adherence to the medication regimen. Non-compliant patients are at great risk of developing
multi-drug resistant tuberculosis. TB Bacilli that become resistant to both isoniazid and rifampicin are extremely
difficult to treat.
Diagnosis
Treatment
