Do you know India has the largest population of TB patients? Do you know TB can e dormant for years? to know more see the slide.

1. Mycobacterium
tuberculosis
For B.Sc Optometry Students
1882 – Robert Koch – “one seventh
of all human beings die of
tuberculosis and… if one considers
only the productive middle-age
groups, tuberculosis carries away
one-third and often more of
these…”
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2. • In tissue, tubercle bacilli are thin straight rods measuring about 0.4 x
3 micro meter
• On artificial media, coccoid and filamentous forms are seen with
variable morphology from one species to another.
• Mycobacteria cannot be classified as either gram-positive or gram-
negative.

3. • Once stained by basic dyes they cannot be decolorized by alcohol,
regardless of treatment with iodine.
• True tubercle bacilli are characterized by "acid-fastness"—ie, 95% ethyl
alcohol containing 3% hydrochloric acid (acid-alcohol) quickly
decolorizes all bacteria except the mycobacteria.
• Acid-fastness depends on the integrity of the waxy envelope.
• The Ziehl-Neelsen technique of staining is employed for identification of
acid-fast bacteria.
• In smears of sputum or sections of tissue, mycobacteria can be
demonstrated by yellow-orange fluorescence after staining with
fluorochrome stains (eg, auramine, rhodamine).

4. • obligate aerobes
• Increased CO2 tension enhances growth
• growth rate is much slower than that of most bacteria.
• The doubling time of tubercle bacilli is about 18 hours

5. • Mycobacteria are recovered in the sputum of tuberculosis patients and can be
identified using a fluorescent acid-fast stain.
• In the lungs, tuberculosis is identified by the tubercle, a massive granuloma of
white blood cells, bacteria, fibroblasts, and epithelioid cells.
• The center of the tubercle contains caseous (cheesy) pus and bacteria.

9. Symptoms
Although your body may harbor the bacteria that cause tuberculosis, your immune
system usually can prevent you from becoming sick. For this reason, doctors make a
distinction between:
Latent TB. In this condition, you have a TB infection, but the bacteria remain in your
body in an inactive state and cause no symptoms. Latent TB, also called inactive TB or
TB infection, isn't contagious. It can turn into active TB, so treatment is important for
the person with latent TB and to help control the spread of TB. An estimated 2 billion
people have latent TB.
Active TB. This condition makes you sick and can spread to others. It can occur in the
first few weeks after infection with the TB bacteria, or it might occur years later.

10. Symptoms
Signs and symptoms of active TB include:
• Coughing that lasts three or more weeks
• Coughing up blood
• Chest pain, or pain with breathing or coughing
• Unintentional weight loss
• Fatigue
• Fever
• Night sweats
• Chills
• Loss of appetite
Tuberculosis can also affect other parts of your body, including your kidneys, spine or
brain. When TB occurs outside your lungs, signs and symptoms vary according to the
organs involved. For example, tuberculosis of the spine may give you back pain, and
tuberculosis in your kidneys might cause blood in your urine.

11. Tuberculin test
Old tuberculin: a concentrated filtrate of
broth in which tubercle bacilli have grown for 6
weeks
purified protein derivative (PPD): obtained by
chemical fractionation of old tuberculin
A positive tuberculin test
• individual has been infected in
the past. It does not imply that
active disease or immunity to
disease is present.
• at risk of developing disease
from reactivation of the
primary infection,
A negative tuberculin test
• persons who have never been
infected are not subject to that
risk,
In an individual who has not had contact with
mycobacteria, there is no reaction to PPD.
An individual who has had a primary infection
with tubercle bacilli develops induration,
edema, erythema in 24–48 hours, and, with
very intense reactions, even central necrosis.
The skin test should be read in 48 or 72 hours.
Positive tests tend to persist for several days.
Weak reactions may disappear more rapidly

12. Diagnosis
Imaging tests
• a chest X-ray or a CT scan.
• This may show white spots in your lungs where
• it may reveal changes in your lungs caused by active tuberculosis.
• CT scans provide more-detailed images than do X-rays.
Sputum tests
• samples of your sputum
• The samples are tested for TB bacteria.
• Sputum samples can also be used to test for drug-resistant strains of TB
• can take four to eight weeks to be completed.

13. Diaagnosis
Blood tests
• Blood tests may be used to confirm or rule out latent or active tuberculosis.
• measure your immune system's reaction to TB bacteria.
• QuantiFERON-TB Gold in-Tube test and T-Spot. TB test are two examples of TB
blood tests.
• A blood test may be useful if you're at high risk of TB infection but have a negative
response to the skin test, or if you've recently received the BCG vaccine.

14. Treatment
• The two major drugs used to treat tuberculosis are isoniazid and rifampin.
• The other first-line drugs are pyrazinamide, ethambutol, and
streptomycin.
• Second-line drugs include kanamycin, capreomycin, ethionamide,
cycloserine, ofloxacin, and ciprofloxacin.

15. DOTS
Directly observed treatment, short-course
(DOTS/ TB-DOTS) is the name given to the
tuberculosis (TB) control strategy
recommended by the World Health
Organization
DOTS have five main components:
1. Government commitment
2. Case detection by sputum smear microscopy
3. Standardized treatment regimen directly of six to nine months observed by a
healthcare worker or community health worker for at least the first two months
4. A drug supply
5. A standardized recording and reporting system that allows assessment of treatment
results

16. Estimated deaths in
India
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