Tuberculosis

                What is Tuberculosis

Tuberculosis is major causes of death worldwide. According to the estimations done in 2019, ten million people fell ill with this disease. Tuberculosis can be seen in all countries and among all age groups. Tuberculosis is caused mainly by Mycobacterium tuberculosis and occasionally by Mycobacterium bovis and Mycobacterium africanum.

It is an air borne disease. That means it transmitted through the air not by surface contact. Transmission occurs through respiratory droplets. A droplet containing Mycobacterium (tubercle bacilli) travels through the respiratory passage up to the alveoli of the lungs and cause Tuberculosis.

Tuberculosis commonly infected to the lungs, however, can affect other organs in the body except hair and nails.

Risk groups

• ü  Close and prolonged exposure to a Tuberculosis patient
• ü  Diabetes mellitus
• ü  HIV
• ü  Malnutrition
• ü  Chronic alcoholism
• ü  Prolonged steroid therapy
• ü  Malignancy
• ü  Healthcare workers

Classification of Tuberculosis

·         Based on anatomical site

- Pulmonary

This is the Tuberculosis related to the respiratory system (Lungs)

- Extra pulmonary

This occurs outside the lungs (pleura, Lymph nodes, Abdomen, Genito urinary tract, skin, bones, joints, meninges)

·         Based on history of previous Tuberculosis treatment

- New patients

- Previously treated patients 

- Based on HIV status

          HIV positive

          HIV negative

          HIV status unknown TB patients

- Based on drug resistance

•       Mono- resistance: Except Rifampicin, resistant to one first line antibiotic
•       Poly- resistance:     Resistance to more than one anti TB drug other than isoniazid and rifampicin
•      Multi- drug resistance: Resistance to both isoniazid and rifampicin with or without resistance to   other first line drugs (MDR)
•      Extensively- drug resistance: Resistance to both isoniazid and rifampicin, any quinolone and one of second line injectable anti TB drug (XDR)
•      Rifampicin resistance: Resistance to rifampicin with or without resistance to other anti TB drugs except isoniazid (RR)

Common symptoms of Tuberculosis

• ü  Cough
• ü  Shortness of breath
• ü  Chest pain
• ü  Haemopthesis
• ü  Low grade fever
• ü  Night sweat
• ü  Loss of appetite
• ü  Loss of weight (failure to gain weight)
• ü  Tiredness

Screening and Diagnosis

Investigations

1.  Sputum smear microscopy for AFB (Acid fast bacilli)

Mycobacteriun seen under microscope - Ziehl- Neelsen stain 

Need three samples

• ·         First spot specimen
• ·         Early morning specimen
• ·         Second spot specimen

1.     2.   Chest X-ray

1.     3. Culture for AFB (For results it will take about 6-8 weeks)

Positive cultures on Lowenstein- Jensen medium

3. 4. Rapid diagnostic tests

• ü  Gene Xpert MTB/RIF (It is a polymerase chain reaction method for the rapid diagnosis of Mycobacterium tuberculosis (MTB)

• ü  Line probe assay

Molecular diagnostic method

3.       5. Tuberculin skin test (Mantoux)

4.       6. Tissue biopsy and aspirations for the diagnosis of extra pulmonary disease (EPTB)

Treatment of TB

Recommended course of treatment should be followed up to 6-8 months without any interruption. It is a curable disease. Recommendation of drugs should done by a experienced clinician or respiratory physician according to the clinical condition and laboratory diagnosis results. 

a)           a) Drugs

• v  First line antibiotics

Isoniazid

Rifampicin

Pyrazinamide

Ethambutol

• v  Second line antibiotics

Ethionamide

Prothionamide

Cyclosetine

Terizidone

b)          b) TB treatment regimens

-          Intensive phase

-          Continuation phase

c)          c) Fixed dose combination tablets

It depends on the body weight. Formulation for children also have a different criterion.

 

 When using anti TB drugs, there are some side effects. For the monitoring of these conditions Liver function tests are done. Further more according to the clinical conditions other treatment methods are also available for side effects. All these are monitored by experienced health staff.

TB in special situations

• ü  Pregnancy with TB
• ü  Breast feeding with TB
• ü  New born child of a mother with active TB

All above cases can be managed and treated successfully

Management of Co-Morbidities

• ü  TB with HIV infection
• ü  TB infection with Diabetes mellitus
• ü  TB with renal insufficiency
• ü  TB with preexisting liver disease

In above conditions also special treatment regimens are used

Drug resistant Tuberculosis

Drug resistance is a major global threat in tuberculosis control and management

 

Finally, if you have cough more than two weeks and other above-mentioned signs and symptoms it is necessary visit the nearby chest clinic. It will be helpful for you to release from your disease as well as to eradicate this Tuberculosis from the world.