sputum test for tb

tuberculosis is a highly contagious disease spread by bacteria. The bacterium of tuberculosis is called Mycobacterium tuberculosis. it is a rod-shaped bacteria.

The disease infects a healthy person through air or direct contact with the patient. When a sick person coughs or sneezes, millions of TB bacteria float in the air, when a healthy person breathes this infected air, TB bacteria also enter the body of a healthy person. Due to which a healthy person also gets infected.

Examination of TB:

On suspicion of TB disease. He is first identified on the basis of symptoms. The main symptoms of lung TB are.

• Cough with mucus for 2 weeks or more,
• Fever in the evening
• Bodyweight loss,
• Not hungry
• Pain in the chest,
• Blood sputum,
• Trouble breathing along with fever.

Sputum is tested to confirm the pulmonary disease. Sputum examination is divided into 2 parts,

1 - Positive sputum,

2 - Negative sputum.

Tuberculosis bacteria are found in positive sputum tests. While bacteria are not found in negative sputum tests. Sputum is tested at least 2 times. 

Whenever pulmonary TB is suspected, at least 2 samples of sputum are collected and tested under a microscope. first test on the spot, and another test overnight.

Positive Sputum Testing A patient with 1 sample of acid-fast bacilli (A FB) positive, and also seen in the x-ray, is considered as a sputum positive case.


Negative Sputum Testing - A patient with 1 sample of acid-fast bacilli (A FB) negative, and having an x-ray active pulmonary defect is considered a sputum negative case.