Tuberculosis: Transmission and Treatment

Tuberculosis: Transmission and Treatment

Tuberculosis (TB) is a potentially chronic infectious illness caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs but can also affect other body parts such as the brain, kidneys, and spine. It is a contagious disease that can spread from person to person.

TB was once rare in developed countries; however, it began increasing in 1985, probably due to the emergence of HIV, the virus that causes AIDS. HIV weakens a person's immune system, making them unable to fight the TB germs. 

Transmission -

TB can spread through direct contact with saliva, sputum, or other body fluids from an infected person. The tuberculosis-causing bacteria spread to individuals through tiny droplets dispensed into the air when an infected person coughs, sneezes or speaks. This droplet may stay in the air for hours or even days in poorly ventilated spaces, transmitting the infection. Extended, close, indoor contact is crucial for tuberculosis to spread from one person to another. 

TB is an airborne manifestation whose transmission depends on the infectiousness of the person with the disease and the infectiousness of the environment. The likelihood of M. tuberculosis transmission depends on several factors, such as

The infectiousness of a person with infectious tuberculosis depends on the number of bacteria expelled and, possibly, the virulence (disease-causing potential) of the bacteria;

The exposure period to an infectious person or air contaminated with tuberculosis bacteria;

The environment surrounding an infectious person, like, the size and the ventilation of the room

The immunity of the exposed person.


There are conditions where the body harbors the TB bacteria, yet the immune system usually prevents the individual from becoming sick. Thus the doctors make a distinction between:

• Latent TB. In this, the person has a TB infection, but the bacteria inside the body are inactive and cause no symptoms. Latent TB/dormant TB/TB infection isn't contagious; however, it may turn into active TB, so treatment is essential.

• Active TB is a condition that makes the person sick and, in most cases, can spread to others. It can transpire weeks or years after infection with the TB bacteria.

Active TB shows the following signs and symptoms-

Coughing for >/= 3weeks

Coughing blood or mucus

Chest pain while breathing or coughing

Unintentional weight loss

Fever and Fatigue

Night sweats and Chills

Appetite loss

Tuberculosis can also affect other body parts, including the kidneys, spine, or brain, the signs and symptoms of which vary according to the organs involved. Like, tuberculosis of the spine might present back pain, and tuberculosis in the kidneys might cause blood in the urine.

People at risk

The Centers for Disease Control and Prevention recommends that people with an increased tuberculosis risk should be screened for latent TB infection. This includes people who:


Use IV drugs

Are the direct contacts of infected people

Are from TB-prevalent nations

Reside or work in areas TB is frequent, like prisons or nursing homes

Are healthcare persons and treat people with a high risk of TB

Are children exposed to adults at risk of TB.

Detection and treatment of latent tuberculosis infection

Diagnosis-The tuberculin skin test is the diagnostic tool for detecting latent infection with M. tuberculosis. However, general population screening is not recommended and is used only in high-risk individuals.

Treatment of Latent Tuberculosis Infection- It helps reduce the probability of the infection, especially a recent one, which will progress to active disease. It usually targets individuals at higher risk of developing active disease, like those with recent infection and AIDS or other conditions that increase the risk of progression.

Side Effects of Treatment- the treatment of latent tuberculosis infection may potentiate liver damage, which is ever higher in those who use alcohol daily, those with pre-existing liver disease, older people, and pregnant or postpartum women.

Diagnosis and treatment of active tuberculosis

Diagnostic Steps - The following are crucial for diagnosing active tuberculosis-

A medical history 

A physical examination

A chest radiograph 

Laboratory tests

Treatment of Active Tuberculosis - Using two drugs in combination has made short-course therapy possible, decreasing the length of treatment from 18 months to 6 to 9 months for drug-sensitive strains. 

Unfortunately, multidrug-resistant tuberculosis strains remain challenging to treat, especially for patients with poorly functioning immune systems. It may demand major surgery (such as complete or partial lung removal), and extended hospital stays. 

Hence the drug therapy regimens vary according to the type of tuberculosis, the probability or identification of multidrug-resistant disease, the presence of other medical conditions like HIV infection or AIDS, patient age, risk of patient non-adherence to the regimen, and treatment side effects. 


Knowing the symptoms of a disease and seeking early medical treatment is crucial to combat any infection. Today, it is almost always possible to cure tuberculosis in people with well-functioning immune systems and drug-sensitive diseases if diagnosed promptly and treated thoroughly.

IJCP Editorial Team

Comprising seasoned professionals and experts from the medical field, the IJCP editorial team is dedicated to delivering timely and accurate content and thriving to provide attention-grabbing information for the readers. What sets them apart are their diverse expertise, spanning academia, research, and clinical practice, and their dedication to upholding the highest standards of quality and integrity. With a wealth of experience and a commitment to excellence, the IJCP editorial team strives to provide valuable perspectives, the latest trends, and in-depth analyses across various medical domains, all in a way that keeps you interested and engaged.

 More FAQs by IJCP Editorial Team


Medtalks is India's fastest growing Healthcare Learning and Patient Education Platform designed and developed to help doctors and other medical professionals to cater educational and training needs and to discover, discuss and learn the latest and best practices across 100+ medical specialties. Also find India Healthcare Latest Health News & Updates on the India Healthcare at Medtalks