Key Questions Answered
Q1. What is Latent Tuberculosis Infection (LTBI)?
Answer: Latent Tuberculosis Infection (LTBI) means that a person has been infected with the TB bacteria, but the bacteria remain inactive (“sleeping”) inside the body. The person does not have active TB disease, feels healthy, and cannot spread TB to others.
Q2. How is Latent TB different from Active TB?
Answer: A person with Active TB develops symptoms such as persistent cough, fever, weight loss and night sweats, and may spread the disease to others through the air.
In Latent TB Infection, the bacteria remain dormant. There are no symptoms, chest X-ray may be normal, and the person is not infectious. However, if immunity becomes weak, latent infection can progress to active TB disease.
Q3. Can a person with Latent TB spread the disease?
Answer: No. A person with Latent TB Infection cannot transmit TB to family members, friends or colleagues. Only people with active pulmonary TB can spread the infection through coughing, sneezing or speaking.
Q4. Who is at higher risk of developing Active TB from Latent TB?
Answer: Some people have a greater chance of latent infection becoming active disease, including:
Household contacts of TB patients
Children below five years of age exposed to TB
People living with HIV
Individuals with diabetes, malnutrition or weakened immunity
Patients receiving long-term immunosuppressive medicines
Persons with chronic kidney disease or certain cancers
These individuals should consult a healthcare provider regarding screening and preventive treatment.
Q5. How is Latent TB diagnosed?
Answer: Latent TB is diagnosed using specific tests such as the Tuberculin Skin Test (TST) / Mx Test or Cy – TB test in appropriate individuals. Before starting preventive treatment, doctors must carefully rule out active TB disease through clinical evaluation and, when indicated, investigations such as chest X-ray or microbiological tests.
Q6. Can Latent TB be treated?
Answer: Yes. TB Preventive Treatment (TPT) can significantly reduce the risk of latent infection progressing to active TB disease.
The choice of preventive treatment depends on national guidelines, the person’s age, medical condition and risk factors. It should always be taken under medical supervision and the prescribed course should be completed.
Q7. Why is Latent TB important for India’s TB Elimination Programme?
Answer: India has made remarkable progress in TB control, but eliminating TB requires preventing future disease as well as treating existing patients.
Identifying people with Latent TB Infection who are at high risk and providing appropriate preventive treatment is an important pillar of the National TB Elimination Programme (NTEP). It helps reduce future TB cases and interrupts the cycle of transmission.
Dr S K Arora’s Take-Home Message :
TB is both preventable and curable. If someone in your family has TB, do not panic—but do not ignore the risk either. Visit nearest health centre for Treatment. Family members, especially young children and other high-risk individuals, should seek medical advice regarding screening for TB infection and eligibility for preventive treatment. All family members should get X ray Chest PA done. Early diagnosis, timely treatment and preventive care can save lives and bring India closer to the goal of a TB-Mukt Bharat.
End Tobacco → End TB → Save Lives
Dr S K Arora
WHO Awardee | Senior Chest Specialist | TB Expert | Tobacco Control Advocate | Public Health India
