Subclinical Tuberculosis

• 19 Aug 2024

Source: TH

Why in News?

Subclinical Tuberculosis (TB) is a growing concern in India, contributing to the slow decline in TB incidence rates despite advances in detection and treatment. 

What is Subclinical Tuberculosis?

• Definition: Subclinical TB refers to a form of TB infection where individuals do not exhibit the typical symptoms of the disease, such as a persistent cough. 
  • This makes it harder to detect compared to active TB, which presents with more apparent symptoms.
• Detection: It is often identified through imaging techniques like chest X-rays or molecular tests, as it may not be noticeable through routine symptom-based screenings.
• Prevalence: Subclinical TB accounted for 42.6% of cases in the National TB Prevalence Survey (2019-2021), with similar findings in Tamil Nadu (39%).
  
  • Although asymptomatic, individuals with subclinical TB can still spread the bacteria to others.
  • High-burden countries, including India, have a considerable proportion of subclinical TB, which remains largely undetected, thus sustaining the transmission of the disease.
  • Countries like Vietnam have successfully reduced TB prevalence by screening entire populations using X-rays and molecular tests, regardless of symptoms.
    • Implementing similar large-scale screening in India would require strategic shifts, including mobile units and community engagement.
• Impact: This form of TB can contribute to the slow decline in overall TB incidence rates, as it remains largely undetected and untreated.

What are the Key Facts About Tuberculosis?

• About: TB is an infectious disease caused by Mycobacterium tuberculosis, that mainly affects the lungs. It spreads through the air when infected people cough, sneeze or spit. 
• Symptoms: Prolonged cough, chest pain, weakness, fatigue, weight loss, fever, and night sweats. 
  • Diabetes, weakened immune system, malnutrition, tobacco use can increase the risk of TB disease. 
• Prevention: Seek medical attention, get tested if at risk, early treatment. The Bacille Calmette-Guérin (BCG) vaccine helps prevent TB outside the lungs but not in the lungs.
• Prevalence and Treatment: About 25% of the global population has been infected with TB bacteria. 5-10% of these infections progress to active TB disease. 
  • TB is preventable and curable with antibiotics, typically including isoniazid, rifampin, pyrazinamide, ethambutol, and streptomycin.
  • Multidrug-resistant TB (MDR-TB) is caused by bacteria resistant to first-line drugs, treatable with costly and toxic second-line drugs. 
    • MDR-TB remains a public health crisis, with only about 2 in 5 people accessing treatment in 2022. 
• TB and HIV: People living with HIV (human immunodeficiency virus) are 16 times more likely to develop TB. TB is the leading cause of death among people with HIV.
  • Without proper treatment, 60% of HIV-negative people with TB and nearly all HIV-positive people with TB will die.
• Impact: TB disproportionately affects adults in low and middle-income countries, with over 80% of cases and deaths occurring in these regions. The highest burden is in the World Health Organization’s (WHO) South-East Asian and African Regions. 
  • A total of 1.3 million people died from TB in 2022 (including 167 000 people with HIV). Worldwide, TB is the second leading infectious killer after Covid-19.
• Initiatives Related to TB:
  • India:
    • The National TB Elimination Programme (NTEP)  to Eliminate TB by 2025.
    • Ni-kshay Mitra Initiative.
    • Direct Benefit Transfer (DBT) provided to TB patients.
    • TB-Mukt Panchayat Initiative: Launched to leverage the support of over 2.5 lakh Gram Panchayats to increase TB awareness, eliminate stigma, and improve service uptake.
    • Pradhan Mantri TB Mukt Bharat Abhiyan (PMTBMBA) 

• Global:

  • The Global Tuberculosis Programme by the World Health Organization works towards the goal of a world free of TB, with zero deaths, disease and suffering due to the disease.

  • Global Plan to End TB 2023-2030 is a plan to end tuberculosis as a public health challenge by 2030, in line with the UN Sustainable Development Goals.

    • SDG 3 aims to prevent needless suffering from preventable diseases and premature death by focusing on key targets that boost the health of a country's overall population.
  • Global Tuberculosis Report.

UPSC Civil Services Examination Previous Year Question (PYQ)

Q. Which of the following diseases can be transmitted from one person to another through tattooing? (2013)

1. Chikungunya
2. Hepatitis B
3. HIV-AIDS

Select the correct answer using the codes given below:

(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Ans: (b)