19-August-2024-Editorial

SUBCLINICAL TUBERCULOSIS

Subclinical Tuberculosis (TB) poses a significant challenge in managing TB incidence rates, especially in high-burden countries like India.

Despite advancements in TB detection and treatment, subclinical TB remains a hidden contributor to the ongoing transmission of the disease, complicating efforts to control it.

What is Subclinical Tuberculosis?

Subclinical TB refers to a form of TB where individuals do not show the typical symptoms such as a persistent cough.

It is more difficult to detect compared to active TB, which presents with obvious symptoms.

Detection:

• Methods: Subclinical TB is often identified using imaging techniques like chest X-rays or molecular tests.
• Challenges: Routine symptom-based screenings might not detect this form of TB, making it harder to diagnose.

Prevalence:

• Statistics: In the National TB Prevalence Survey (2019-2021), subclinical TB represented 42.6% of cases, with Tamil Nadu reporting a rate of 39%.
• Transmission: Though asymptomatic, individuals with subclinical TB can still spread the bacteria to others.
• Global Context: Countries like Vietnam have effectively reduced TB prevalence by using widespread X-ray and molecular testing, regardless of symptoms.

Impact:

• Transmission: The presence of subclinical TB contributes to the slow reduction in overall TB incidence rates, as it remains largely undiagnosed and untreated.
• Screening Needs: Implementing comprehensive screening strategies, including mobile units and community engagement, could improve detection rates in India.

 About Tuberculosis

• Cause: TB is caused by the bacterium Mycobacterium tuberculosis and primarily affects the lungs.
• Spread: It is transmitted through the air when an infected person coughs, sneezes, or spits.

Symptoms:

• Common Signs: Persistent cough, chest pain, weakness, fatigue, weight loss, fever, and night sweats.
• Risk Factors: Conditions such as diabetes, a weakened immune system, malnutrition, and tobacco use increase susceptibility to TB.

Prevention and Treatment:

• Prevention: Early diagnosis and treatment are crucial. The Bacille Calmette-Guérin (BCG) vaccine helps prevent TB outside the lungs but is less effective for pulmonary TB.
• Prevalence: About 25% of the global population is infected with TB bacteria. 5-10% of these cases progress to active TB.
• Cure: TB can be cured with antibiotics such as isoniazid, rifampin, pyrazinamide, ethambutol, and streptomycin.
• MDR-TB: Multidrug-resistant TB (MDR-TB) is resistant to first-line treatments and requires costly and potentially harmful second-line drugs. Only about 40% of MDR-TB patients received treatment in 2022.

TB and HIV:

• Risk: People with HIV are 16 times more likely to develop TB. TB is the leading cause of death among individuals with HIV.
• Mortality: Without effective treatment, 60% of HIV-negative people with TB and nearly all HIV-positive people with TB are likely to die.

Impact:

• Geographical Burden: TB mainly 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 WHO’s South-East Asian and African Regions.
• Statistics: In 2022, TB caused 1.3 million deaths, including 167,000 deaths among people with HIV. TB is the second leading infectious killer globally, after COVID-19.

Initiatives Related to TB

India:

• National TB Elimination Programme (NTEP): Aims to eliminate TB by 2025.
• Ni-kshay Mitra Initiative: Supports TB patients with direct benefits.
• TB-Mukt Panchayat Initiative: Engages Gram Panchayats to raise awareness, reduce stigma, and improve service uptake.
• Pradhan Mantri TB Mukt Bharat Abhiyan (PMTBMBA): A national campaign to combat TB.

Global:

• Global Tuberculosis Programme: Overseen by WHO, aiming for a TB-free world with zero deaths and disease.
• Global Plan to End TB 2023-2030: Seeks to end TB as a public health challenge by 2030, aligning with UN Sustainable Development Goals (SDGs).
• SDG 3: Focuses on preventing disease and premature death through improved health targets.

Conclusion

Addressing subclinical TB through enhanced screening and detection is crucial for reducing the disease’s overall burden. Continued efforts in both national and global initiatives are vital for controlling TB and achieving the goal of eliminating it as a public health issue.