About: Tuberculosis (TB)

About: Tuberculosis (TB)

  • It is an infectious disease usually caused by Mycobacterium tuberculosis (MTB) bacteria, which generally affects the lungs (Pulmonary TB), but can also affect other parts of the body (Extrapulmonary).
  • It is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze.
  • Most infections show no symptoms, which is also known as latent tuberculosis. People with latent TB do not spread the disease.
    • Active infection occurs more often in people with HIV/AIDS and in those who smoke.
  • Typical symptoms of active TB are a chronic cough with blood-containing mucus, fever, night sweats and weight loss.
  • Diagnosis of active TB is based on chest X-rays, as well as microscopic examination and culture of body fluids (like sputum).
    • Diagnosis of latent TB relies on the tuberculin skin test (TST) or blood tests.
  • Prevention of TB involves screening those at high risk, early detection and treatment of cases and vaccination with the Bacillus Calmette-Guérin(BCG) vaccine.
  • Drug resistant TB: Treatment of TB requires the use of multiple antibiotics over a long period of time.
    • A person has drug resistant TB if the TB bacteria that the person is infected with, will not respond to (or resistant to), at least one of the main TB drugs.
    • There are two main types of drug resistant TB – MDR (multidrug-resistant) TB and XDR (extensively drug-resistant) TB.
      • MDR TB is the name given to TB when the bacteria that are causing it are resistant to at least isoniazid and rifampicin, two of the most effective TB drugs.
      • XDR TB is defined as strains resistant to one of the fluoroquinolones and one of the second line injectable TB drugs amikacin, kanamycin or capreomycin, in addition to rifampicin and isoniazid.

    • END TB Strategy: It is a World Health Organisation (WHO) initiative, adopted by the World Health Assembly in 2014, with the aim to end the TB epidemic globally.
      • It aims at 95% reduction by 2035 in the number of TB deaths compared with 2015, 90% reduction by 2035 in the TB incidence rate compared with 2015 and Zero TB-affected families facing catastrophic costs due to TB by 2035.

TB in India:

  • India accounts for more than 1 in 4 of all cases of active TB diseases (the world’s deadliest infectious killer), including nearly 1.20 lakh cases of drug-resistant forms of TB.
    • A National TB Control Programme (launched in 1962 and revised in 1993) in India registered a 25% fall in the detection of new patients during the first half of 2021 when compared with corresponding period in 2019.

  • India has set a target for complete elimination of Tuberculosis (TB) by 2025, five years ahead of the global (SDGs) target of 2030.
    • According to the WHO, elimination of TB will mean that there should be less than one case of TB for a population of 10 lakh by 2025.
    • For this, the Ministry of Health and Family Welfare, Government of India, recently announced a new National Strategic Plan (NSP) to eliminate TB by 2025.

About the BPaL (Bedaquiline, Pretomanid and Linezolid) Regimen:

  • A three- drug regimen: BPaL is a six-month, all-oral, three-drug regimen that is used to treat people with highly drug-resistant forms of TB.
    • It consists of the TB Alliance developed antibiotic pretomanid, along with two other antibiotics – bedaquiline and linezolid.
    • TB Alliance’s latest trial results show that the high efficacy of the BPaL regimen can be maintained with lower dosing of linezolid, which is associated with challenging side effects, boosting the use of the drug.
    • The BPaL regimen was approved by the drug regulator in India last year.

  • Need:
    • Innovative approaches are urgently needed to turn the tide on TB and are essential to meeting national and global targets for TB elimination.
    • Short, simple, safe and effective therapies must be a cornerstone of any TB control effort.
    • The WHO estimates that Covid-19 related disruptions in access to TB care could cause an additional half a million deaths, losing progress of a decade.

  • Significance:
    • Old treatment regimens require more than 18 months of five or more drugs with low treatment success rates, with many patients stopping treatment due to the length of the treatment.
    • The BPaL regimen can be crucial to reduce treatment time from 18 months to 6 months, with a reported success rate of 90%.

About TB Alliance:

  • TB Alliance, formally the Global Alliance for TB Drug Development, is a not-for-profit product development partnership (PDP) dedicated to the discovery and development of new, faster-acting and affordable tuberculosis (TB) medicines.
    • It was founded in Cape Town, South Africa, and headquartered at New York City, USA.

  • Since its inception in 2000, TB Alliance has worked to grow the field of available treatments for TB and now manages the largest pipeline of new TB drugs in history.

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