Drug-Resistant TB 

Drug-Resistant TB 

This article covers “Daily Current Affairs” and the topic details “Drug-Resistant TB”. The topic “Drug-Resistant TB” has relevance in the “Science and Technology” section of the UPSC CSE exam.

For Prelims:

What is Tuberculosis (TB)?
What is DR TB? 

For Mains:

GS3:  Awareness in Health 

Why in the news?

The formidable problem of drug-resistant tuberculosis (DR-TB) necessitates immediate and serious consideration. Given that India bears a quarter of the global burden of DR-TB cases, the way India responds could influence how other nations confront this escalating danger.

Tuberculosis (TB)

  • Tuberculosis (TB) is an infectious disease caused by bacteria that are transmitted through the air from one person to another.
  • While TB primarily affects the lungs, it can also target other body parts such as the brain, kidneys, or spine. 
  • While TB is generally treatable and can be cured, individuals with TB can face fatal outcomes if they are not provided with appropriate treatment.

 

Emergence of Drug-Resistant TB

  • Occasionally, a more challenging form known as drug-resistant TB arises when the TB bacteria become immune to the drugs typically employed for TB treatment. 
  • This implies that the drugs are no longer effective in eradicating the TB bacteria.

 

Transmission of Drug-Resistant TB

  • The transmission of drug-resistant TB occurs through the same methods as drug-susceptible TB. 
  • This airborne bacteria can be inhaled by people in close proximity, leading to infection.

 

Drug-Resistant Tuberculosis: Causes and Risk Factors

  • Incomplete Treatment Courses: Individuals failing to complete the full prescribed course of TB treatment contribute to the development of drug-resistant strains.
  • Inaccurate Prescription: Health care providers prescribing treatments with incorrect dosages or durations inadvertently foster the emergence of drug resistance.
  • Unavailability of Proper Medications: A lack of access to appropriate TB drugs can hinder effective treatment, thereby enhancing the risk of drug-resistant TB.
  • Quality of Drugs: Poor-quality drugs, characterized by substandard potency or formulation, can render TB treatment ineffective and potentially lead to drug resistance.

 

Types of DR- TB 

  • Multidrug-Resistant TB (MDR TB)
    • Multidrug-resistant TB (MDR TB) arises from TB bacteria exhibiting resistance to two pivotal TB drugs: isoniazid and rifampin
    • These two drugs form the backbone of treatment for all individuals afflicted by TB disease. 
    • The consultation of TB experts is imperative when managing MDR TB cases
  • Pre-Extensively Drug-Resistant TB (pre-XDR TB)
    • Pre-Extensively Drug-Resistant TB (pre-XDR TB) constitutes a subset of MDR TB. 
    • It develops when TB bacteria display resistance to isoniazid, rifampin, and either a fluoroquinolone or a second-line injectable drug (such as amikacin, capreomycin, and kanamycin)
  • Extensively Drug-Resistant TB (XDR TB)
    • Extensively drug-resistant TB (XDR TB) represents a rare form of MDR TB with heightened resistance. 
    • TB bacteria in XDR TB cases are not only impervious to isoniazid and rifampin but also to a fluoroquinolone and a second-line injectable drug (like amikacin, capreomycin, and kanamycin). 
    • Alternatively, XDR TB can emerge when TB bacteria resist isoniazid, rifampin, a fluoroquinolone, and either bedaquiline or linezolid.
    • Because XDR TB displays resistance against the most potent TB medications, patients confront treatment options of significantly diminished efficacy. 
    • Notably, individuals with compromised immune systems, particularly those with HIV infection or other immune-weakening conditions, face heightened vulnerability.
    • Such individuals are not only more prone to developing TB disease post-infection but also encounter an elevated risk of mortality once the disease takes hold.

 

TB Situation in India

  • The situation of multidrug/rifampicin resistant TB (MDR/RR-TB) in India is concerning. The WHO estimates around 119,000 new MDR/RR-TB cases emerge in India annually. However, in 2022, the Indian TB program reported only around 64,000 cases. 
  • India aims to eliminate TB by 2025, with targets like reducing new TB cases to 44 per lakh population, mortality to 3 deaths per lakh, and eliminating catastrophic costs.

 

Challenges in Achieving India’s TB Elimination Targets

  • MDR-TB as a Major Hurdle: 
    • Rifampicin resistance is a significant concern, as it is the most effective first-line drug. 
    • Resistance to rifampicin and isoniazid is termed MDR-TB. Despite progress, DR-TB remains a public health threat in India.
  • Divergence from WHO Recommendations: 
    • While WHO recommended the use of the BPaL regimen (Bedaquiline, Pretomanid, and Linezolid) for DR-TB patients, India has continued using a mix of treatment options, many of which are challenging to adhere to. 
    • The BPaL regimen has shown an 89% success rate, reduced pill burden, and shorter treatment duration.
  • Reliance on Outdated Detection Methods: 
    • India continues to rely on traditional methods like sputum smear microscopy, which only detects half of all TB cases and cannot identify drug resistance. 
    • Molecular diagnostics, recommended by WHO, are more accurate and cost-effective.
  • Private Sector Engagement: Scaling up private sector involvement is crucial, given their potential to improve treatment outcomes.
  • High DR-TB Burden: DR-TB cases require expensive specialized drugs and prolonged treatment.
  • Research and Cost Control: Lack of research and cost control measures hinder effective TB management.
  • Undernutrition and Immunity: Undernourishment weakens immunity, leading to TB reactivation.
  • Treatment Discontinuation: Limited resources and financial constraints cause many to abandon treatment midway.
  • Drivers of TB Epidemic: Delayed diagnosis, inadequate treatment, high recurrence rates, drug resistance, comorbidities (diabetes, HIV), and urbanisation contribute to the ongoing TB crisis.

 

Achievements and Path Forward

  • Enhanced Diagnosis: Rapid molecular diagnostics, akin to those used during the COVID-19 pandemic, aid in rapid TB detection.
  • Reduced DR-TB Treatment Duration: Shortened treatment duration (from 24 to 6 months) with oral medications, avoiding painful injections.
  • Recommended BPaL Regimen: Shifting to the WHO-recommended BPaL regimen promises higher success rates and substantial cost savings.
  • Availability of New Tools: Accurate diagnostic tools can facilitate the cure of DR-TB within six months using oral medications.

 

Advancing TB Management in India

  • Access to optimal diagnostic and treatment options is a fundamental right. Leveraging advanced tools is essential to prevent suffering and deaths due to drug-resistant TB. 
  • India’s adoption of the WHO-recommended BPaL regimen, wider implementation of accurate diagnostics, and continued efforts are pivotal to achieving the ambitious goal of TB elimination by 2025.

 

Sources:  

India’s TB problem and the right to treatment | The Indian Express

Yojna daily current affairs eng med 16th August 2023

 

Q1. With reference to Tuberculosis, consider the following statements: 

  1. Tuberculosis (TB) is caused by a virus that spreads through the air from person to person.
  2. TB can affect various body parts beyond the lungs, such as the brain, kidneys, or spine.
  3. Drug-resistant TB can occur when the TB bacteria develop immunity to commonly used drugs.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 3 only 

(d) None 

Answer: (b) 

 

Q2. Consider the following : 

  1. Poor-quality drugs, characterised by substandard potency or formulation, can render TB treatment ineffective and potentially lead to drug resistance. 
  2. Multidrug-resistant TB (MDR TB) develops when TB bacteria become resistant to the second line of drugs.
  3. Isoniazid and rifampin are among the primary drugs used for initial treatment.

How many of the above mentioned statements are correct ?

(a) Only one 

(b) Only two 

(c) All three 

(d) None 

Answer: (b)

Q3. What does the term “drug-resistant tuberculosis (DR-TB)” refer to, and why is it considered a pressing concern? How can India’s response to the issue of drug-resistant tuberculosis influence the global approach to this problem?

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