HeroRATS: Revolutionary Solution for TB Diagnosis?

Syllabus:

GS 3: Health

Why in the News?

Recently, innovative TB detection using HeroRATS gained attention as experts suggested its potential for India. With TB elimination targeted by 2025, integrating such methods could enhance early diagnosis and reduce transmission.

HeroRATS: Revolutionary Solution for TB Diagnosis?

Using Animals to Detect Tuberculosis

  • Tuberculosis (TB) remains one of the deadliest diseases worldwide, with over 10 million new infections annually.
  • India accounts for 28% of global cases, leading to nearly 5 lakh deaths per year—roughly one TB death every minute.
  • Despite significant medical advancements, early detection remains a major challenge, especially in rural areas.
  • The National TB Elimination Programme (NTEP) aims to eliminate TB in India by 2025, five years ahead of the global goal.
  • However, even though the India TB Report 2024 highlights a 16% reduction in TB cases and an 18% drop in TB-related deaths since 2015, elimination still seems difficult.
  • Early detection is critical, but traditional TB diagnostic tools have limitations.
  • Many people, especially children and those with low bacterial loads, receive false-negative results, delaying treatment.
  • Moreover, testing centres are often far from remote communities, making diagnosis difficult.
  • Even though TB treatment is free, travel costs discourage timely testing.
  • Innovative approaches, such as using trained animals to detect TB, could be a game-changer in addressing these challenges.

Challenges in TB Diagnosis

Inefficiency of Traditional Methods

  • Sputum-smear microscopy, a common diagnostic tool, often fails to detect early-stage TB.
  • People with low bacillary loads, such as children and HIV-positive individuals, are particularly affected.
  • Many patients do not seek a second diagnosis after receiving a negative test, leading to late detection and higher transmission.

Lack of Access to Testing Facilities

  • Many rural and underserved areas have limited diagnostic facilities.
  • People travel long distances to reach testing centers, delaying diagnosis.
  • Although TB treatment is free, the cost of travel and lost wages discourages people from getting tested.

Need for Alternative Approaches

  • Faster, cost-effective, and highly sensitive methods are required to detect TB early.
  • Using animals, particularly trained rats, has shown promising results in detecting TB cases that standard methods miss.

How African Giant Pouched Rats Detect TB

  • APOPO, a Tanzania-based non-profit, trains African giant pouched rats—nicknamed HeroRATS—to detect TB in sputum samples.
  • These rats have an exceptional sense of smell, enabling them to identify TB cases with high accuracy.
  • They serve as a secondary diagnostic tool, improving early detection in resource-limited areas.

Training Process of the Rats

  • Training starts at 2-3 months and lasts up to nine months.
  • The rats are exposed to TB-positive sputum samples and rewarded with a smoothie for correct identification.
  • Positive reinforcement helps sharpen their skills.

Speed and Accuracy of Detection

  • A single rat can analyze 100 samples in just 20 minutes, compared to three to four days using conventional methods.
  • Samples are placed in a chamber with sniffing holes, where the rats indicate a positive case by holding their nose over a sample for three seconds.
  • Further testing is conducted using Ziehl-Neelsen (ZN) and fluorescent microscopy.

Success in Other Countries

  • A 2023 study in Tanzania analyzed 35,766 patients:
  • 1,900 were smear-positive (detected using standard methods).
  • 33,866 tested negative, but the rats identified 2,029 additional TB cases.
  • The rats performed six times better when detecting low-bacterial-load cases.
  • The method has already been successfully implemented in Tanzania, Mozambique, and Ethiopia.

Disease Detection Using Animals

How Animals Detect Diseases

  • Many animals have exceptional olfactory abilities and can detect diseases by identifying chemical biomarkers.
  • Research shows that animals can outperform traditional diagnostic tools in certain cases.

Dogs for Disease Detection

  • Dogs have between 125 to 300 million olfactory receptors in their noses.
  • They use Jacobson’s organ to detect chemical signals related to diseases.
  • Studies indicate that dogs can even identify Parkinson’s disease in humans.

Ants and Cancer Detection

  • A French study in Science Direct found that ants can detect cancer cells in three days using chemical cues and sugar rewards.
  • Ants require minimal training and can be a cost-effective diagnostic tool.

Honeybees and Lung Cancer Detection

  • Research by Debajit Saha at Michigan State University found that honeybees can detect lung cancer biomarkers in breath samples.
  • Honeybees could distinguish between small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) with 88% accuracy.
  • This method could help in early-stage cancer detection.

Could HeroRATS Be Used in India?

  • Given India’s high TB burden, integrating HeroRATS into NTEP could significantly improve early detection.
  • The approach could be particularly beneficial for children and smear-negative patients.

Expert Opinions from India

  • Dewraj Sarkar, District TB Officer (Darjeeling), believes the NTEP must evaluate the feasibility of this approach.
  • Rajendra Kumar, State TB Officer (Chandigarh), supports using rats as a secondary screening tool due to their cost-effectiveness and speed.
  • Sandeep Sangale, STO (Maharashtra), suggests that a collaboration with APOPO could help high-burden states like Maharashtra detect cases faster.

Feasibility and Challenges

  • A partnership between India’s Central TB Division and APOPO would be essential for implementation.
  • The COVID-19 pandemic delayed discussions, but experts believe reviving talks could be crucial.
  • A phased rollout, starting with high-TB burden states, could assess the feasibility of HeroRATS in India.
  • TB continues to be a major health crisis in India, with millions of undiagnosed cases due to inefficient diagnostic methods and limited access to testing.

Conclusion

Tuberculosis remains a major health challenge in India due to undiagnosed cases and limited testing access. Implementing HeroRATS, proven effective in Tanzania and Ethiopia, could enhance early detection, reduce transmission, and support India’s TB elimination goal.

Source:

The Hindu

Mains Practice Question:

Discuss the challenges in tuberculosis (TB) detection in India and evaluate the potential of innovative diagnostic methods like HeroRATS in strengthening the National TB Elimination Programme.