What is Tuberculosis?

Tuberculosis (TB) is a contagious disease caused by the bacterium Mycobacterium tuberculosis. TB mainly affects the lungs but can also target other parts of the body, such as the kidneys, spine, and brain. It spreads through the air when a person with active TB coughs, sneezes, or talks.

Diagram of TB infection in lungs

How Does TB Infect the Body?

  • Entry: TB bacteria enter the body through inhaled droplets.
  • Primary Infection: Bacteria settle in the lungs, causing local inflammation.
  • Immune Response: The body tries to contain the bacteria by forming granulomas (small clusters of immune cells).
  • Latent vs. Active TB:
    • Latent TB: The bacteria remain inactive; the person has no symptoms and isn’t contagious.
    • Active TB: The bacteria multiply, causing symptoms and spreading to others.

Symptoms of TB

  • Persistent cough (lasting more than 3 weeks)
  • Chest pain
  • Coughing up blood
  • Fatigue and weakness
  • Weight loss
  • Fever and night sweats

Diagnosis and Treatment

Diagnosis

  • Skin Test (Mantoux Test): A small amount of TB protein is injected under the skin; swelling indicates exposure.
  • Blood Tests: Detect immune response to TB bacteria.
  • Chest X-ray: Shows lung damage.
  • Sputum Test: Checks for bacteria in mucus from the lungs.

Treatment

  • Antibiotics: TB is treated with a combination of antibiotics over 6–9 months. Common drugs include isoniazid, rifampin, ethambutol, and pyrazinamide.
  • Drug-Resistant TB: Some TB strains resist standard antibiotics, requiring stronger medications.

TB and CRISPR Technology

CRISPR is a powerful gene-editing tool that allows scientists to change DNA sequences with high precision. Researchers use CRISPR to:

  • Study how TB bacteria evade the immune system.
  • Identify genes in Mycobacterium tuberculosis that make it resistant to antibiotics.
  • Develop new treatments by disabling harmful TB genes.

CRISPR gene editing illustration

Famous Scientist: Robert Koch

  • Robert Koch discovered the TB bacterium in 1882.
  • He developed methods to grow bacteria in the lab, helping scientists understand infectious diseases.
  • Koch won the Nobel Prize in Physiology or Medicine in 1905 for his work on TB.

Interdisciplinary Connections

  • Biology: TB involves the immune system, bacteria, and human health.
  • Chemistry: Antibiotics are chemical compounds that target TB bacteria.
  • Technology: CRISPR and advanced diagnostics use engineering and computer science.
  • Public Health: TB control requires education, policy, and global cooperation.
  • History: TB has shaped societies and inspired medical advances.

Three Surprising Facts

  1. TB is still one of the top infectious killers worldwide. In 2022, over 10 million people fell ill with TB, and 1.6 million died (World Health Organization).
  2. TB bacteria can survive inside the body for years without causing symptoms. This latent phase makes TB hard to eliminate.
  3. CRISPR is being used to create rapid TB tests and new treatments. Scientists can now target the genes that make TB bacteria resistant to drugs.

Most Surprising Aspect

The most surprising aspect of TB is its ability to hide inside the body for years without causing symptoms. This “latent TB” can reactivate decades later, especially if the immune system weakens. This makes TB especially challenging to control and eradicate.

Recent Research

A 2022 study published in Nature Communications showed that CRISPR-based diagnostics can detect TB bacteria in patient samples much faster than traditional methods. This technology could help stop TB outbreaks by identifying cases early and accurately (Nature Communications, 2022).

Prevention

  • Vaccination: The BCG vaccine protects against severe TB in children.
  • Good Ventilation: Reduces the risk of airborne transmission.
  • Early Detection: Testing and treating infected individuals prevents spread.
  • Healthy Living: Strong immune systems help fight TB.

Summary Table

Aspect Details
Cause Mycobacterium tuberculosis
Transmission Airborne droplets
Symptoms Cough, chest pain, fever, weight loss
Diagnosis Skin, blood, X-ray, sputum tests
Treatment Multiple antibiotics
Prevention Vaccine, ventilation, early detection
Technology CRISPR for gene editing and diagnostics
Famous Scientist Robert Koch

References

  • World Health Organization. (2023). Tuberculosis Fact Sheet. WHO TB Facts
  • Nature Communications (2022). “CRISPR-based diagnostics for rapid detection of Mycobacterium tuberculosis.” Read Article

TB bacteria under microscope