Tuberculosis: The World's Most Infectious Killer

Tuberculosis (TB) has plagued humanity for millennia. Evidence of this infectious disease has been found in 9,000-year-old skeletons. Known by different names throughout history, TB remains a significant global health threat, causing more deaths than malaria or HIV/AIDS. But what makes TB so persistent, and what advancements are being made to combat it?

What is Tuberculosis?

Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, which typically spreads through the air, infecting the lungs. Once inhaled, the bacteria are met by immune cells called macrophages, which attempt to engulf and destroy the invaders. However, in individuals with weakened immune systems due to conditions like malnutrition, HIV, diabetes, or pregnancy, the macrophages may not be able to eliminate the bacteria effectively.

How Tuberculosis Works

When the immune system fails to contain Mycobacterium tuberculosis, the bacteria reproduce within the macrophages and form colonies in the lung tissue. As the infection progresses, the bacteria release cell-degrading enzymes that destroy the infected tissue, leading to:

• Chest pain
• Coughing up blood
• Oxygen deprivation

These effects trigger hormonal changes, including decreased appetite and iron production. From the lungs, TB can spread to other parts of the body, including:

• The skeletal system, causing back pain and difficulty moving.
• The kidneys and intestines, causing abdominal pain.
• The brain, causing headaches and impaired consciousness.

The Classic Symptoms

The symptoms of TB often include weight loss, a persistent, bloody cough, and pale skin. In Victorian-era England, TB was known as the "White Plague" due to its ghostly appearance. It was even considered a 'romantic disease' because it disproportionately affected artists and poets living in poverty, who often had weakened immune systems. The disease's symptoms may have even contributed to the myth of vampirism.

Historical Strides Toward a Cure

Despite the misconceptions surrounding TB, significant progress has been made in understanding and treating the disease:

• 1882: German physician Robert Koch identified the bacterial origins of TB.
• 1895: Physicist Wilhelm Roentgen discovered the X-ray, enabling physicians to diagnose and track the disease's progression.
• 1921: Scientists developed the BCG vaccine to combat TB.

These advancements paved the way for the development of antibiotics, which are now the most effective treatments for TB.

The Challenge of Latent Infections

A significant challenge in combating TB is that approximately 90% of infected individuals do not show any symptoms. In these latent infections, the bacteria remain dormant and may only become active when the immune system is weakened. This makes diagnosis difficult and allows the disease to persist undetected.

Treatment of Tuberculosis

Traditional TB treatments can last up to nine months, requiring multiple drugs and carrying a high risk of side effects. This can discourage patients from completing the full course of treatment, leading to the development of drug-resistant bacteria. The disease remains prevalent in 30 countries, many of which face other health crises that exacerbate TB and trigger latent cases. Access to treatment can also be challenging in these regions, and the stigma associated with TB can prevent people from seeking help.

The Future of TB Treatment

Health experts agree that better diagnostics, faster-acting antibiotics, and more effective vaccines are needed to combat TB. Promising advancements include:

• A urine test that provides results in 12 hours.
• A new oral treatment that could reduce treatment time by 75%.

With continued research and development, there is hope that TB can eventually become a disease of the past.