Tuberculosis (TB) is an ancient disease of humans. There is . Ancient Egyptian mummies show signs of spinal TB, and Hippocrates, a Greek physician, . For centuries, TB was called “” because it seemed to consume the body slowly. The disease peaked during the Industrial Revolution due to crowded cities and poor living conditions. In 1882, Dr. Robert Koch , confirming TB’s infectious nature. Breakthroughs like the (1920s) and (1940s–1950s) transformed TB from a death sentence to a treatable disease, though .
Signs, Symptoms, and Causative Agent
Signs & Symptoms
TB symptoms depend on where the infection occurs. Pulmonary TB (lungs) . When TB spreads beyond the lungs (extrapulmonary TB), : , kidney TB may lead to blood in urine, and brain TB can trigger severe headaches. Some people have “,” where the bacteria remain inactive, causing no symptoms. However, latent TB can become active if the immune system weakens.
Causative Agent
TB is caused by , a rod-shaped germ. Unlike other bacteria, M. tuberculosis takes longer to multiply. Its waxy cell wall, made of substances called , protects the bacteria against many antibiotics and the body’s immune defenses. This waxy coat also makes it hard to stain the bacteria in lab tests, requiring special dyes. The bacteria thrive in oxygen-rich environments, such as the lungs. But it can spread to other organs through the bloodstream.
Diagnostic Methods
Healthcare providers utilize several tools to diagnose TB—a or checks whether the immune system has previously encountered the bacteria. For active TB, sputum (mucus from the lungs) is examined under a microscope or cultured to grow the bacteria. Chest X-rays or CT scans help identify lung damage. In resource-limited areas, .
Modes of Transmission
TB when a person with active lung TB coughs, sneezes, or speaks, releasing tiny droplets containing the bacteria. These . Close, prolonged contact (e.g., living with someone with TB) increases infection risk. TB does not spread through touching, sharing food, or kissing. Factors like HIV, diabetes, smoking, or malnutrition weaken the immune system, making it easier for latent TB to become active.
Treatment and Care
Treatment Recommendations
Standard TB treatment involves : isoniazid, rifampin, pyrazinamide, and ethambutol. Newer 4-month regimens using moxifloxacin (a stronger antibiotic) are effective for uncomplicated cases. . Completing the full course is critical to prevent relapse or resistance. Directly observed therapy (DOT), where healthcare workers monitor doses, improves adherence.
Prevention
General Prevention Guidelines
Preventing TB involves early diagnosis, isolation of contagious patients, and good ventilation in homes and hospitals. Covering coughs with a mask or tissue reduces airborne spread. High-risk groups, like HIV patients or TB contacts, should receive .
History and Development of Available Vaccines
The BCG vaccine, , uses a weakened cattle TB strain to train the immune system. While BCG reduces severe TB in children, . Recent trials focus on boosting BCG with new vaccines, .
Current Vaccination Recommendations
BCG is (e.g., India and South Africa) to protect infants. In low-risk regions like the U.S., it’s reserved for healthcare workers exposed to drug-resistant TB. Research continues for universal TB vaccines, but none have surpassed BCG yet.
Conclusion
TB remains a major global health threat, fueled by poverty, crowded living conditions, and drug resistance. While treatments and vaccines have saved millions, eliminating TB requires better diagnostics, shorter drug regimens, and equitable healthcare access. Public awareness and research funding are vital to combat this ancient disease.
Resources and Additional Reading
- World Health Organization (WHO). Global Tuberculosis Report 2024.
- Barberis I, Bragazzi NL, Galluzzo L, Martini M. The history of tuberculosis: from the first historical records to the isolation of Koch's bacillus. J Prev Med Hyg. 2017;58(1):E9-E12.
- How does TB spread? | DC Department of Health. Available at:
- Alsayed SSR, Gunosewoyo H. Tuberculosis: Pathogenesis, Current Treatment Regimens and New Drug Targets. Int J Mol Sci. 2023;24(6):5202. Published 2023 Mar 8. doi:10.3390/ijms24065202
- Nulens, E., Gonzalo Bearman, M. D., & FSHEA, F. (2018). Guide to infection control in the healthcare setting. J ISID, 1-13.
This article was updated in March 2025. .