Consumption is the archaic name for a widespread infectious disease now known as Tuberculosis (TB). For centuries, this illness was a source of profound mystery and fear, appearing to slowly and relentlessly drain the life from its sufferers. Clarifying this historical term with the modern medical understanding of TB connects centuries of human experience with a persistent pathogen. TB remains a significant global health challenge, affecting millions of people each year despite being both preventable and curable.
The Origin of the Name
The name “consumption” arose from the most visible symptoms, suggesting the body was being consumed from within. Patients experienced a gradual and profound “wasting,” characterized by severe weight loss, chronic fatigue, and muscle atrophy. This progressive emaciation made it seem as though the body’s substance was being used up by the illness over months or years.
The term derives from the Greek word phthisis, meaning “to waste away,” used by Hippocrates as early as the 5th century BCE. Other symptoms included drenching night sweats, a persistent cough, and coughing up blood. Before the bacterial cause was discovered, this constellation of symptoms was thought to be a sign of slow, inevitable decline.
In the 18th and 19th centuries, consumption reached epidemic proportions, particularly in crowded industrialized cities. It was sometimes called the “Great White Plague” due to the extreme paleness of the afflicted, who were often young adults. The disease was so prevalent that it became a major cultural force, appearing frequently in literature and art.
Modern Understanding: Tuberculosis (TB)
The transition from “consumption” to “tuberculosis” was cemented by the discovery of its specific cause. Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis, a slow-growing microbe. German physician Robert Koch identified this bacillus in 1882, establishing the germ theory basis for the disease.
Transmission occurs through the air when an individual with active pulmonary TB coughs, sneezes, speaks, or sings, releasing tiny droplet nuclei. These microscopic particles remain suspended in the air, allowing others to inhale them. The infection primarily targets the lungs (pulmonary TB), but the bacteria can also cause extrapulmonary TB by affecting sites like the spine, kidneys, brain, and lymph nodes.
The infection exists in two distinct forms: latent TB infection (LTBI) and active TB disease. In latent infection, the immune system contains the dormant bacteria without causing symptoms. Individuals with LTBI are not contagious, but the infection can reactivate into active disease if the immune system weakens, such as due to HIV or diabetes.
Active TB disease occurs when the bacteria multiply and overwhelm the body’s defenses, causing illness and making the person contagious. Only 5 to 10 percent of people with LTBI eventually develop active TB disease. Symptoms of active TB align with the historical description of consumption, including a chronic cough lasting more than three weeks, chest pain, fever, night sweats, and unexplained weight loss.
Diagnosis and Current Treatment
Modern medicine employs several methods to diagnose TB infection and disease, starting with screening tests. The primary tools used to determine infection with Mycobacterium tuberculosis are the Mantoux tuberculin skin test (TST) and the Interferon-Gamma Release Assays (IGRAs), which are blood tests. A positive result indicates infection but does not differentiate between latent and active forms.
If infection is suspected, a chest X-ray is performed to look for characteristic abnormalities in the lungs that suggest active disease. Definitive diagnosis of active TB is achieved through laboratory analysis of sputum, the mucus coughed up from the lungs. Sputum samples are examined using rapid molecular tests and grown in a culture to confirm the bacteria’s presence and test for drug resistance.
Treatment for drug-susceptible active TB is a prolonged course of antibiotics, typically a combination of four drugs taken for at least six months. This multi-drug regimen is necessary to eliminate all bacteria and prevent resistance development. The four primary drugs used are:
- Isoniazid
- Rifampicin
- Pyrazinamide
- Ethambutol
Latent TB is treated with a shorter course of one or two antibiotics to prevent the dormant bacteria from becoming active.
A major challenge is multidrug-resistant TB (MDR-TB), which is resistant to the two most potent first-line drugs: isoniazid and rifampicin. Treating MDR-TB requires longer regimens, often up to 20 months, using second-line drugs that are more toxic. Newer, shorter, all-oral regimens, such as the six-month BPaLM regimen (bedaquiline, pretomanid, linezolid, and moxifloxacin), are now recommended for eligible patients with drug-resistant TB.
Global Impact and Prevention
Tuberculosis remains one of the world’s leading infectious causes of death, with millions falling ill and dying annually. Over 95% of cases occur in low- and middle-income countries, highlighting the link between the disease and socioeconomic factors. High-incidence regions face a substantial burden of illness that strains public health resources.
The Bacillus Calmette-Guérin (BCG) vaccine is the only licensed vaccine available for TB prevention. It is widely used in countries with high TB incidence and routinely administered to infants. The BCG vaccine is particularly effective at preventing severe forms of the disease in young children, such as TB meningitis.
Its efficacy in preventing pulmonary TB in adults is variable, which is why it is not universally used in low-incidence countries. Public health efforts focus on infection control, active case finding, and ensuring treatment compliance. Preventing the spread of drug-resistant strains depends heavily on the successful diagnosis and completion of treatment for all forms of TB.