Tuberculosis | |
---|---|
Other names | Phthisis, phthisis pulmonalis, consumption, great white plague |
Chest X-ray of a person with advanced tuberculosis: Infection in both lungs is marked by white arrow-heads, and the formation of a cavity is marked by black arrows. | |
Specialty | Infectious disease, pulmonology |
Symptoms | Chronic cough, fever, cough with bloody mucus, weight loss[1] |
Causes | Mycobacterium tuberculosis[1] |
Risk factors | Smoking, HIV/AIDS[1] |
Diagnostic method | CXR, culture, tuberculin skin test, QuantiFERON[1] |
Differential diagnosis | Pneumonia, histoplasmosis, sarcoidosis, coccidioidomycosis[2] |
Prevention | Screening those at high risk, treatment of those infected, vaccination with bacillus Calmette-Guérin (BCG)[3][4][5] |
Treatment | Antibiotics[1] |
Frequency | 25% of people (latent TB)[6] 10.6 million (active TB)[1] |
Deaths | 1.3 million (2022)[6] |
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption,[7] is a contagious disease usually caused by Mycobacterium tuberculosis (MTB) bacteria.[1] Tuberculosis generally affects the lungs, but it can also affect other parts of the body.[1] Most infections show no symptoms, in which case it is known as latent tuberculosis.[1] Around 10% of latent infections progress to active disease that, if left untreated, kill about half of those affected.[1] Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss.[1] Infection of other organs can cause a wide range of symptoms.[8]
Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze.[1][9] People with latent TB do not spread the disease.[1] Active infection occurs more often in people with HIV/AIDS and in those who smoke.[1] Diagnosis of active TB is based on chest X-rays, as well as microscopic examination and culture of bodily fluids.[10] Diagnosis of latent TB relies on the tuberculin skin test (TST) or blood tests.[10]
Prevention of TB involves screening those at high risk, early detection and treatment of cases, and vaccination with the bacillus Calmette-Guérin (BCG) vaccine.[3][4][5] Those at high risk include household, workplace, and social contacts of people with active TB.[4] Treatment requires the use of multiple antibiotics over a long period of time.[1] Antibiotic resistance is a growing problem, with increasing rates of multiple drug-resistant tuberculosis (MDR-TB).[1]
In 2018, one quarter of the world's population was thought to have a latent infection of TB.[6] New infections occur in about 1% of the population each year.[11] In 2022, an estimated 10.6 million people developed active TB, resulting in 1.3 million deaths, making it the second leading cause of death from an infectious disease after COVID-19.[1] As of 2018, most TB cases occurred in the WHO regions of South-East Asia (44%), Africa (24%), and the Western Pacific (18%), with more than 50% of cases being diagnosed in seven countries: India (27%), China (9%), Indonesia (8%), the Philippines (6%), Pakistan (6%), Nigeria (4%), and Bangladesh (4%).[12] By 2021, the number of new cases each year was decreasing by around 2% annually.[1] About 80% of people in many Asian and African countries test positive, while 5–10% of people in the United States test positive via the tuberculin test.[13] Tuberculosis has been present in humans since ancient times.[14]