A specific disease caused by the presence of Mycobacterium tuberculosis , which may affect almost any tissue or organ of the body, the most common seat of the disease being the lungs; the anatomical lesion is the tubercle, which can undergo caseation necrosis; local symptoms vary according to the part affected; general symptoms are those of sepsis: hectic fever, sweats, and emaciation; often progressive with high mortality if not treated.
Approximately 2 billion people — one-third of the human population — are currently infected with TB, with one new infection occurring every second.
TB has plagued human beings for millennia.
Signs of tubercular damage have been found in Egyptian mummies and in bones dating back at least 5,000 years.
Today, despite advances in treatment, TB is a global pandemic, fueled by the spread of HIV/AIDS, poverty, a lack of health services and the emergence of drug-resistant strains of Mycobacterium tuberculosis, the bacterium that causes the disease.
Patients are much more likely to contract TB from a family member or close co-worker than from a stranger on a bus or in a restaurant, although there have been a number of cases of transmission on plane flights.
A person with active TB who's been effectively treated for at least two weeks is no longer contagious and can't spread the bacteria to others.
Although TB can affect other organs and tissues, it primarily attacks the lungs.
Approximately two to eight weeks after lungs are infected with M. tuberculosis, immune system springs into action.
People infected with M. tuberculosis within the past two years Older adults People with other medical conditions that appear to increase the risk of TB, such as diabetes and silicosis People born in areas of the world where TB is common, such as Asia, Africa or Latin America People with HIV infection or an otherwise compromised immune system Close contacts of people with infectious TB People at higher risk of active TB disease People at higher risk of TB infection
Other people who may be exposed to TB on the job, such some health care professionals People who live or work in residential facilities, such as nursing homes or correctional facilities People who inject illicit drugs or abuse alcohol People who inject illicit drugs People with chest X-ray findings that show previous TB disease People with poor access to health care, including homeless people People at higher risk of active TB disease People at higher risk of TB infection
Until the mid-20th century, people with TB were routinely cared for in sanitariums — often for years — where the clear, cold air, abundant food and enforced rest were believed to heal the lungs and halt the wasting that's characteristic of the disease.
Often, the treatment not only helped cure TB, but prevented its spread.
Today, medications are the cornerstone of TB treatment, but the therapy is still lengthy.
In general, TB is a preventable disease. From a public health standpoint, the best way to control TB is to diagnose and treat people with TB infection before they develop active disease and to take careful precautions with hospitalized TB patients.