Tuberculosis (TB) is a well-known disease since ancient times. The symptoms of TB include a low-grade fever, night sweats, a loss of appetite, fatigue, coughing up sputum, bronchial or pulmonary hemorrhage, persistent chest pain, breathlessness, etc. So what causes this terrible disease?
TB is caused by the infection with mycobacterium tuberculosis, a bacterium that can enter the body through respiratory, digestive tract or wounds in the skin. Most of the bacteria enters the body through respiratory. When a TB patient coughs, sneezes, or spits, tiny droplets containing the bacteria are released into the air. Healthy people who inhale the bacteria will develop lung infection and catch pulmonary TB.
Pulmonary TB may manifest itself in several forms, including primary pulmonary TB and secondary pulmonary TB. Primary pulmonary TB refers to the initial infection with mycobacterium tuberculosis; secondary pulmonary TB is defined as a second outbreak of mycobacterium tuberculosis in the case of weakened immune system after the primary infection has been largely treated. Meanwhile, mycobacterium tuberculosis may also cause extrapulmonary infection, because it can spread from the initial location to other parts of the body through the bloodstream, such as the brain, kidneys and digestive tract, causing brain tuberculosis, kidney tuberculosis and intestinal tuberculosis.
In addition to treatments to TB patients, a major precaution against pulmonary TB is to vaccinate newborns (BCG). Drugs for TB mainly include rifampicin, isoniazid and streptomycin. They are known as first-line drugs because they are effective with fewer side effects. Drugs like kanamycin, ofloxacin, and levofloxacin are considered as second-line drugs. However, due to the high drug resistance of mycobacterium tuberculosis, patients are usually treated with a combination of first- and second-line drugs.
But even with higher BCG vaccination rates and increasing number of prevention and control measures of TB, TB incidence has risen again in recent years, especially in developing countries, due to various causes such as HIV/AIDS, alcoholism, drug abuse and the emergence of drug-resistant mycobacterium tuberculosis. It is estimated that the infection rate of mycobacterium tuberculosis in some developing countries is as high as 80%. In particular, with immune system destroyed by HIV, AIDS patients are more likely to be infected with mycobacterium tuberculosis and the infection can develop into active tuberculosis in a shorter period of time.
Therefore, we have to contact with TB patients properly, stay away from drugs and excessive drinking and live a healthy life.
Author: Yuan Qing
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