What is tuberculosis?

I believe everyone knows that tuberculosis is a disease that is difficult to cure. In the early years, tuberculosis was even considered an incurable disease. Generally, after getting tuberculosis, what everyone needs to pay attention to is reasonable control and choosing standardized methods to treat tuberculosis. Tuberculosis has an epidemiological history, so it is a very contagious disease with a wide range of transmission routes.

Mycobacterium tuberculosis is a genus of mycobacteria that was discovered in 1882 by German microbiologist Robert Koch. Under a microscope, tuberculosis bacteria appear as slender, slightly curved or straight rods, measuring (0.3~0.6 μm) x (1~4 μm). They are scattered individually, in V or Y shapes, or arranged in strips or short chains. Mycobacterium tuberculosis is an obligate aerobic bacterium that grows very slowly. On solid culture medium, the generation time of Mycobacterium tuberculosis is 18 to 20 hours, and the culture time requires more than 8 days to 8 weeks. The colonies are rough on most media. It is resistant to acid and acid alcohol decolorization, so it is also called acid-fast bacillus. Mycobacterium tuberculosis actually includes human, bovine, mouse and African types, which are the Mycobacterium tuberculosis complex, among which human, bovine and African types are pathogenic bacteria.

Epidemiology

1. Source of infection: The main source of tuberculosis infection is patients with pulmonary tuberculosis with positive sputum smear or culture, among which smear-positive pulmonary tuberculosis is the most contagious.

2. Transmission route: Mycobacterium tuberculosis is mainly transmitted through the respiratory tract. When patients with active pulmonary tuberculosis cough, sneeze or talk loudly, droplet nuclei with a single tuberculosis bacterium as the core will be formed and suspended in the air, thereby infecting new hosts. In addition, the tuberculosis bacteria coughed up by patients dry and attach to the dust, forming bacterial dust, which can also invade the human body and cause infection. Transmission through the digestive tract, urogenital system, and skin is extremely rare.