Tuberculosis has been widespread throughout human history for thousands of years, and at one time it was said that “nine out of ten diseases are consumption”. In the famous Chinese novel “Dream of the Red Chamber”, the reader is impressed by the beautiful and talented Lin Daiyu. In Cao Xueqin’s brilliant writing, we see the delicate, thin, frequent coughing and hemoptysis of Lin’s sister, the typical image of a tuberculosis patient. The Jia family’s good food and clothing failed to save the Lin sister, who was loved by many, from dying, and the horror of tuberculosis is thus evident. Scientific progress has made TB “9 out of 10” and “9 out of 10” a thing of the past, but as the number of TB patients around us decreases, some of our friends have the question “Has TB disappeared in China? has disappeared in China?” In response to similar questions, experts from the Beijing Chest Hospital/Beijing Institute of Tuberculosis and Thoracic Oncology, affiliated with Capital Medical University, have conducted a series of studies to answer questions about the characteristics of the TB epidemic in China, which have had a profound impact on guiding TB prevention and control. I. Characteristics of tuberculosis bacilli and tuberculosis make it extremely difficult to control tuberculosis In the thousands of years that tuberculosis has been rampant, people have never understood the causes of tuberculosis and have no way to treat or prevent it. It was not until March 24, 1882, that the German scientist Robert Koch reported at the Berlin Physiological Society that the cause of tuberculosis was unknown. This was a landmark day in the history of tuberculosis and a major turning point in the fight against tuberculosis. Robert Koch was also awarded the Nobel Prize in Physiology and Medicine in 1905 for his major achievements in tuberculosis research. We now know that Mycobacterium tuberculosis is surrounded by thick lipid, like a strong bulletproof vest, and is highly resistant to unfavorable conditions such as dryness and low temperatures, surviving up to 3 months in dark, humid environments, far longer than viruses and other bacteria. Moreover, tuberculosis bacteria is a kind of “cunning” bacteria, showing various growth states such as fast, slow and stationary, among which the slow-growing bacteria are difficult to be completely eliminated by drugs, relying mainly on an extended course of treatment to kill such bacteria, which is the main reason for the current anti-tuberculosis course of up to 6 months. Humans have now eradicated smallpox and basically controlled cholera and plague, but tuberculosis control is still difficult. The period from when a person is infected by a bacterium or virus to the onset of disease is called the incubation period. The incubation period for acute infectious diseases such as Ebola hemorrhagic fever generally does not exceed three weeks, while the incubation period for tuberculosis can be a lifetime. In this way, a person infected with TB bacteria at any time in a person’s life can develop TB disease. In addition, the course of acute infectious diseases is generally only a few months, while untreated tuberculosis patients can remain ill for decades, and an untreated infectious tuberculosis patient can infect 10-15 healthy people each year, and tuberculosis patients who do not receive timely and effective treatment may cause further spread of the disease. Because of the long incubation period and the long course of TB, TB is not easy to control, especially in China, a country with a large geographical area and huge differences in the level of medical care between regions. Second, the appearance of suspicious symptoms of tuberculosis should be screened in a timely manner. As the symptoms of coughing and coughing in patients with tuberculosis resemble those of respiratory infections, patients often think their discomfort is caused by colds and bronchitis, thus delaying diagnosis and treatment, causing further spread of the disease and increasing the risk of treatment failure. The key to controlling tuberculosis lies in the timely detection and treatment of infectious tuberculosis patients, and workers at tuberculosis control facilities are committed to detecting as many patients as possible through screening and reducing the spread of the disease without the patient’s knowledge. A good screening method should have the following characteristics:1 be simple, convenient, inexpensive, and easy to master and promote in primary care institutions;2 detect as many TB patients as possible and avoid missing cases. The Beijing Institute of Tuberculosis and Thoracic Oncology found that sputum TB bacilli and X-ray chest radiographs for patients with symptoms such as coughing and sputum for more than 2 weeks can improve the detection rate of TB patients. This diagnostic procedure, which is not only technically simple and easy to perform but also enables the detection of more TB patients, has led to the establishment of a TB screening model based on which is widely used for TB screening in people with suspicious symptoms. It is currently recommended in China that those who develop cough, cough sputum for more than two weeks or hemoptysis should be seen at a TB specialist hospital or TB clinic and undergo sputum TB bacilli and chest X-ray examination. The number of TB bacilli in the sputum of diagnosed TB patients can decrease by 80% after two weeks of anti-TB treatment, and the cure rate of first-time diagnosed TB patients exceeds 95% after standard treatment. Active detection of infectious TB patients not only reduces treatment failure, but also reduces disease transmission. Third, China has many TB patients and TB infections A team led by Prof. Hongzheng Duanmu of Beijing Institute of Tuberculosis and Thoracic Oncology organized a national TB epidemiological survey in 2000, which covered 31 provinces, municipalities and autonomous regions, 257 sampling sites, and as many as 360,000 people. The survey showed that the prevalence of active tuberculosis in China reached 367/100,000, in other words, there were 4.51 million active tuberculosis patients in China at that time, a level that was not only much higher than in countries or regions with good tuberculosis control, but also much higher than the world average. China is ranked by the World Health Organization as one of the 22 countries with a high burden of TB, with the second highest number of TB patients in the world, just below India. TB has not disappeared in China, and TB control will remain a long way off for quite some time. This survey also found that the TB infection rate in China is as high as 44.5%, with 550 million people infected. Although TB infection does not mean TB disease, about one in ten infected patients may develop active TB disease, especially in patients with combined diabetes and chronic renal insufficiency, and the likelihood of developing active TB disease is 2-3 times higher than in those without combined underlying disease. The risk of developing active TB disease is higher in patients with HIV infection, organ transplantation, and glucocorticoid use. A large population of TB infections can lead to new cases of TB over a long period of time. However, there is no need to worry about TB infection: TB infected people are not patients, they do not have to be treated, and they do not infect others, and most infected people do not develop TB disease. Fourth, China has many drug-resistant tuberculosis Some friends may ask: Is it possible to control tuberculosis with anti-tuberculosis drugs? In the 1980s, after the combination of isoniazid, rifampin, ethambutol and pyrazinamide, the cure rate of tuberculosis once reached 95%, but now tuberculosis is back, and one of the important reasons is the emergence of drug-resistant tuberculosis. Drug-resistant TB can be due to both infection with drug-resistant TB bacteria and inappropriate treatment. Anti-tuberculosis drugs are like precision-guided missiles that attack different targets of the bacteria, but drug-resistant bacteria change their structure so that the missiles do not find their targets, making the drugs “impossible”. The treatment of diseases caused by drug-resistant bacteria is not only long and costly, but also has a low cure rate. A study of 3,929 strains of Mycobacterium tuberculosis in 31 provinces, autonomous regions and municipalities across China by a team led by Professors Xu Shaofa and Zhao Yanlin at Beijing Chest Hospital, affiliated with the Capital Medical University, showed that one quarter of the tuberculosis bacilli were resistant to isoniazid and/or rifampin, making the prevalence of drug-resistant tuberculosis in China a grim reality. It is calculated that 110,000 new cases of multidrug-resistant TB (resistant to both isoniazid and rifampicin) occur in China each year, in other words, one case of multidrug-resistant TB occurs every 5 minutes, and it is particularly frightening that three-quarters of multidrug-resistant TB patients are infected with drug-resistant TB bacteria, indicating that the mode of transmission of drug-resistant TB in China is dominated by direct infection with drug-resistant bacteria. The rapid diagnosis, treatment and management of drug-resistant TB patients should be strengthened to avoid further spread of drug-resistant TB epidemics. The tuberculosis pandemic that occurred during the industrial revolution in Europe in the 18th century was called the “white plague” and was once a cause for alarm. As scientists understand the nature of tuberculosis, there will not be another worldwide tuberculosis pandemic. At the present stage, with the participation of the whole society, active detection and rational treatment of tuberculosis, we will eventually eliminate this disease that has long been a threat to humanity.