How far are we from ending TB? (Health Express (Stop 113))

When it comes to tuberculosis, many people think it has been eradicated. In fact, this ancient disease has never been far from human society. What is the current situation of tuberculosis epidemic in China? How far are we from ending TB? What are the difficulties in stopping TB?

To this end, our reporter interviewed Li Liang, deputy director of the Tuberculosis Prevention and Control Clinical Center of the Chinese Center for Disease Control and Prevention and vice president of Beijing Chest Hospital.

"Familiar strangers"

As one of the oldest infectious diseases in the world, tuberculosis is also known as the "white plague" and "tuberculosis". Tuberculosis is caused by Mycobacterium tuberculosis and can invade various organs of the human body, with tuberculosis being the most common. In the West, tuberculosis was once called the "head of death", and in China there was also a saying of "ten tuberculosis and nine deaths".

On March 1882, 3, German scientist Robert Koch announced the discovery of the pathogenic bacteria of tuberculosis, and the prevention and control of tuberculosis ushered in the dawn. With the emergence of streptomycin, isoniazid and rifampicin anti-tuberculosis drugs in the 24s of the 20th century, the history of "ten tuberculosis and nine deaths" has been completely reversed, and tuberculosis is no longer an incurable disease, and even disappeared for a while. In the late 50s of the 20th century, TB resurgent globally with factors such as increased global population movements, the emergence of drug-resistant strains and the AIDS epidemic. In 90, the World Health Organization declared a "state of emergency" for tuberculosis based on the incidence of tuberculosis and other circumstances.

"Some people have not heard of TB for many years and think that TB has been eradicated, but in fact, TB is not far away, it can be said to be a 'familiar stranger'." Li Liang said that tuberculosis is still a global public health problem that seriously endangers public health.

The World Health Organization's Global TB Report 2022 estimates that global TB control has saved an estimated 2000 million lives since 7400, but there were still about 2021.1060 million new TB cases and 160.90 million deaths from TB globally in 2021. In China, significant progress has been made in tuberculosis prevention and control, and the cure rate of tuberculosis patients has remained above 78% in recent years, but as a country with a high burden of tuberculosis, China's tuberculosis prevention and control situation is still grim, and the number of new tuberculosis cases in China in <> is estimated to be <>,<>, second only to India and Indonesia.

Controlling and eventually eliminating TB is a shared global responsibility. In 2014, the World Health Organization proposed the "End TB Strategy" and set 2035 targets: a 2015% reduction in TB incidence, a 90% reduction in deaths, and a reduction in TB incidence below 95 per 10,10 compared to 2015. In 2030, the United Nations Sustainable Development Goals 2030 called for ending the TB epidemic by <>.

"One of the core indicators of TB prevention and control is incidence." Li Liang said, "If the incidence of an infectious disease drops below 10/10,2021, we can consider that the epidemic of the infectious disease has ended." China's estimated incidence rate of tuberculosis in 55 is 10/10,10, and to drop below <>/<>,<>, innovative means and comprehensive measures are urgently needed to strongly promote tuberculosis prevention and control. ”

The TB epidemic has a long way to go

What are the difficulties in ending the TB epidemic?

Li Liang said that in order to end the tuberculosis epidemic, three conditions are needed: good vaccines, new diagnostic tools and effective clinical drugs.

In terms of vaccines, Li Liang introduced that at present, human beings mainly rely on the BCG vaccine born in 1921 to prevent tuberculosis. BCG is relatively effective in preventing severe tuberculosis in children, but has limited effectiveness in preventing tuberculosis, especially in adults. "BCG has played a huge role in preventing the development of infectious diseases, but it is not perfect, it is not 100% protective like the smallpox vaccine, so people will not get sick again for a lifetime." Li Liang said that in order to overcome the shortcomings of insufficient protection of BCG, the world is accelerating the development of new tuberculosis vaccines, and some vaccine candidates have entered the clinical trial stage and made some progress.

In terms of new diagnostic tools, Li Liang introduced that there are two main traditional tuberculosis diagnosis methods: sputum culture and X-ray. These two detection methods have been used clinically for hundreds of years, and have the limitations of long diagnosis time and low detection rate. Good diagnostic tools detect TB early or asymptomatically. At present, some progress has been made in tuberculosis detection methods, such as the rapid development of molecular biology, and new diagnostic tools are more sensitive, convenient and efficient, but due to the high price, they have not been popularized in all medical institutions, and it is hoped that these relatively fast and convenient diagnostic tools can be popularized to the grassroots level as soon as possible.

In terms of clinical drugs, Li Liang introduced that the ideal anti-tuberculosis drug should allow patients to heal within days or weeks after taking the drug. However, the field of tuberculosis treatment has always faced an embarrassment: tuberculosis bacteria have "evolved" for thousands of years and are still constantly updated, but anti-tuberculosis drugs are basically still decades ago, and only 3 new drugs have been developed in the past half century, and drug access is low. "The development of new drugs often takes more than 10 years and requires a lot of resources, and countries with these abundant resources have relatively few patients, and there is a lack of motivation for enterprise research and development, while the countries that need new TB drugs the most face the dilemma of limited resources." Li Liang said that in recent years, China has invested more and more in the prevention and treatment of tuberculosis, and many new drug projects have also entered the clinical stage. Tuberculosis is a worldwide infectious disease, which requires international cooperation and joint research, increasing the research and development of drugs and vaccines and the application of new technologies.

"We have a long way to go to end the TB epidemic." Li Liang said, "At present, we are still far from the ideal state in terms of vaccines, new diagnostic tools and clinical drugs, and there is still a lot of work to be done. ”

It is necessary to form an atmosphere in which the whole society participates in prevention and treatment

China has always attached great importance to tuberculosis prevention and control, incorporated it into the Healthy China Strategy, continuously improved the level of protection, carried out multi-sectoral cooperation, called for the participation of the whole society, and actively promoted new diagnostic technologies, new treatment options and new management tools. In recent years, intensive deployment has begun at the national level.

"The coronavirus pandemic has raised awareness of respiratory infectious diseases." Li Liang said that the good hygiene habits formed by people in the prevention and control of the new crown, such as wearing masks, washing hands frequently, ventilating more, and paying attention to cough etiquette, are also conducive to the prevention of tuberculosis. But at the same time, the number of tuberculosis patients reported in China in 2020 and 2021 has decreased significantly. Experience tells us that this is not the case, but rather suggests an increase in the number of undiagnosed and untreated TB patients, which may lead to more community-transmitted infections. ”

In the prevention and control of infectious diseases, timely and effective cutting off transmission routes and controlling the sources of infection are important methods to protect vulnerable people and curb the spread of diseases. "However, one of the difficulties in tuberculosis prevention and control is that its onset is hidden, and the incubation period of tuberculosis is a short few months, long years or even more than ten years, which brings great challenges to tuberculosis prevention and control, so our prevention and control strategy should change from passive detection to active attack." Li Liang said that at present, tuberculosis is mostly symptomatic, but studies have shown that nearly half of tuberculosis patients are asymptomatic, so more latent tuberculosis should be found through health examination, "China's population base is large, full screening is difficult to achieve, but high-risk groups can be screened, such as the elderly, diabetics, AIDS patients, transplant patients, etc." ”

"Although TB currently advocates non-hospitalization, in fact, if isolation of patients with infectious diseases is not in place, it is easy to expand transmission. In the future, the isolation and treatment of tuberculosis patients can be further done to reduce the risk of disease spread. Li Liang believes that the management of tuberculosis patients is very important, Mycobacterium tuberculosis is a bacterium that is easy to develop drug resistance, only reasonable and regular drug use can effectively kill tuberculosis bacteria, private drug discontinuation/intermittent medication will not only lead to treatment failure, recurrence, and may even produce drug resistance. Ordinary tuberculosis will be cured in about 6 months, and once it becomes drug-resistant TB, the retreatment time will be longer (generally 18-24 months), the treatment is more difficult, the treatment cost will be more than 10 times higher than that of ordinary tuberculosis, and the cure rate is lower. At the same time, once drug-resistant TB is transmitted to others, the infected person will also become drug-resistant TB after the disease occurs.

"Combined with clinical experience, in recent years, patients with difficult and severe tuberculosis have some new characteristics in the diagnosis and treatment." Li Liang introduced that the age of onset of tuberculosis patients is gradually increasing, and outpatient or inpatient patients aged 80 or 90 are very common; The proportion of tuberculosis patients with comorbidities has increased, and many patients have common diseases such as diabetes, hypertension, and heart disease, making treatment more difficult. "Older people are at high risk of developing TB." Li Liang said that it is recommended that the elderly do chest x-ray or CT once a year to screen for tuberculosis and achieve early detection, early diagnosis and early treatment.

Li Liang said that to end tuberculosis, it is also necessary to mobilize the strength of the whole society and form an atmosphere for the whole society to participate in prevention and treatment, "Some people do not have enough understanding of tuberculosis and lack vigilance, and should continue to popularize tuberculosis disease information, harm and prevention and treatment knowledge to everyone." ”

Further reading

How much do you know about tuberculosis?

What is TB?

Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis infection that can occur anywhere on the body except hair, nails and teeth, most commonly in the lungs, called tuberculosis, followed by tuberculous pleurisy, lymph node tuberculosis, bone tuberculosis, tuberculous meningitis, etc.

How is tuberculosis transmitted?

Tuberculosis is a respiratory infectious disease. People with tuberculosis spread tuberculosis bacteria into the air by coughing, coughing up sputum, and sneezing, and healthy people can be infected by inhaling droplets with tuberculosis bacteria.

People who live with tuberculosis patients, work and study in the same room are close contacts of tuberculosis patients, may be infected with tuberculosis bacteria, and should go to the hospital in time to check and exclude.

What are the main symptoms of tuberculosis?

Cough, sputum production for more than 2 weeks, hemoptysis or blood in sputum are the main local symptoms of tuberculosis. In addition, chest tightness, chest pain, low-grade afternoon fever, night sweats, general weakness, loss of appetite, or weight loss are also common systemic symptoms of tuberculosis.

Who is vulnerable to TB?

All populations are susceptible, with the following groups at high risk of infection: close contacts of people with tuberculosis; Infants, teenagers, students, seniors aged 60 and above; people living with HIV; long-term users of diabetes, silicosis, glucocorticoids and other immunosuppressants; malnourished, long-term alcoholics; Cirrhosis, after gastrectomy, after jejunosomoparastomy; Renal insufficiency, hemodialysis; Malignant tumors, psychopaths, etc.

Where should I see a doctor if I suspect tuberculosis?

If cough or sputum is coughed up for more than 2 weeks, tuberculosis should be suspected, and the local tuberculosis designated medical institution should be treated in time.

Is tuberculosis cured?

As long as ordinary pulmonary tuberculosis adheres to the whole process of standardized treatment, the successful treatment rate is more than 90%. If the treatment is not standardized or unreasonable, it is easy to lead to treatment failure and even drug resistance. The successful treatment rate of drug-resistant tuberculosis is low, only about 60%, and the treatment cost is high, generally costing 20,30-<>,<> yuan.

Is tuberculosis hereditary?

Tuberculosis is an infectious disease rather than a hereditary disease and is not passed on to the next generation. However, during the infectious period of tuberculosis, it can be transmitted through the air and can be easily transmitted to other family members.

What should tuberculosis patients pay attention to?

When coughing or sneezing, avoid others and cover your mouth and nose; Do not spit, spit sputum in a covered spittoon with disinfectant, and when it is inconvenient, you can spit it in disinfectant wipes or sealed sputum bags; Try not to go to crowded public places, if you must go, you should wear a mask; Patients with tuberculosis treated at home should try to live in separate rooms from others, keep the room ventilated, wear masks, and avoid family members being infected.

(People's Daily Overseas Edition, Wang Meihua)