Today (24 March) is the 27th World TB Day.
According to the latest global tuberculosis report released by the World Health Organization in 2021, nearly 10 million new cases of tuberculosis and more than 1.4 million deaths will be reported globally in 2020.
In recent years, TB has been the number one cause of death from a single source of infection, and due to the impact of the COVID-19 pandemic, TB's ranking as the cause of death from a single infectious disease dropped to No. 2 in 2020, behind COVID-19.
1
Will it be infected if it is transmitted from 2.5 meters to a tuberculosis person?
Although tuberculosis and new crown pneumonia are both respiratory infectious diseases, there is a certain difference in the contagiousness of the two.
The new crown pneumonia has the characteristics of short incubation period, strong contagiousness, and infectious disease among asymptomatic infected people.
Different from the new crown pneumonia, tuberculosis is a chronic respiratory infectious disease, tuberculosis patients in the infectious period in the cough, talking, singing, sneezing, will produce a large number of microbus droplets containing Mycobacterium tuberculosis (that is, spit star), larger droplets will soon sink to the ground, difficult to be inhaled by surrounding contacts, only some small microbus droplets containing a small amount of Mycobacterium tuberculosis, will float in the air for a long time, float far, inhaled by close contacts around may lead to tuberculosis infection.
It can be seen that for respiratory infectious diseases such as tuberculosis, maintaining a social distance of about 1 meter and wearing masks can reduce the risk of transmission, and due to the defense mechanism of the human respiratory tract and the protective role of the immune system, not all close contacts will be infected.
Therefore, the online transmission of "2.5 meters away from the tuberculosis person will be infected" is not credible, maintain a good social protection distance.
2
Are all tuberculosis contagious?
Most of the onset of tuberculosis is slow, some patients have no obvious symptoms in the early stage, about 30% of tuberculosis patients do not have cough, sputum cough, hemoptysis, low-grade fever, night sweats and other typical symptoms when diagnosed, and this part of the patients are mainly found during imaging examination during physical examination.
As the lesion progresses, cough, sputum, sputum with blood or hemoptysis, some patients have recurrent symptoms of upper respiratory tract infections, systemic symptoms such as night sweats, fatigue, intermittent or persistent afternoon low fever, loss of appetite, weight loss and other symptoms may occur; female patients may be accompanied by menstrual disorders or amenorrhea. A small number of patients have a sudden onset of illness, with moderate or high fever, and some with symptoms such as varying degrees of dyspnea.
In addition, a special reminder is that not all patients with tuberculosis are contagious, and only patients with active tuberculosis who are in the infectious/bacterial phase are contagious.
According to statistics, a patient with active tuberculosis can infect about 10-15 people per year, and after infection with tuberculosis bacillus, it is not necessarily the disease, only about 5%-10% of infected people can progress to active tuberculosis in their lifetime.
Patients with active pulmonary tuberculosis have been standardized for about 1 month in anti-tuberculosis treatment, and their infectivity has also been greatly reduced.
Latent tuberculosis infection has not been reported to be contagious, but the risk of progression to active tb is higher in this population.
Since tuberculosis is mainly transmitted through respiratory droplets, patients with early tuberculosis who do not have cough and sputum coughing symptoms are also less contagious than patients with tuberculosis who have obvious coughing and sputum coughing symptoms.
Also, tuberculosis is preventable and treatable.
Isoniazid, rifampicin, ethambutol, and pyrazinamide are the first-line anti-TUBERCULO drugs of choice for the treatment of tuberculosis, usually using a combination of the above four drugs, and the course of treatment takes at least 6 months.
For patients with tuberculosis who are sensitive to first-line anti-tuberculosis drugs, the cure rate can reach more than 90% after regular and full medication.
Therefore, there is no need to panic too much about tuberculosis.
3
Have a meal with a tuberculosis person
Is it contagious?
Whether eating with tuberculosis people will be infected needs to be interpreted from three links: the source of infection, the transmission route and the susceptible population.
The first is the source of infection.
If the tuberculosis person has a long onset time, has obvious cough and sputum coughing symptoms, has a wide range of lung lesions, and has tuberculosis bacteria found on sputum examination, and has not undergone formal anti-tuberculosis treatment, it is more contagious. At this time, there is a risk of infection by being in close contact with it in the same confined space for a long time and without effective protective measures.
The second is the route of transmission.
Because tuberculosis is mainly transmitted by respiratory droplets, there is a risk of transmission in a confined environment with patients with active tuberculosis in the infectious period for a long time.
If the eating environment is relatively closed, the ventilation is not good, and the close contact with tuberculosis patients is long, the micronicle droplets containing Mycobacterium tuberculosis are easily inhaled by people eating at the same table, which may lead to tuberculosis infection.
The last link is the susceptible population.
The human respiratory tract has a certain defense mechanism, the immune system also has a certain protective effect, not all close contacts will be infected with tuberculosis, but the elderly with low immune function, young children, diabetes, AIDS patients, patients with immunosuppressants, long-term alcoholism, drug addicts, pneumoconiosis patients, etc. are at high risk of infection with tuberculosis, easy to infect and develop disease.
In summary, whether eating with tuberculosis people will be infected requires specific analysis of specific problems. Of course, if you find people with long-term obvious cough and sputum around you, remind them to seek medical treatment in time.
4
Someone around me has tuberculosis
What to do?
First of all, the possibility of infection can be analyzed with reference to the above description.
At the same time, the local CDC or community health service agency will conduct a follow-up survey of tuberculosis patients.
If it is judged to be a close connection of tuberculosis patients, health monitoring should be done in accordance with the notice of the staff, and if there is an abnormality, you can go to the regular tuberculosis designated hospital for chest imaging (X-ray or chest CT), PPD skin test or blood draw IGRA (γ interferon release test) test to check whether there is infection.
If a person is judged to be latently infected with tuberculosis, preventive treatment can be given under the guidance of medical personnel to reduce the risk of future disease.
When someone around you has tuberculosis:
When a tb patient is present in the home, especially a highly contagious bacterium excretor, it should be checked whether other members of the family are also infected with TB or whether they are the source of TB infection.
Especially in the family of children and the elderly, the body's resistance is poor, easy to contract tuberculosis.
Second, family members should urge tuberculosis patients to take medication on time and review it regularly.
Third, it is best for tuberculosis patients with bacterial discharge to live alone, and the room should often open windows for ventilation to keep the indoor air fresh; patients' clothes and bedding should be washed and dried frequently, and patients' tableware can be boiled and disinfected; patients should not spit on the ground, spit on paper and wrap them up and throw them away, and do not cough and laugh at others at close range to reduce the chance of infection.
Finally, pay attention to strengthening nutrition for patients to improve the body's resistance to disease.
At the same time, it is also necessary to give patients more care and care, not to discriminate, to help them lay down their burdens, and to actively cooperate with doctors to treat and restore health as soon as possible.
Source: Popular Science China (ID: Science_China)
Expert: Wang Wei, Zhejiang Provincial Center for Disease Control and Prevention, physician in charge
Chen Yuanyuan, Deputy Director of tuberculosis department of Zhejiang Tuberculosis Diagnosis and Treatment Center
Chen Bin, Chief Physician, Zhejiang Provincial Center for Disease Control and Prevention
Producer: Mou Yanqiu Huang Linhao
Editor: Dong Jingxue
Proofreader: Guiting