Daily Science Popularization丨Experts say losing weight increases the risk of tuberculosis. I was so scared that I quickly bought a Big Mac to calm my nerves.

#Low-weight people are at high risk of tuberculosis#

Many people think that people with low weight or children with low weight are more likely to get tuberculosis when they see this topic. Some even say #people who lose weight have an increased risk of tuberculosis#, but the former is suspected of being exaggerated and there is no evidence for the latter.

Next, let’s look at the relationship between tuberculosis and weight, and by the way, talk about vaccines (the situation with vaccines is actually very negative).

Tuberculosis is not just pulmonary tuberculosis

Many people understand tuberculosis as pulmonary tuberculosis, but in fact the two are not the same.

Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis . Most people have no symptoms, but after symptoms appear, the lesions may appear in the lungs (pulmonary tuberculosis) or other parts of the body (extrapulmonary tuberculosis), and there is even " urogenital tuberculosis ".

Miliary tuberculosis, picture from purchase

The more serious type is "miliary tuberculosis", which may cause lymphadenopathy, hepatosplenomegaly, pancreatitis, etc. Patients who do not receive timely treatment will almost certainly die. Even with timely treatment, the mortality rate may be as high as 30%.

If left untreated, more than half of people with active TB will die.

Tuberculosis and weight linked

In fact, losing weight does not cause tuberculosis. Instead, tuberculosis causes weight loss.

In fact, many official platforms are saying that " people who lose weight have an increased risk of tuberculosis ", but in fact this is most likely a translation problem or an extended personal understanding. Perhaps because tuberculosis can cause weight loss (reduce weight, which can also be translated as "lose weight"), it has been misunderstood, but there is indeed no direct evidence that losing weight will increase the risk of tuberculosis.

Image source: DOI: 10.1038/s41598-022-20550-8

Low weight is indeed a risk factor for tuberculosis. Studies have found that subjects with mild (17.0≤BMI<18.5), moderate (16.0≤BMI<17.0) and severe (BMI<16.0) emaciation have a 2.0, 2.5 and 2.8 times increased risk of tuberculosis, respectively. Therefore, the real risk is not weight loss but low weight.

By the way, although obese and overweight people have a lower risk of tuberculosis than people of normal weight, they have a higher risk of "other health problems", so there is nothing to be happy about for you if you are fat.

These are the factors that are truly dangerous.

As an infectious disease, the core risk factor for tuberculosis is contact with infectious sources.

Risk of infection: Long-term and frequent contact with tuberculosis patients increases the risk of infection. If the patient is not treated, he or she may infect 15 or more people. Therefore, isolation treatment is the best way for patients with active tuberculosis to protect themselves and others.

Tobacco harm, picture from purchase

Risk of disease: Many people are asymptomatic after infection, but there are many risk factors that cause asymptomatic infection to turn into active tuberculosis, including HIV infection, drugs such as corticosteroids, diabetes, smoking, silicosis, etc., which can increase the risk of active tuberculosis several times!

In summary, low body weight is only one of the risk factors that increases the risk of asymptomatic infection turning into active TB; other risk factors (such as smoking) are more common.

Vaccines and vaccines under development

So far, the only truly effective vaccine is BCG, which has been invented more than 100 years ago.

The French doctor Albert Calmette and veterinarian Camille Guérin prepared the vaccine by passage the strain 239 times. The vaccine was also shown to reduce the risk of infection and development of active tuberculosis.

However, due to different disease burdens and research methods in different study areas, the effectiveness of BCG varies greatly. Some studies have not even found that BCG has a protective effect against tuberculosis, and its effectiveness will decrease over time.

BCG, source:

You know, since 2000, global tuberculosis prevention and control efforts have saved "about 74 million" lives, but about "1.6 million people" still died of tuberculosis in the world in 2021. In 2022, my country reported a total of "600,575 confirmed cases" and "2,919 deaths", even though very strict non-drug intervention measures were maintained during the COVID-19 pandemic.

This is also why the world is still actively promoting the research and development of tuberculosis vaccines. Many scientific research institutions in my country are also actively promoting the development of such vaccines, but so far no effective new vaccine has been approved. We can only look forward to better vaccines arriving as soon as possible.

Non-pharmacological interventions

The most important non-drug intervention measure is timely management of patients, including isolation (and timely medication, of course). Of course, some incentives are also needed to ensure compliance when necessary.

Tuberculosis medication, picture from purchase

In addition, preventing patients from spitting and paying attention to hand hygiene can also control the spread of the disease. However, these two points seem to be increasingly forgotten, so it is necessary to continuously consolidate good hygiene habits, which is of great public health significance for many infectious diseases including tuberculosis.

The last step is to control risk factors, including improving the nutritional intake of malnourished people, controlling smoking, and avoiding occupational diseases (mainly pneumoconiosis).

May the world be free of epidemics

=Pill=

Disclaimer: This article was created out of personal interest, only to help more ordinary people have a clearer understanding of vaccines. The content and views do not represent any organization, unit, or institution, and it has not accepted any form of sponsorship. All pictures are from public online platforms or depositphotos platforms that have paid for personal use rights. If the content is incorrect, please criticize yourself more (not).