But tuberculosis is not just a disease of the past. While the risk is not the same everywhere, TB remains a major global health issue and continues to cause serious illness and death every year. The myths surrounding it today may be less fairy-tale-like, but many of the ideas people have about the disease are still outdated. So what is still true, and what is a myth?

What is tuberculosis?

Tuberculosis is an infectious disease caused by bacteria, most commonly Mycobacterium tuberculosis. It usually affects the lungs, but it can also affect other parts of the body. TB is an airborne disease: it spreads through the air when a person with active TB disease of the lungs or throat coughs, speaks, sings, or sneezes. In 2024, an estimated 10.7 million people developed TB and around 1.23 million people died from it worldwide, underlining that TB remains a major global health issue. At the same time, TB is both preventable and curable when it is diagnosed early and treated correctly.

Common symptoms of active TB include a persistent cough, fever, fatigue, weight loss, and night sweats. Some people may also experience loss of appetite, chest pain, or coughing up blood. If left untreated, TB can become severe and potentially life-threatening.

After infection, there are generally two possible outcomes:

• Inactive TB, also called latent TB infection (LTBI): the immune system is able to contain the bacteria, so the person does not feel sick and has no symptoms. People with latent TB infection are not infectious. However, without treatment, latent TB can later develop into active TB disease, sometimes months or even years after the initial infection, especially if the immune system becomes weakened.
• Active TB disease: the bacteria multiply and cause illness. If the disease affects the lungs or throat, the person may also spread TB to others. Active TB can develop soon after infection or much later, especially if the immune system becomes weakened. People with active TB usually have symptoms.

How quickly TB disease develops depends in part on how well the body is able to keep the bacteria under control. People with weakened immune systems are at greater risk of developing active TB, including those living with HIV and people with certain other health conditions.

Who is most at risk and where?

The risk of tuberculosis depends mainly on two factors: exposure and immune vulnerability. TB is more likely to spread after close and prolonged contact with a person who has infectious TB, especially in indoor spaces with poor ventilation. People with weakened immune systems are more likely to develop active TB disease after infection. This includes, for example, young children under 5 years of age, older adults, people living with HIV/AIDS, people affected by malnutrition, and those with certain chronic diseases such as diabetes mellitus.

TB occurs worldwide, but the burden is not evenly distributed. In 2024, eight countries accounted for about two thirds of all people who fell ill with TB: India, Indonesia, the Philippines, China, Pakistan, Nigeria, the Democratic Republic of the Congo, and Bangladesh. Overall, the largest number of new TB cases occurred in the WHO South-East Asia Region, followed by the Western Pacific and African regions.

Is TB still a risk today?

Tuberculosis is still a major global health threat today. It remains among the top 10 causes of death worldwide and is also the leading cause of death among people living with HIV. In 2024, an estimated 10.7 million people developed TB worldwide.

In Switzerland and other countries in Central Europe, TB is much less common than in other parts of the world. But lower incidence does not mean that TB has disappeared. In Switzerland, around 550 people are diagnosed with tuberculosis each year. Most cases occur in people born abroad, particularly in those coming from countries with a higher TB burden. Among people born in Switzerland, those affected are more often older adults who were infected earlier in life, when tuberculosis was still more widespread in the country.

The BCG vaccine (Bacille Calmette-Guérin vaccine), the main vaccine used against tuberculosis, is not part of routine vaccination recommendations for people permanently living in Switzerland. It may still be considered in specific situations, especially for infants who will spend extended time in countries with a high TB burden. If vaccination is recommended, it is often arranged in the destination country, as TB vaccination is not available in Switzerland.

How is TB diagnosed and treated today?

Diagnosing tuberculosis usually involves a combination of medical history, physical examination, imaging such as a chest X-ray, and laboratory testing. If active TB is suspected, sputum (a mixture of saliva and mucus that is coughed up from the respiratory tract) or other samples can be examined to detect the bacteria.

To test for TB infection, either a blood test or a skin test may be used. However, these tests alone cannot distinguish between latent TB infection and active TB disease. Further evaluation is needed to tell the difference.

At the Travel Clinic UZH, the Quantiferon® test is offered. This is a modern TB blood test used to detect infection with Mycobacterium tuberculosis. It can be booked through our appointment booking system under either “Routine Vaccination Check” or “Pre-Travel Medical Consultation”. Returned travelers can contact us directly by phone or email to arrange an appointment.

Active TB disease must be treated with a combination of antibiotics, on average for at least six months. Several drugs are used to reduce the risk of relapse and resistance. Strict adherence to the treatment schedule is essential, because interruptions, incorrect dosing, or incomplete treatment can make therapy less effective and contribute to drug resistance.

Tuberculosis: modern facts vs myths

Tuberculosis has been around for centuries, and many of the ideas people still hold about it come from the past. But modern medicine has changed our understanding of how TB spreads, how it is treated, and who is most at risk. That makes it worth separating fact from fiction to build a clearer and more useful understanding of TB today.

Myth: TB is a disease of the past.

Although TB incidence fell dramatically in many countries during the 20th century, tuberculosis is far from gone. In 2024, an estimated 10.7 million people developed TB and around 1.23 million people died from it worldwide. TB therefore remains one of the most important infectious diseases globally.

Myth: You can catch TB from dirty surfaces, dishes, or touching.

Not true. Tuberculosis is primarily an airborne disease. It spreads through the air when a person with infectious TB of the lungs or throat coughs, speaks, sings, or sneezes, and another person inhales the bacteria.

Myth: Latent TB is contagious.

This is a common misunderstanding. People with latent TB infection do carry the bacteria, but they do not feel sick and cannot spread TB to others. Only active TB disease in certain forms, especially pulmonary TB, can be infectious.

Myth: If you’re vaccinated, you’re protected for life.

The vaccine can help protect young children against severe forms of TB; however, it does not provide lifelong, complete protection against all forms of tuberculosis, and it has not eliminated adult pulmonary TB transmission. Even vaccinated people should still take symptoms and possible exposure seriously.

Myth: In low-incidence countries, TB is basically ‘gone’.

TB is less common in many high-income countries, but it has not disappeared. In the EU/EEA, 38,993 TB cases were reported in 2023. TB therefore remains a relevant public health issue even in lower-incidence settings, particularly among vulnerable groups.

More than a historical disease

Tuberculosis may feel like a disease from another era, but it is still very much part of today’s global health reality. Knowing how TB spreads, who is most at risk, and which myths no longer hold true helps create a more realistic and useful understanding of the disease. TB is preventable and treatable, but only if prevention strategies are taken seriously, active cases are diagnosed early, and patients complete their treatment as prescribed.

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