Tuberculosis - Find a Doctor and Get Information

Tuberculosis is caused by bacteria from the Mycobacteriaceae family. In addition to the most common pathogen, Mycobacterium tuberculosis, this family also includes the species Mycobacterium bovis and Mycobacterium africanum.

Transmission usually occurs through people suffering from active pulmonary tuberculosis. In this case, the tuberculosis lesion in the lung tissue is connected to the airways. The infected person releases the pathogens into the environment through exhaled air.

Infection occurs via the airborne route. This means the infection is transmitted through tiny droplets produced when coughing, speaking, or sneezing.

Whether infection occurs depends on:

• The duration of contact with the infected person
• Frequency of contact with the infected person
• The closeness of contact with the infected person
• The amount of the pathogen inhaled
• The health status of the exposed person

In principle, tuberculosis infection is also possible through the consumption of unpasteurized milk from infected cattle.

The cattle population in Germany and Central Europe is largely free of tuberculosis, so the risk of infection is very low.

In the first stage of tuberculosis infection—the latent tuberculosis stage—no symptoms are present.

The tuberculosis pathogens are surrounded by cells of the immune system, known as T-lymphocytes.

This leads to the formation of inflammatory, nodular lesions known as tubercles or granulomas.

In more than 80 percent of all cases, these tubercles are located in the lungs. When the adjacent lymph nodes are involved, doctors also refer to this as a primary complex.

Most tuberculosis patients still show no symptoms of the disease in this second stage. However, some patients suffer from a mild fever and a dry cough or a cough with a small amount of yellowish-green sputum.

It is also not uncommon for so-called “B symptoms” to appear, including night sweats, loss of appetite, and weight loss.

Severe cases involving coughing up blood (hemoptysis) and chest pain occur only in patients with a weakened immune system.

In people with a healthy immune system, the inflammatory foci become encapsulated after one to two weeks. At this point, the tuberculosis is considered latent, posing no risk of transmission.

However, the pathogens are merely contained and have not completely disappeared. In the event of immunodeficiency, the inflammatory foci can rupture, allowing the pathogens to be released into the environment via the respiratory tract.

This contagious form of the disease is called “active tuberculosis.” As part of this reactivation, the mycobacteria can spread throughout the body and manifest in other organs.

In addition to pulmonary tuberculosis, there are other forms of the disease, such as:

• Cutaneous tuberculosis
• Tuberculosis of the thoracic and lumbar spine
• Tuberculous meningitis involving the brain or meninges
• Urogenital tuberculosis of the kidneys, urinary tract, adrenal glands, and genital tract
• Intestinal tuberculosis
• Tuberculosis of the teeth

Tuberculosis (consumption) is the world’s most common fatal infectious disease in humans © Henrie / Fotolia

An initial suspected diagnosis is often made based on the medical history (anamnesis) and physical examination alone.

In particular, contact with infected individuals, as well as previous suspicious symptoms or a known initial infection, can be clear indicators.

However, to confirm the diagnosis, detection of the pathogen is essential. To do this, doctors collect pathogen-containing material from saliva, gastric juice, bronchial secretions, or urine and have it examined in a microbiology laboratory.

Ziehl-Neelsen staining can be used to detect mycobacteria. In this procedure, acid-fast bacteria are stained with a special solution, whereas other bacteria remain unstained.

However, the detection limit is very high, so a large number of bacteria must be present to reliably detect the pathogen.

A negative result therefore does not definitively rule out a tuberculosis infection. A positive result is also not considered conclusive.

A positive bacterial culture with an antibiogram, on the other hand, is proof of a tuberculosis infection.

In addition, another molecular biology method can be used to confirm the diagnosis: the polymerase chain reaction (PCR).

Doctors always treat active tuberculosis with antibiotics that are effective against mycobacteria. These are also referred to as antituberculosis drugs.

To prevent the development of resistance, doctors prescribe a combination of several effective antibiotics.

These include:

• Isoniazid
• Pyrazinamide
• Ethambutol
• Streptomycin
• Rifampicin

Tuberculosis patients generally need to take these antibiotics for up to six months.

Even if the infection no longer causes any symptoms in the meantime, you must continue taking the medication. Stopping treatment prematurely carries the risk of both tuberculosis reactivation and the development of resistance.

In addition to the primary treatment, symptomatic treatment with medications to relieve the unpleasant cough may be prescribed.

Even if the treatment proceeds without complications, patients should undergo a medical examination every two years to rule out reinfection.

The course and prognosis of tuberculosis depend on several factors.

First, the patient’s immune status influences the prognosis. People with a weakened immune system may develop what is known as miliary tuberculosis. In this condition, small foci of infection form in the lungs and various other organs.

Typical symptoms include severe malaise, high fever, headaches, and shortness of breath.

If left untreated, nearly all patients with miliary tuberculosis die. Even with adequate treatment, the case-fatality rate remains at ten percent.

Another feared complication that significantly worsens the prognosis is tuberculous meningitis.

Although it is extremely rare, accounting for less than one percent of reported tuberculosis cases in Germany, it is usually fatal.

Furthermore, the timing of detection influences the course of the disease. The earlier doctors make the diagnosis, the better the prognosis.