What is disseminated tuberculosis?
Disseminated tuberculosis, also known as widespread tuberculosis, is a contagious infection in which a tuberculosis infection has spread from the lungs to other parts of the body, with multiple organs affected. Disseminated tuberculosis can occur within weeks of infection with tuberculosis or years afterwards.
The diagnosis of this form of TB involves taking a sample from the organ, that is believed to be affected, to prove the presence of an infection.
The treatment of disseminated tuberculosis usually involves taking a combination of antibiotics for 6 to 12 months. Most people recover well, although it does take time for the symptoms to improve. People who may be experiencing symptoms linked to disseminated tuberculosis can use the free Ada app to carry out a symptom assessment.
Good to know: The term miliary TB is used by some interchangeably with disseminated TB. However, miliary TB in fact refers more specifically to disseminated TB which presents with a millet-seed-like appearance on a chest x-ray, when the disease is spread by blood throughout the lungs (see FAQs).
Symptoms depend upon the organ system infected with the bacteria. Common general symptoms of tuberculosis include:
- Night sweats
- Malaise, i.e. feeling generally unwell
- Joint pain
- Weight loss
- Pale skin due to anemia
- Swollen glands
- A cough and shortness of breath
- Skin rashes
Less common symptoms that may be related to disseminated tuberculosis include:
- Bone pain
- Abdominal pain
- Blood in the urine
People who may be experiencing symptoms linked to disseminated tuberculosis can use the free Ada app to carry out a symptom assessment.
Tuberculosis (TB) is very infectious. The bacterium that causes tuberculosis, Mycobacterium tuberculosis, is spread through the air and via droplets from the mouth or throat of person infected with the pathogen. Infectious patients cough up large numbers of mycobacteria, which can survive on objects outside of the body for a long time.
Tuberculosis is usually contained in the lung by the formation of small granulomas, a mass of tissue that forms in response to infection or inflammation. These are structures created by the body to contain the mycobacterium. In such a case, the condition is known as primary or pulmonary tuberculosis.
Occasionally, normally in people with a severely damaged immune system, granuloma formation is impaired, and mycobacteria can spread through the blood or lymph system and infect other parts of the body. When this occurs, it is called disseminated tuberculosis.
Common locations for this to occur include:
- Central nervous system
- Adrenal glands
- Choroid, a structure within the eye
Risk factors for catching primary TB include:
- Being around people who have the condition
- Living in crowded or unclean conditions
- Having poor nutrition
Most people with tuberculosis in the US will not develop disseminated tuberculosis, as the immune system is often able to contain the primary infection. Risk factors that may increase the risk of developing disseminated tuberculosis may include:
- Living in areas where there is not good access to health care
- Not being well nourished
- Living in crowded conditions
- Having a weakened immune system, especially among people with HIV
- Being older than 65 or an infant
The diagnosis of disseminated tuberculosis can be difficult. Although the diagnosis may be suspected based on the symptoms, especially in a person who is at high risk of tuberculosis, it can only be confirmed with tests. Often, several tests are needed. These may include:
- A computerized tomography (CT) scan, magnetic resonance imaging (MRI) scan or ultrasound to look for TB in internal organs
- Taking a sample of the affected part of the body and testing it for the presence of the bacteria, such as from urine, the lymph glands near the skin, spinal fluid or the lung.
- An examination of the inside of the body with an endoscope – a long, thin, flexible tube with a light and camera at one end – which is inserted through a natural opening, such as the mouth, or through a small cut made in the skin
- A lumbar puncture, in which a small sample of cerebrospinal fluid is taken from the base of the spine
- A chest X-ray to look for tuberculosis infection in the lungs
- A skin, urine or blood test for the presence of antibodies to TB bacteria, which indicates exposure to it in the past
Good to know: People with suspected disseminated TB may be offered an HIV test because people with HIV are much more likely to develop disseminated TB. Treatment may be needed for both conditions.
Disseminated tuberculosis is treated with a combination of antibiotics. This is the same treatment for tuberculosis in the lungs, but disseminated TB usually needs a longer course of antibiotics. It may take 6 to 12 months to completely treat the infection.
It is very important to take TB medicines as instructed, otherwise the infection can become much more difficult to treat, as the bacteria become antibiotic-resistant, meaning the medicines no longer work.
A hospital stay may be needed to prevent spreading the disease to others, until a person is no longer contagious. This will depend upon the policies of the country, in which the person is recovering and the strain of tuberculosis contracted.
Q: Are miliary TB and disseminated TB the same thing?
A: They are used by some interchangeably. However, they refer to slightly different things. The term miliary TB originally referred to the appearance of the involved lung: on a chest x-ray, the small, firm white nodules on the surface of the lung resembled millet seeds. It now means disseminated TB that is spread through the bloodstream, i.e. when a tuberculosis lesion erodes into a blood vessel, disseminating millions of tubercle bacilli into the bloodstream and throughout the body. Some use miliary incorrectly, to describe any disseminated TB, whether or not it has the classic millet-like appearance associated with spread through the bloodstream.
Q: What is the difference between pulmonary TB and disseminated TB?
A: Tuberculosis is usually contained in the lungs, when it is known as pulmonary tuberculosis. Tuberculosis that has spread to other organs is known as disseminated tuberculosis.
Q: Can disseminated tuberculosis be fatal?
A: With treatment, most people will recover from disseminated tuberculosis. However, without treatment, such as may be the case for people living in developing countries, fatality may be likely.
Other names used for disseminated tuberculosis
- Disseminated TB
- Extrapulmonary tuberculosis
- Widespread tuberculosis
- Tuberculosis outside the lungs
- Miliary tuberculosis or tuberculosis cutis miliaris disseminata (disseminated tuberculosis that is spread by the blood)
- Tuberculosis acuta generalisata (a rare form of cutaneous tuberculosis)
"Clinical manifestations, diagnosis, and treatment of miliary tuberculosis.” UpToDate. 2 October 2018. Date Accessed: 9 January 2019. ↩ ↩
The lymph system is a network that makes and moves lymph – a fluid that helps the body fight infection – from tissues to the bloodstream. ↩