Tuberculosis is an infectious disease that is fatal enough to cause death if left untreated for long periods of time. The most common type of tuberculosis is pulmonary tuberculosis, where the organism infects the lung and causes an array of signs and symptoms such as fever, prolonged dry cough, loss of weight and loss of appetite.
Apart from that, there is another type which is extrapulmonary tuberculosis where it infects the gastrointestinal system, the nervous system, the skin or the joints. The organism responsible for the deadly infectious disease is Mycobacterium tuberculosis which is the typical form. This organism is difficult to be cultured in the laboratory and requires a special medium to grow them.
Treatment of tuberculosis involves consuming anti-tuberculosis medication after taking advice from doctor for at least 6 month duration with frequent routine follow ups to monitor your disease progression and healing.
5 ways to detect tuberculosis
- Tuberculin skin test or the Mantoux test
This test simply means injecting an inactive form of the tuberculosis organism beneath the skin. It is called purified protein derivatives. After injecting them intradermally beneath your skin, the injected area will be marked with a circle to note the changes after 48 to 72 hours.
You are advised to not expose the area to water during your bath or washing hands. After 48 to 72 hours, the size of the swelling will be measured and evaluated according to risk factors. If you are from high risk groups such as immunocompromised patients and had a close TB contact, a measurement of 5mm is considered as positive screening.
However, further investigations have to be taken to confirm your diagnosis before starting your treatment as this test is only used as a screening method.
- Sputum Acid fast bacilli (AFB)
The mycobacterium organism cannot be stained by using the common gram staining method, as its structure contains complex mycolic acid as an outer shield. Thus, it has to be stained using the acid fast bacilli. Your sputum will be commonly collected in the morning in 3 specimen bottles.
The sputum is then stained with few chemicals such as hydrochloric acid, alcohol and carbolfuchsin. A positive smear will indicate a possible tuberculosis infection.
- Sputum culture and sensitivity
Mycobacterium tuberculosis are commonly cultured by using the Lowenstein Jensen medium which takes about 4 to 8 weeks duration. Newer mediums such as OGAWA and Middlebrook medium take a shorter period of time to culture these organisms.
Due to this duration constraint, doctors sometimes do not wait for the results of culture and sensitivity to start anti tuberculosis treatment. They will usually rely on other faster and efficient investigations like acid fast bacilli staining and chest x ray.
- Chest x ray
An anteroposterior view of your chest radiograph will be usually taken to view for any changes. Commonly for primary tuberculosis, the middle and lower lobe of your lung will be affected with a consolidation pattern, while for secondary tuberculosis, the upper lobe involvement with cavitation can be seen.
At times, there will be no changes seen in the xray but tuberculin skin test can be positive. This condition is called a latent tuberculosis infection and is treated differently.
The tuberculosis infection is a deadly infectious disease that killed many lives especially before the innovation of the BCG vaccine. Some common symptoms of tuberculosis are low grade fever, prolonged dry cough, loss of weight, loss of appetite and night sweats.
Your doctor will usually take a thorough history and do some assessments before proceeding to conduct some diagnostic and supportive investigations as stated above before starting the anti- tuberculosis treatment.