Primary care medicine

Coughing too much? It could be tuberculosis

Tuberculosis is a contagious disease caused by a bacteria called Mycobacterium Tuberculosis. It can affects any parts of the body but more commonly the lung. Mycobacterium tuberculosis spread from an infected person to another person through tiny droplets released into the air during coughing, sneezing or spitting. 

The number of tuberculosis infection continues to rise every year in Malaysia and globally. Adult patient with active infection to the lung ('pulmonary TB') typically presents with respiratory symptoms such as prolonged cough, coughing up blood (haemoptysis), chest pain, difficulty breathing and constitutional symptoms such as fever, night sweat, tiredness, weight loss, loss of appetite and enlarged lymph nodes. Tuberculosis can cause infection in the brain (TB meningitis) causing persistent headache, change in mental state and coma. Tuberculosis in children can cause prolonged fever, failure to thrive, persistent chest infection and weight loss. 

Risk factors for developing TB are:

  • Close contacts with TB patients
  • Immunocompromised state such as diabetes, HIV, COPD, kidney failure, malnutrition, having cancer or receiving cancer treatment, use of medications that can suppress immune system such as immunosuppressant and steroid
  • Smoker
  • Excessive alcohol consumption
  • Illicit drug use
  • Living in overcrowded housing area or institution like prison

TB screening can be done by performing Mantoux test. The positive cut-off of 10 mm in a person without BCG and 15 mm with previous BCG is highly suggestive of tuberculosis infection, however it needs to be correlated with patient's clinical features

Latent TB is defined as infection with Mycobacterium tuberculosis, where the bacteria may be alive but in the state of dormancy. Patient with latent TB usually do not develop any symptoms and no damage can be seen on chest xray. However, a Mantoux test will indicate that the person have TB infection likely after being exposed to an individual with unsuspected active TB. Studies have shown that the lifetime risk of developing TB reactivation among those with latent TB is about 5 - 10% which tends to occur within the first two years after exposure.

Diagnosis of TB is supported by chest xray and laboratory testing. Confirmation of TB is by detection of acid fast bacilli (AFB) on smears and cultures from clinical specimens such as sputum, spinal fluid or tissue sample.

Patient with active pulmonary TB will  required isolation in negative pressure room as it is an airborne disease. All close contacts need to be screen and treated. Medications use for TB treatment usually contained a fixed- dose combination tablets such as Akurit for standard duration of 6 months regimen. The dose will depends on patient's weight and usually given with prophylaxis Pyridoxine to prevent nerve injury. Duration may be longer in certain clinical cases such as TB meningitis, persistent positive AFB smear and presence of extensive lung damage from TB.

The prevalent of multi-drug resistant TB (MDR-TB) are increasing worldwide and in Malaysia especially compounded with HIV infection and increasing overcrowded housing. MDR-TB require a much more complex treatment regime that is not just costly but longer duration are needed and potentially more adverse side-effects from medications.

Standard regime of TB drugs can cause several side-effects such as skin rash, yellowing of skin and eye (jaundice) due to liver injury, nausea, loss of appetite, numbness and tingling over hands or feet, visual impairment, orange- colored urine and stomach pain. It is very important to keep a lookout of the side-effects when you are taking TB medication. Adherence to TB medication is critical to achive full clearance and cure from TB infection. Non- compliance to TB medication can leads to multi-drug resistant organism, multitude of organ complications and increase transmission to other people. 

TB is a serious public health issue and is the leading cause of death by an infectious disease, 10th leading cause of death worldwide and the leading killer of patient with HIV infection. Fortunately, its curable and preventable. If you suffered from prolonged cough and respiratory problems, talk to our doctor for more information.