How much do you really know about tuberculosis?
The World Health Organisation designated Tuesday the 24th of February 2020 as World Tuberculosis Day.
Today, TB remains the world’s deadliest infectious killer, claiming many lives on a daily basis.
As global citizens, we can do our part by educating ourselves about the condition, in order to stop the discrimination and stigmatization encountered by many TB patients, and also as healthcare professionals, in the management of TB.
Here’s a quiz for you. Let’s meet our patient now, shall we?
Samuel is a 32 year old male who presented with subjective fever, malaise, and cough. He also reported 3 episodes of hemoptysis, and admits to night sweats. He suspects he has had significant weight loss as his jeans are now lose-fitting. He denies any sick contacts, but admits recent travel to India. What species causes TB infection?
Mycobacterium tuberculosis is the main pathogen causing 95% of cases and is mostly spread by droplet infection. Mycobacterium Bovis is another species that can cause gastrointestinal tuberculosis.
After taking a detailed history, you determine this is a case of reactivation tuberculosis. You remember studying that latent TB infection (LTBI) may be reactivated by certain factors. Which one of the following from Samuel’s history is most likely to have activated his infection?
Although alcohol abuse can cause reactivation of LTBI, HIV infection has a high risk of reactivating the infection in patients. Systemic corticosteroids can also cause reactivation. Those with latent TB infection are not infectious.
During your physical examination, you assess for extra-pulmonary TB. Which one of these sites is not likely to be affected in extra-pulmonary TB?
Extra-pulmonary TB includes infection of the vertebral column (tuberculous spondylitis – Pott disease), military tuberculosis which can involve the liver, and pericarditis with pericardial effusions.
You decide to take Samuel for a chest x-ray, you know, to see his lungs right? You receive the images and crosscheck them with your colleague. What findings are you both most likely looking at?
You return to Samuel to tell him you have reviewed his imaging studies with your colleague. He asks you what happens next. What is your next step in appropriately managing him?
The imaging studies already point to the suspected diagnosis, so a high-resolution scan isn’t appropriate. A biopsy is an invasive procedure and is not routinely done to confirm TB. Before medical management is started, sputum samples need to be collected to allow for a definitive diagnosis.
The sputum samples are sent for investigation. However, since culturing will take time to yield results, you check on the PCR and microscopy results. Positive. While devising your next management step, you ask yourself what stain is used in the microscopy test for M. tuberculosis. Do you know the answer?
Ziehl-Neelsen stain is appropriate for the species Mycobacterium tuberculosis. Congo red staining is used in amyloidosis and for amyloid deposits. PAS reaction is most appropriate for glycogen storage diseases and certain fungi (aspergillosis). Giemsa staining is suitable for certain parasites
After discussing the clinical case with the specialised clinician, you are asked to initiate the medical management to the patient. What is the medical management for Samuel?
Initiation of RIPE (Rifampin + Isoniazid + Pyrazinamide + Ethambutol) for 2 months and continuation with Isoniazid + Rifampin for 4 months is recommended for treating active TB infection.
As you leave the negative pressure room, Samuel calls you back and says he forgot to tell you that he is currently living with his adult brother. What should be your next plan of action?
IGRAs (Interferon-gamma release assay) needs to be performed to exclude a latent TB infection in at-risk populations. Imaging is then appropriate to screen for active disease.
Finally, what is a possible social barrier to the management of certain medical conditions like TB in patients?
According to WHO, stigma and discrimination are noted to be a few of the most common barriers to fighting the TB epidemic. It is not ok to discriminate or stigmatize those suffering from TB, and it is important for us as current/aspiring healthcare workers to keep that in practice. Stigma is detrimental in that it hinders those to seek appropriate care, contact tracing, adherence, and appropriate care. It also simply denies people with TB respect from others.
Ola is a medical student at The Royal College of Surgeons Ireland (RCSI).