Tuberculosis: A Global Health Challenge
As we observe the World Tuberculosis Day on 24 March 2024, it is also a reminder to raise awareness and support for the fight against Tuberculosis (TB), which still affects millions of people every year around the world.
Dr Hanssa Dwarka Summah, Chest Specialist, answers some key questions for us about TB and its impact on public health. She also shares some of the latest advancements and innovations in TB diagnosis, treatment, and prevention, and explains how we can all play a role in ending TB.
1. What is Tuberculosis (TB) and how does it differ from other respiratory infections?
Tuberculosis is an infectious disease caused by the bacteria called Mycobacterium tuberculosis.
Unlike many other contagious diseases which also spread through inhalation of tiny droplets from the coughs or sneezes of an infected person, TB can remain dormant in the human body for years before causing symptoms.
TB affects primarily the lungs, causing pulmonary tuberculosis.
In about 25% of cases, TB can also affect other organs such as the lining of the lungs (TB pleuritis), the heart (TB pericarditis), the brain (TB meningitis), the bones, joints, lymph nodes, liver, spleen, intestines, kidney and bladder. This is called extrapulmonary tuberculosis.
When the bacteria spread widely through the bloodstream and infect the lungs and other organs, it results in a severe form of the disease known as miliary tuberculosis.
2. How is TB diagnosed, and what are the common diagnostic tests used?
Symptoms including considerable weight loss, intermittent fever, night sweats, fatigue, poor appetite, and haemoptysis (coughing up blood) should raise the suspicion of TB.
Pulmonary TB is diagnosed with Chest X-rays and sputum laboratory tests, including staining and rapid molecular tests.
For extrapulmonary tuberculosis, a biopsy of the affected site may be necessary.
Additionally, the Mantoux skin test or the IGRA (interferon-gamma release assays) blood test may aid in the diagnosis of TB.
It should be noted that a positive result from a skin or blood test only indicates increased immune response to the bacteria, rather than confirming an active disease.
A confirmed diagnosis of tuberculosis is made by growing the Mycobacterium tuberculosis bacteria from samples of sputum or tissue biopsy.
3. What are the recommended treatments for TB, and how long do they normally last?
Treatment for tuberculosis often starts before a confirmed diagnosis by bacterial culture since it takes weeks to grow the bacteria in a lab. The World Health Organization (WHO) advises a six-month daily regimen for patients diagnosed with TB.
Treatment may need adjustment and extension based on the patient’s other health conditions, baseline blood test results, and affected organ.
The common antibiotics used include isoniazid, rifampicin, pyrazinamide and ethambutol. The treatment consists of an intensive phase of 2 months with 4 antibiotics followed by a 4-month continuation phase with two antibiotics.
Improper use or early discontinuation of TB medications can lead to the development of drug resistance.
4. How effective are TB vaccines such as the Bacillus Calmette-Guérin (BCG) vaccine, and who should receive them? (To talk about the Bacillus Calmette-Guérin (BCG) vaccine)
WHO recommends the BCG vaccine to be done shortly after birth.
In Mauritius, it is administered at the age of one month to all newborns to prevent severe forms of the disease such as TB meningitis and miliary TB.
The effects of the BCG vaccine diminish over time.
5. Are there any recent advancements in TB diagnosis, treatment, or prevention?
Recent advancements have expanded the availability of molecular tests for TB diagnosis, offering faster and more accurate detection.
The treatment for drug-resistant TB has also undergone a significant shift with new medications, leading to a shorter treatment period.
Additionally, several drugs and vaccines are being tested for TB treatment and prevention.
6. Can you list some lifestyle factors that affect the transmission and prevention of TB?
Individuals with diabetes, malnutrition, or those who consume alcohol, use illicit drugs, and smoke regularly are at higher risk of developing TB.
Similarly, residing in overcrowded areas with poor ventilation also increases the chances of being infected with TB.
Moreover, people living with HIV are 18 times more prone to developing TB compared to those who do not have HIV.
7. What is your message to the public about TB and its health consequences?
Tuberculosis is a contagious and preventable disease.
If you are prescribed any tuberculosis preventive therapy (TPT) by your doctor, make sure that you follow through it. It has been demonstrated that TPT can reduce the risk of developing TB disease by 60-90%.
TB diagnostic tests are readily available in Mauritius. If you experience symptoms like weight loss, fatigue, night sweats and haemoptysis or if you have been in close contact with a person who has TB, consult your doctor for a screening.
Dr Hanssa Dwarka Summah
Chest Specialist
MBBS
MD Respiratory Medicine
MSc Respiratory Medicine
Fellowship in Interventional Pulmonology
DU Infection VIH, Hépatites Virales et Addictologies
