MALAYSIANS carry the scar of the BCG (Bacille Calmette-Guerin) vaccine.
Most of us received the shot as babies and during primary school to gain protection against tuberculosis (TB).
But what many do not know is that its effectiveness wanes over the years, and by the time we are adults, many of us no longer have that immunity.
While Malaysia is not on the World Health Organisation's (WHO) top 30 high-burden countries for TB, it is still considered a country with a high incidence rate, estimated at 92 per 100,000 people.
One of the challenges in detecting TB is that the disease doesn't present with symptoms immediately, says International Medical University head of division of medicine, school of medicine, Professor Dr James Koh.
"You could have been exposed long ago, and the bacteria will stay latent or dormant in the body and hibernate. Symptoms can come up months or even years later."
The slow and subtle onset of symptoms is also unlikely to set off alarm bells until the disease has advanced to a stage where you find yourself coughing up blood.
The good news is that while TB is contagious, it is not as contagious as Covid-19.
Similar to all respiratory diseases, it is spread through water droplets that come from coughing or spitting. However, unlike the coronavirus, the bacteria that causes TB is heavy so these need to be significant water droplets.
"You have to be in quite close contact and in a situation where there's prolonged exposure — generally, more than eight hours a day," explains Dr Koh.
Some examples of close contacts would be immediate carers, office mates or those living in the same house.
Pre-pandemic, in 2018, Malaysia recorded 25,837 TB cases. During the pandemic, in 2020 and 2021, cases decreased to 23,644 and 21,727 respectively.
Dr Koh says this was due to people wearing masks, maintaining physical distancing, and adhering to movement control orders — all of which helped dampen the spread of TB.
With the relaxation of these standard operating procedures, the incidence of TB has risen back to pre-pandemic levels.
Last year, 25,391 cases were recorded, although WHO's incidence rate estimates the actual number to be around 30,000.
MOVING FORWARD
There is no "booster shot" to raise immunity levels against TB.
The best way to keep it at bay is to ensure a healthy lifestyle.
Dr Koh says generally, a person who is healthy with a good immune system should be able to fight off the disease on their own.
It also helps to be aware of TB symptoms, as early treatment is crucial.
If left for too long, even after recovery, TB can leave scarring on the lungs that will forever affect a person's lung capacity.
BE AWARE
TB can attack different parts of the body, with the lungs — referred to as pulmonary tuberculosis (PTB) — being the most common.
The four cardinal symptoms of PTB are:
* Chronic cough
*Profuse night sweats
*Weight loss
*Recurrent rise in body temperature in the evenings