TB: Silent threat making a comeback

Many people think tuberculosis (TB) is a disease from the past. In reality, it has never gone away and continues to spread quietly, writes Dr Noorsuzana Mohd Shariff, a senior lecturer at Universiti Sains Malaysia's Tun Abdullah Ahmad Badawi Cancer Centre.

It often begins with a small cough. Perhaps it is dismissed as a common cold, blamed on haze, or attributed to changing weather.

But when the cough lingers for weeks, the person carrying it may unknowingly be harbouring bacteria capable of infecting many others.

Tuberculosis (TB) is once again becoming a concern. In early February 2026 alone, Malaysia’s Health Ministry recorded 2,571 TB cases within a single month – an increase of nearly 10 per cent compared with the same period last year. Even more worrying, 10 active clusters have been detected across the country. These are not merely statistics. They are a warning.

An old disease that never truly disappeared

Many people think of TB as a disease from the past. In reality, it has never gone away and continues to spread quietly. TB is caused by the bacterium Mycobacterium tuberculosis, which spreads through the air. When someone with active TB coughs, sneezes or even speaks, tiny droplets containing the bacteria can linger in enclosed spaces and be inhaled by others.

The main symptoms include a persistent cough lasting more than two weeks, prolonged fever, night sweats, loss of appetite and unexplained weight loss.

What makes TB particularly dangerous is its silent nature. A person can carry the infection without obvious symptoms. When the body’s immune system weakens due to ageing, diabetes, cancer or other chronic conditions, the bacteria can become active and begin infecting others.

According to the World Health Organization, around 10 million TB cases are reported globally each year, with more than one million deaths. After the Covid-19 pandemic subsided, TB once again became the world’s leading infectious disease killer. Malaysia is not exempt from this global trend.

In fact, TB was once the leading cause of death in Malaysia during the 1940s and 1950s. Thousands of lives were lost each year before the National Tuberculosis Control Programme was introduced in 1961. The introduction of the BCG vaccine for infants and the implementation of the Directly Observed Treatment Strategy (DOTS) dramatically reduced mortality.

However, over the past decade, cases have begun to rise again. Rapid urbanisation, crowded living conditions, an ageing population, increasing numbers of diabetes patients, and disruptions to health screenings during the Covid-19 pandemic have all contributed to this trend. Although TB treatment is provided free of charge in Malaysia, the disease can still spread when detection comes too late.

When one case becomes a cluster

A TB cluster occurs when two or more cases are linked by location, timing or close contact. Often, it begins with a single index case that goes undetected.

Imagine a student in a dormitory who has been coughing for weeks but does not seek medical attention. In enclosed spaces with poor ventilation, the bacteria can easily spread to roommates or classmates. Without prompt treatment, one case can quickly develop into a cluster.

Even more concerning is that individuals with latent TB infection may appear perfectly healthy and active in their communities. By the time the disease becomes active, the chain of transmission may already be underway without anyone realising it.

Do not wait until it is too late

TB is both preventable and treatable, but it requires early action. If a cough persists for more than two weeks, do not ignore it. Visit a health clinic for screening. Early detection not only protects the individual but also helps safeguard family members and colleagues.

Good ventilation in homes and workplaces is also important. Opening windows and doors allows fresh air to circulate, while sunlight helps reduce bacteria in enclosed spaces. Practising cough etiquette is equally important. Cover your mouth and nose when coughing or sneezing. If symptoms appear, wearing a mask in public places can help reduce the risk of transmission.

For patients diagnosed with TB, completing the full course of treatment is crucial. Treatment typically lasts at least six months. Medication should not be stopped even when symptoms improve. Incomplete treatment can cause the bacteria to become drug-resistant, making the disease far more difficult to treat.

High-risk groups such as older adults and patients with diabetes, HIV or cancer must be particularly cautious, as weakened immunity increases vulnerability to infection.

Malaysia aims to achieve TB-free status by 2035 in line with the global End TB Strategy. However, this goal can only be achieved if society does not take early symptoms lightly. A persistent cough is not merely a minor inconvenience. It may be an early signal of a disease that spreads silently.

Tuberculosis is no longer a story from history books. It is happening around us today. We must not wait until a single cough becomes an outbreak. Act early, protect yourself and help safeguard the community.

Dr Noorsuzana Mohd Shariff is a senior lecturer at the Department of Community Health, Tun Abdullah Ahmad Badawi Cancer Centre, Universiti Sains Malaysia.

The views expressed here are the personal opinion of the writer and do not represent that of Twentytwo13.