A young odd-jobs man presented with cough for 3 months, associated with weight loss and fatigue at work. Finally seeking medical attention at a public hospital, he was found to have cavitation and infiltrates in the right upper lobe of the lung, with sputum microscopy showing high counts of acid-fast bacilli (AFB 4+). He was started on conventional anti-TB therapy and discharged. Subsequently, his cultures grew drug-susceptible Mycobacterium tuberculosis.

The young man postponed his hospital outpatient follow-up by a week, and on the following occasion, changed his appointment a few times owing to his work commitments. Unsure of his medication adherence, and perhaps tired of the administrative headaches, his doctor transferred him to the TB Control Unit (TBCU) for directly observed therapy (DOTS).

The old colonial-style house on Moulmein Road that houses the TB Control Unit in Singapore

At the TBCU, he was counselled again with regards to the importance of adherence to anti-TB medication, and started on DOTS at a polyclinic near his residence. However, over the next 3 weeks, he missed DOTS on 6 occasions, each time citing odd work schedules and fatigue from his long working hours.

Question: How should this matter be handled?

Non-adherence to TB treatment is both a clinical and public health concern. The patient risks both progression of TB infection, as well as the development of drug-resistant Mycobacterium tuberculosis that – in the worst case scenario – can be passed on to others. This is how the phenomenon of multidrug-resistant TB developed in many parts of the world.

In Singapore, the Infectious Diseases Act serves to prevent the transmission of infectious diseases. Therefore individuals who are persistently non-adherent to TB treatment can be compelled by the law to complete their treatment, failing which they will be deemed to have committed an offence, and are liable to be fined (not exceeding SGD10,000) or imprisoned (up to 6 months) or both.

However, most people who are initially non-adherent are not deliberate and wilful offenders. Some have experienced adverse effects (occasionally severe) to the anti-TB drugs, and are therefore leery of therapy that seems to make them worse than the disease. The majority fail to understand the implications of TB treatment, and/or find it difficult to fulfil occupational or social roles while undergoing daily treatment. There are multiple programs for counselling and social assistance at the TBCU, including provision of supermarket shopping vouchers to the destitute in exchange for achieving targets in TB treatment. So the heavy hand of the law has seldom been employed on patients who are non-adherent to TB therapy in Singapore.