Encounter for screening for respiratory tuberculosis.Care & specialists in Singapore

Tuberculosis spreads through airborne droplet nuclei generated when a person with active pulmonary TB coughs, sneezes, sings, or talks. These tiny particles stay suspended in the air for hours and are inhaled into the alveoli of nearby people. TB does not spread through food, sharing utensils, casual touch, or doorknobs. Risk is highest among household and close indoor contacts during the first 2-3 weeks before treatment is effective.

Latent TB infection means the bacteria are present in the body but contained by the immune system. There are no symptoms, chest X-ray is normal, and the person is not contagious. Active TB disease is symptomatic, shows abnormalities on imaging or microbiology, and is contagious if it involves the lungs. Roughly 5-10% of people with latent infection progress to active disease over their lifetime.

Early signs include a cough lasting more than 2-3 weeks, unintentional weight loss, low-grade evening fevers, drenching night sweats, and progressive fatigue. Chest pain, breathlessness, and blood in the sputum appear later as cavitary disease develops. Painless lymph node swelling can be the first sign of extrapulmonary TB.

Drug-susceptible pulmonary TB is cured with 6 months of standard therapy (2 months of four drugs followed by 4 months of two drugs). A WHO-endorsed 4-month rifapentine-moxifloxacin regimen is now an alternative for adolescents and adults. Drug-resistant TB previously needed 18-24 months but is now treated with all-oral 6-month BPaL or BPaLM regimens.

Yes. Drug-susceptible TB is cured in 85-90% of patients who complete the standard 6-month regimen. Multidrug-resistant and extensively drug-resistant TB are curable with newer regimens such as BPaL or BPaLM, which achieve favourable outcomes in roughly 80-89% of patients in 6 months.

The 2022 WHO guideline recommends Xpert MTB/RIF or Xpert MTB/RIF Ultra as the initial test for everyone with presumptive pulmonary TB, with sensitivity around 88% in smear-positive disease. Sputum smear microscopy and mycobacterial culture confirm and monitor treatment. Chest X-ray supports the diagnosis. Latent TB is diagnosed by tuberculin skin test or interferon-gamma release assay.

Multidrug-resistant TB (MDR-TB) is caused by strains resistant to at least the two most powerful first-line drugs, isoniazid and rifampicin. The WHO estimates around 410,000 new cases globally in 2022. It is harder to cure than drug-susceptible TB and requires longer regimens with newer drugs such as bedaquiline, pretomanid, and linezolid.

Yes. Children under five are at the highest risk of progressing rapidly from infection to severe disease such as miliary TB and tuberculous meningitis. Pediatric cases account for around 11% of incident TB but a disproportionate 15% of TB deaths. Contact investigation around every adult case includes screening all child contacts.

The BCG vaccine is highly effective against severe paediatric forms of TB such as miliary disease and tuberculous meningitis, with 70-80% efficacy in newborns. Its protection against adult pulmonary TB is variable and generally lower. BCG is given routinely at birth in most TB-endemic countries but is not used in low-incidence countries such as the US.

Yes. Successful treatment cures the current episode but does not provide complete immunity. Relapse from the original strain typically occurs within 2 years of cure, while reinfection with a new strain can occur at any time, especially in high-transmission settings. Symptoms similar to the first episode should prompt rapid re-testing.

Pneumonia is acute over days, with high fever, focal lobar consolidation, and rapid improvement on standard antibiotics. Tuberculosis is subacute over weeks, classically with upper-lobe cavitation, weight loss, and night sweats. A pneumonia that fails to clear after appropriate antibiotics in an at-risk patient should be tested for TB.

Yes. The WHO estimates 10.6 million new cases and 1.3 million deaths in 2022, making TB the second-largest infectious killer worldwide after COVID-19. Eight countries (India, Indonesia, China, the Philippines, Pakistan, Nigeria, Bangladesh, and DR Congo) account for roughly two-thirds of new cases.

Yes. Around 20% of cases are extrapulmonary, including lymph node TB (most common), pleural TB, TB of the spine and bones (Pott disease), genitourinary TB, abdominal TB, and tuberculous meningitis. Extrapulmonary TB is more frequent in young children and people with HIV.

Adults born in or with extended residence in high-incidence countries are typically offered latent TB screening with an interferon-gamma release assay. The CDC and WHO recommend offering preventive therapy to anyone with a positive test, especially before starting biologic therapy, dialysis, or transplant medications.

Most patients with drug-susceptible pulmonary TB become non-contagious after 2-3 weeks of effective therapy, marked by clinical improvement and smear conversion. Drug-resistant TB takes longer. Until then, patients should stay home, cover coughs, ventilate living spaces, and wear a mask in shared indoor settings.

Yes. Isoniazid, rifampicin, ethambutol, and pyrazinamide are considered safe in pregnancy and are used in standard therapy for drug-susceptible TB. Pyridoxine supplementation is mandatory. Streptomycin is avoided because of fetal ototoxicity, and second-line agents in MDR-TB pregnancy are selected with specialist input.

Standard first-line drug-susceptible TB regimens are provided free of charge in most national TB programs and through the WHO Stop TB Partnership Global Drug Facility. Out-of-pocket costs (visits, imaging, lost wages) still cause catastrophic expenditure in many households. MDR-TB regimens are more expensive but increasingly subsidised globally.

Directly observed therapy (DOT) means a healthcare worker watches the patient swallow each dose, in person or by video. It is the most reliable way to support adherence and the WHO standard of care for active TB. Video DOT and digital pill monitors are increasingly used alongside in-person observation.

Yes. Cavitary or severe TB can leave behind scarring, bronchiectasis, pulmonary fibrosis, and aspergillomas in 20-50% of survivors. These can cause chronic cough, breathlessness, and recurrent infections. Pulmonary rehabilitation and inhaler therapy may help; haemoptysis from residual cavities sometimes needs bronchial artery embolisation.

Common side effects include nausea, rash, joint pains, and orange discolouration of urine and tears from rifampicin. Serious adverse events include hepatotoxicity from isoniazid, rifampicin, and pyrazinamide (1-3% of adults), optic neuritis from ethambutol, peripheral neuropathy from isoniazid (prevented by pyridoxine), and myelosuppression or neuropathy from linezolid.

Tuberculous meningitis is TB involving the meninges and brain, presenting subacutely over 2-4 weeks with headache, fever, vomiting, confusion, and cranial nerve palsies. It is diagnosed by lumbar puncture with Xpert MTB/RIF Ultra, CSF biochemistry, and culture. Treatment uses standard anti-TB drugs for 9-12 months plus adjunctive corticosteroids, which reduce mortality.

Yes. Household and close contacts of an infectious TB case should be evaluated promptly for symptoms, undergo chest X-ray, and have an IGRA or tuberculin skin test for latent infection. Eligible contacts are offered preventive therapy. Children under five and people with HIV are prioritised because of their higher risk of rapid progression.