• Infection caused by bacteria of the Mycobacterium tuberculosis complex, predominantly Mycobacterium tuberculosis and more rarely Mycobacterium bovis. Active pulmonary TB is the most common presentation. Active extrapulmonary TB presents with symptoms specific to the site involved, such as the CNS (typically the meninges), peripheral lymph nodes, bones and joints, pericardium, and genitourinary system. Extrapulmonary TB is a more common presentation in children, people born in countries with a high prevalence of TB, and people who are immunocompromised, for example with HIV.  Latent TB occurs when the Mycobacterium bacteria remain dormant, and is asymptomatic and not infectious. However, in about 10% of people, latent TB can be reactivated during their lifetime and becomes active (symptomatic) disease (for example, if the person becomes immunocompromised or takes corticosteroid drug treatment). MDR-TB refers to a strain of TB that is resistant to two first-line drugs and often requires prolonged specialist treatment

• Migrants comprise approximately 12% of the UK population, the majority of whom are young people with similar health problems to the UK born population.  However 72% of TB cases occurred in people who were born abroad and general practitioners can play an important role in the early identification of this infection.

• Investigations: Suspected active pulmonary TB: CXR (cavity, pleural effusion, lymphadenopathy, or parenchymal infiltrates, mainly in the upper lobes) and 3 sputum samples (ideally, one sample taken in the early morning) for microscopy to look for AFB and for culture.Suspected extrapulmonary TB: CXR and consider the following additional investigations depending on the likely site of disease: Joint or spinal plain X-ray, abdominal or renal tract ultrasound scan, or early morning urine samples for dipstick testing and Mycobacteria culture

• Management of suspected active TB: If hospital admission is not needed, arrange urgent (ideally within 2 weeks) referral to a specialist TB service for confirmation of the diagnosis and ongoing management

• Specialist management of confirmed TB: notifiable disease (within 3 days). Usually 6M of isoniazid and rifampicin, supplemented in the first 2 months with pyrazinamide and ethambutol ('directly observed therapy' (DOT)). Contact tracing

• Patients with TB born outside the UK are more likely to have drug-resistant disease. Around half of non-UK born people presenting with TB, who have first-line drug resistance, are born in South Asia.

Resources

• Public Health England. Tuberculosis annual report. 2021, Tuberculosis (CKS), Tuberculosis (NHS Choices), Mycobacterial infections (PCDS), Tuberculosis (CDC), Tuberculosis (gov.uk), Tuberculosis (WHO)