Overview

Patients with latent tuberculosis are asymptomatic and non-infectious. They are typically diagnosed by having a positive tuberculin skin test or Interferon-Gamma Release Assay (IGRA) combined with a normal chest x-ray, helping to exclude active tuberculosis.

NICE now give two choices for treating latent tuberculosis:

• 3 months of isoniazid (with pyridoxine) and rifampicin, or
• 6 months of isoniazid (with pyridoxine)

Why two choices? NICE (2016) state the following:

Base the choice of regimen on the person's clinical circumstances. Offer: • 3 months of isoniazid (with pyridoxine) and rifampicin to people younger than 35 years if hepatotoxicity is a concern after an assessment of both liver function (including transaminase levels) and risk factors • 6 months of isoniazid (with pyridoxine) if interactions with rifamycins are a concern, for example, in people with HIV or who have had a transplant.

People with latent tuberculosis cannot pass the disease on to others, so there is no restriction in terms of employment etc. This advice would obviously change if the patient developed active tuberculosis at any point.

Risk factors for developing active tuberculosis include:

• silicosis
• chronic renal failure
• HIV positive
• solid organ transplantation with immunosuppression
• intravenous drug use
• haematological malignancy
• anti-TNF treatment
• previous gastrectomy