Background

Although cases of TB have continued to decline over the last 10 years, London still has the highest incidence in England and the east London borough of Newham has the highest rate of TB in the country (42.8 per 100,000 on average from 2018-2020). Miliary TB makes up a minority of cases (3.9% in 2020) but has significant mortality. 

Aim

To describe the demographics, risk factors, investigations and outcomes of miliary TB in east London

Methods

In this retrospective observational study we used the London TB register to identify all notified cases of miliary TB (?12 years old) in inner East London (under Barts Health NHS Trust) from 2014-2022. We performed electronic health record lookup to supplement registry data. 

Results

Of 85 cases of miliary TB (35% women, median age 42, 81% UK-born), the commonest risk factor was immunosuppression (16%) but 62% had none. 74 had brain imaging with 10/36 CTs and 30/56 MRIs suggesting intracranial TB. 53% had any positive culture (18/50 sputum, 24/56 bronchoalveolar lavage). 62 patients were admitted to hospital and the mortality during treatment was 12.5%. There was no significant difference in mortality between those with and without CNS TB (10.7% vs 13.5%, p = 1); or between culture positive and negative patients (11.9% vs 13.2%, p = 1). 78% with positive sputum cultures had a predominantely miliary pattern on initial imaging. Patients with any positive culture were more likely to have a clear chest x-ray at the end of treatment (44% vs 29%, p = 0.033173).

Conclusion

In the socioeconomically deprived areas of east London where TB is most common, the mortality from miliary TB mortality is high with relatively low rates of culture positivity.