In comparison to the UK’s low average incidence of Tuberculosis (TB) at 9.9 per 1 00 000 population (2), the London Borough of Newham stands out as having the highest UK 3 year average annual incidence at 69.5 per 1 00 000 population (1), which is on par with some endemic countries in Asia and Africa (2). This is due to its predominance of non-UK born residents and socio-economic deprivation. It can often be difficult to differentiate between Crohn’s disease (CD) and TB ileitis and missed cases of intestinal TB treated with immunosuppression could potentially have devastating consequences. We proposed a service change in Newham University Hospital routinely testing for TB in any case of ileitis found at colonoscopy, and evaluate its impact on TB detection.Method
Before the study period, all endoscopists performing colonoscopies at Newham University Hospital were instructed to routinely send a TI biopsy sample for Ziel-Nielson staining for Acid-fast Bacilli (AFB) and in saline for TB culture, if they found macroscopic inflammatory changes suggestive of terminal ileitis (such as ulceration or erythema). Data was collected from patient records for all ileocolonoscopies performed between 3rd October 2016 and 5th May 2017.Results
The TI was visualised in 46.2% of the 649 colonoscopies recorded. 25 cases of macroscopic terminal ileitis were reported (8.3% of total ileocolonoscopies). 40% of the patients were of South Asian ethnicity, 40% British Caucasian and 12% Eastern European. The macroscopic descriptions of ileitis included erythema and oedema only (28%; n=7), the additional presence of <5 aphthous ulcers (60%; n=15) and >5 aphthous ulcers or larger ulcers (12%; n=3). All TI samples sent for AFB and TB culture were negative (n=18). 15 patients were subsequently diagnosed with histologically confirmed inflammatory bowel disease.Conclusions
We did not detect a positive TB culture in the study period. However, with those patients from TB endemic countries with negative TI TB cultures, we have noted improved confidence amongst the Gastroenterologists in diagnosing CD and initiating immunosuppression. Uncertainty often prompts rescoping of patients just to exclude TB with its obvious cost implications. In contrast a TB culture costs only £30 in our Trust. This study is ongoing and with further data we will be able to evaluate cost effectiveness.