Background Helicobacter pylori is a gram negative organism commonly found in the stomach. The majority of patients infected don’t experience any symptoms or complications however it can be associated with PUD, Gastric MALT Lymphoma, Gastric Cancer and chronic gastritis. We usually diagnose H. Pylori with the use of CLO testing at endoscopy.

Aim We wanted to assess the sensitivity of these kits after a number of “negative” CLO tests had H. pylori confirmed at histology. This is important given the carcinogenic properties of H. Pylori.

Method This was a retrospective analysis of every CLO test that was performed between 01/08/16 and 31/10/16. For each patient that had a CLO test we checked the lab system for histology samples to check for any disparity. We also recorded the diagnosis at oesophagogastroduodenoscopy (OGD) and whether or not the patient was taking PPI medications.

Results 179 OGDs with CLO tests were performed in the specified time period. 11/179 were CLO positive (6.1%). 25/179 samples were sent for histology. 5/25 were CLO negative, histology positive. 2 of these patients were on a PPI. 19/25 were CLO negative, histology negative. 1 patient was CLO positive, histology positive.

Conclusions In a 3 month period, 5 cases of H. pylori would have been missed if histology wasn’t sent. The diagnostic yield for H pylori at histology was 24% compared to 6.1% with CLO testing. Given the carcinogenic properties of H. pylori we are now recommending that samples should be sent to histology in addition to CLO testing, if H. pylori is suspected.