Validation of the saliva-based H. pylori test, heliSAL, and its use in prevalence surveys

The saliva-based H. pylori test, HeliSAL, is insufficiently accurate for use in the clinical setting. However, its ease of use and non-invasiveness make it attractive for population-based studies of the epidemiology of H. pylori. We validated HeliSAL, and comment here on its usefulness in prevalence surveys. One hundred and ninety-six patients receiving endoscopy at a clinic in New Zealand provided saliva samples for H. pylori assessment, which were compared to CLOtest (Delta West Pty Ltd, Western Australia) as a gold standard measure. Nineteen percent were truly H. pylori positive, 41% were positive according to HeliSAL. Test sensitivity was 74% and specificity was 67%. While HeliSAL is not well suited for the clinical diagnosis of H. pylori infection, it may be useful for large-scale prevalence surveys because, provided it is validated locally, mathematical adjustment can be made for misclassification. Being inexpensive, non-invasive, and easily stored and handled, HeliSAL may be a valuable tool for studies of the epidemiology of H. pylori.