Validation of the saliva-based H-pylori test, HeliSAL (TM), and its use inprevalence surveys

The saliva-based H. pylori test, HeliSAL (TM), is insufficiently accurate f or use in the clinical setting. However, its ease of use and non-invasivene ss make it attractive for population-based studies of the epidemiology of H . pylori. We validated HeliSAL (TM), 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 assessmen t, which were compared to CLOtest (Delta West Pty Ltd, Western Australia) a s a gold standard measure. Nineteen percent were truly H. pylori positive, 41% were positive according to HeliSAL (TM). Test sensitivity was 74% and s pecificity was 67 %. While HeliSAL (TM) is not well suited for the clinical diagnosis of H. pylori infection, it may be useful for large-scale prevale nce surveys because, provided it is validated locally, mathematical adjustm ent can be made for misclassification. Being inexpensive, non-invasive, and easily stored and handled, HeliSAL (TM) may be a valuable tool for studies of the epidemiology of H. pylori.