Use of a multiplex DNA extraction PCR in the identification of pathogens in travelers' diarrhea.

Abstract

Diarrhea is one of the most common ailments afflicting travelers with attack rates of 30-40% for medium to high-risk destinations. As travelers' diarrhea (TD) is syndromic and caused by a wide range of pathogens, including bacteria, parasites and viruses, multiplex deoxyribonucleic acid (DNA) extraction polymerase chain reaction (PCR) technology can be useful for determining the etiology of TD pathogens. The goal of this retrospective study was to produce clinically relevant and useful data on gastrointestinal illness related to travel identified by culture-independent methods of diagnosis-use of the multiplex DNA extraction PCR platform (BioFire FilmArray GI Panel) and to describe the use of this technology in detection of enteric pathogens. We reviewed our data in returned travelers from May 2014 to March 2017, looking at demographics, country of travel, number of pathogens found and pathogens by specific region. Stool analysis by DNA extraction PCR was obtained in 388 post-travel patients. Three hundred and twenty-seven of these had diarrhea or other enteric symptoms. Sixty-one travelers presented with enteric symptoms and were diagnosed with post infectious irritable bowel syndrome (PI-IBS) after stool analyses were negative. Of those with diarrhea or gastrointestinal (GI) symptoms and excluding those diagnosed with PI-IBS, 207 patients tested positive for at least 1 enteric pathogen (63.4%). Eighty of those patients were found to have multiple pathogens. Viral pathogens were identified in 38 patients, 18% of the total number of cases. The BioFire FilmArray GI Panel was associated with better detection of pathogens than historical controls while also allowing prompt and accurate diagnosis and potential treatment. A higher proportion of viral pathogens compared with historical assumptions was identified as well as mixed infections with multiple pathogens, a phenomenon largely unknown to clinicians before this technology became available.