Every year 80 million tourists travelling to tropical and subtropical areas contract traveler's diarrhea.
About 40% to 80% of cases are caused by bacteria, yet clinical diagnostic tests are available to identify only a few of the strains that cause traveler's diarrhea.
Dr Jenni Antikainen and colleagues from Finland reported developed a quantitative PCR assay to identify all major pathogens in stool samples.
The researchers developed a low-cost, high-throughput, multiplex quantitative PCR assay for simultaneous detection of 9 bacterial pathogens in stool samples, including Salmonella, Yersinia, Campylobacter, and Vibrio cholerae, as well as Shigella or enteroinvasive Escherichia coli, enterohemorrhagic E coli, enterotoxigenic E coli, enteroaggregative E coli, and enteropathogenic E coli.
The doctors noted that the assay was validated using positive and negative control strains as well as preselected positive and negative stool samples.
In addition, stool samples were collected from 96 returning travelers with traveler's diarrhea.
The findings were compared with those from routine diagnostic tests.
The assay detected the bacterial strains with 100% sensitivity and specificity, compared with results from the reference tests.
|Multiple pathogens were found in 37% of all samples|
|Clinical Gastroenterology and Hepatology|
The research team assessed that of all stool samples collected from travelers with traveler's diarrhea, enteropathogenic E coli was found in 47%, enteroaggregative E coli in 46%, enterotoxigenic E coli in 22%, enterohemorrhagic E coli in 7%, Campylobacter in 6%, Shigella or Escherichia coli in 2%, and Salmonella in 2%.
Multiple pathogens were found in 37% of all samples.
Dr Jenni's team commented, "We developed a low-cost, high throughput quantitative PCR assay for use in routine diagnostic analysis and research."
"It detects the pathogenic bacteria most commonly associated with traveler's diarrhea in stool samples with 100% sensitivity and specificity, compared to reference methods."
"The assay requires 4 hours, whereas current detection methods require 1–7 days."
"At least 1 traveler's diarrhea pathogen was identified in stool samples from 76% of returning travelers, whereas conventional methods found a pathogen in only 17%."
"The most commonly detected bacteria were enteropathogenic E coli, enteroaggregative E coli, and enterotoxigenic E coli."