H. pylori can spread through vomit

MedWire News: Helicobacter pylori infections can spread through vomit, research conducted in Bangladesh suggests.

The findings could help explain the increased risk for H. pylori transmission during episodes of Vibrio cholera and other gastrointestinal infections that cause vomiting.

Anders Janzon (University of Gothenburg, Sweden) and colleagues studied vomited matter and stool samples from 28 patients admitted to a Dhaka hospital in Bangladesh with acute diarrheal disease.

Real-time polymerase-chain reaction (PCR) revealed that 88% of the 26 vomit samples and 74% of the 23 stool samples tested were positive for H. pylori.

Stool antigen tests revealed that 67% of the 21 stool samples were also positive for the bacterium However, H. pylori could not be isolated by culture.

Quantitative culture and real-time PCR methods to detect V. cholera correlated strongly, which the researchers say validated use of real-time PCR in this setting. H. pylori virulence genes cagA, flaA, and urea were highly transcribed in vomited matter, biopsy specimens, and in vitro cultures, whereas hpaA and vacA were expressed at lower levels. H. pylori gene expression was not detected in diarrheal stools.

Reporting in the journal Helicobacter, the researchers say that the high numbers of transcriptionally active H. pylori shed in vomited matter indicates that new infections may be spread in this way.

“We conclude that there may be an increased risk for H. pylori transmission during episodes of V. cholera or other gastrointestinal infections that cause vomiting, especially if the diseases strike very close-living communities where it is difficult to isolate the patient from the rest of the family and surrounding community,” they add.

“We further suggest that vomitus rather than diarrheal stool is the most likely route of dissemination and transmission during these outbreaks, and that it may explain the transmission pattern in these communities, with new cases of H. pylori being contracted from both parents and from nonparental guardians.”P>