MIT researchers have revealed that undiagnosed gastrointestinal infections might increase the severity of and delay recovery from acute diarrhoea.
They have found that the underlying, low-level undiagnosed infection may greatly add to the severity of a significant number of fatal diarrhoea cases.
"It seemed likely that persistent enteric infection with bacterial agents would also elicit immune responses that could have similar effects. However, this had not been previously studied," said David Schauer, MIT Professor of Biological Engineering and Comparative Medicine.
"We wanted to provide proof of principle, and begin to define the mechanism for such an interaction," he added.
During the study, the team used laboratory mice infected first with a strain of bacteria that causes a chronic condition but produces no symptoms, and then with a second infectious agent that causes acute diarrhoea.
They found that even though the underlying chronic infection did not cause disease on its own, it did make the acute infection much worse than in a control group that was only exposed to the second agent.
About 50 percent of the world population carries a chronic infection with Helicobacter pylori, which causes stomach-lining inflammation but usually no clinical symptoms.
In the case of diarrhoea this may play a significant role.
"It may be that an individual's infection status with these or other agents is important in determining outcome of infection, immune-mediated disease or even immunization," said Schauer.
The research has been published in the journal Infection and Immunity.