# When One Stomach Bug Is Not Enough: A Five-Pathogen Gastroenteritis Case Study

## TL;DR

A 23-year-old man developed severe gastroenteritis from five different pathogens after a trip to Peru, highlighting the need for thorough testing in similar cases.

## Contribution

This case study reports a rare polymicrobial gastroenteritis involving five pathogens from a single travel-related exposure.

## Key findings

- Stool PCR testing identified five pathogens: Plesiomonas shigelloides, EAEC, EPEC, EIEC, and norovirus.
- The patient's symptoms resolved with intravenous fluids and antibiotics after two days of care.
- The case underscores the importance of comprehensive diagnostic testing for travelers with severe gastroenteritis.

## Abstract

Foodborne infections are a common cause of gastroenteritis, but cases involving multiple enteric pathogens from a single exposure are rarely reported. We present the case of a healthy 23-year-old male with no significant chronic medical history who developed febrile gastroenteritis after returning from a four-day solo trip to Peru. His symptoms began one day after returning and included fever, fatigue, nausea, vomiting, watery diarrhea, frontal headaches, and severe neck pain. His history was notable for a herniated disc from a motor vehicle collision (MVC) four months prior, for which he was undergoing physical therapy, raising initial concerns for a non-infectious cause of his neck pain. Initial workup revealed leukocytosis, tachycardia, acute kidney injury (AKI), and imaging concerning for a possible small bowel obstruction. Stool polymerase chain reaction (PCR) testing detected multiple enteric pathogens, including Plesiomonas shigelloides, enteroaggregative Escherichia coli (EAEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), and norovirus. The patient was treated with intravenous fluids, ceftriaxone, and metronidazole. His symptoms improved, and he was discharged after two days of supportive care. This case highlights the potential for polymicrobial enteric infections from brief travel-related exposures, emphasizing the need for comprehensive diagnostic testing in returning travelers with severe gastroenteritis.