Chronic Diarrhea in a Traveler
Patient History
A 21-year-old male presents with a 6-week history of watery diarrhea and crampy abdominal pain. He reports that the diarrhea has not been constant and has alternated with periods of constipation. For the past 2 weeks, the diarrhea has been blood streaked, and he has had several weeks of mid-epigastric pain. He spent the last 6 months in a rural community in Guatemala participating in a community service project sponsored by his college. He returned from Guatemala just 10 days ago. While there, he drank the water and ate the food available in the local community, and he did not regularly boil the water for drinking. He denies antibiotic exposure but was taking mefloquine weekly for malaria prophylaxis. Two separate stool specimens taken by student health when he returned were reported as negative for Salmonella, Shigella, Campylobacter, E. coli 0157:H7, Yersinia, Aeromonas, and Plesiomonas, as well as Giardia lamblia. On physical examination, he appeared well-nourished and well-developed but reported an 8â10 pound weight loss. He was afebrile with a blood pressure of 110/80 mm Hg, pulse rate of 84/min, respirations of 14/min, and his lungs were clear. The abdominal examination was significant for tenderness localized to the right upper quadrant without rebound tenderness, but no mass or hepatomegaly was appreciated.
Travelerâs diarrhea is loose, watery diarrhea that occurs within the first week of arriving in a new country. The diarrhea is usually accompanied by nausea, vomiting, abdominal cramps, and fever; however, the disease is self-limited, and the average length of illness is 3â5 days. Because his symptoms have persisted for 6 weeks, the patient is unlikely to have travelerâs diarrhea. Infectious and noninfectious causes include bacteria, parasites, ulcerative colistis, diverticulitis, and carcinoma. As the symptoms have persisted longer than a week, consider parasites as an infectious cause.
Assignment
Provide a 1-page report on this case study. For the report, describe methods of appropriate specimen collection, examination of specimen, and a likely causative agent.
For the causative agent, describe pathogenesis of the organism, treatment, and prevention.
Under pathogenesis, describe how the agent is acquired, its reservoir, its life cycle, likely hosts, and infection process.
