Pathology Notes

Practice questions answers 2 Infectious gastroenteritis © Jun Wang, MD, PhD   1. F. This case is characterized by profuse watery diarrhea and signs of dehydration. The diarrhea is watery containing whitish material, forming a rice water appearance. These features are consistent with cholera . Diarrhea caused by campylobacter , Shigella and entamoeba histolytica is usually bloody. The watery diarrhea associated with enterotoxigenic e coli , giardia intestinalis or norovirus usually does not have abundant mucus in the stool, nor severe dehydration, as seen in cholera .   2. E. Low blood pressure can be caused by many factors, as those seen in shock . However, the low blood pressure in patients with cholera is associated with loss of circulating volume, resulted from fluid loss through profuse diarrhea.   3. E. While the presentations of high grade fever, frequent, small-volume bloody stools with travel history are highly suggestive of Shigella infectio...

Practice questions answers 1 Infectious gastroenteritis © Jun Wang, MD, PhD   1. D. The symptoms described in the case, including mild to moderate mid-abdominal cramps, nausea, vomiting, and watery diarrhea after attending a social gathering at a seafood restaurant, are suggestive of a foodborne illness. Although many pathogens may cause diarrhea, the mild presentations are most likely associated with norovirus infection. The major pathogenetic pathway for norovirus induced diarrhea is malabsorption. Activation of guanylate cyclase and efflux of Cl – and H 2 O is seen in enterotoxigenic e coli diarrhea and cholera . However, enterotoxigenic e coli usually do not have vomiting. Cholera usually presents with severe diarrhea with rice water appearance and signs of dehydration. While colonization of giardia intestinalis can be seen in duodenum and jejunum, they do not invade mucosa.    Suppression of normal colonic flora is associated with clostridium difficile...

Practice questions 2 Infectious gastroenteritis ©Jun Wang, MD, PhD   1. Use this case and image for next 2 questions . A 41-year-old man presents to the emergency department with vomiting, diarrhea, and leg cramps for a day. He recently returned from a trip to a developing area and consumed seafood from street vendors. He appears critically ill and sluggish in communicating. His blood pressure is 85/55 mmHg, heart rate is 140 beats per minute. His eyes are sunken, and his skin and oral mucosa are dry. Laboratory tests reveal a hematocrit of 60% (normal 40-54%) and a serum bicarbonate level of 18 mmol/L (normal range: 22-28 mmol/L). An image of his stool is shown. What is the most likely pathogen?   (Image credit: F1jmm, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons) A. Campylobacter jejuni B. Entamoeba histolytica C. Enterotoxigenic E. coli D. Giardia intestinalis E. Shigella F. Vibrio Cholerae   2. A ...

Practice questions 1 Infectious gastroenteritis © Jun Wang, MD, PhD   1. Use this case for next 3 questions . A 19-year-old woman presents to the emergency department with mild to moderate mid-abdominal cramps, nausea, vomiting and watery diarrhea twice in the past 4 hours. She reports attending a social gathering the previous day at a local sea food restaurant. Her past medical history is unremarkable. She appears alert but a little bit tired. Her vital signs are within normal ranges. She has mild lower abdominal tenderness and hyperactive bowel sounds. No abdominal guarding is noted. Her stool is watery and negative for blood components. Other laboratory results are unremarkable. What is most likely the cause of her diarrhea? A. Activation of guanylate cyclase B. Efflux of Cl – and H 2 O C. Invasion of jejunal mucosa D. Malabsorption E. Suppression of normal colonic flora   2. A 19-year-old woman presents to the emergency department with mild to moderate...