CASE 2

A family of three, with a 7-year-old son, takes a three-week tour of rural Mexico. They are careful about drinking only bottled beverages, but they frequently take their drinks on ice, and they use the local tap water when brushing their teeth. During the third week of their trip, they all experience mild abdominal cramps and diarrhea that persist for two days before clearing up. Two months after returning to the U. S., their son begins to experience abdominal pain. He also has a persistent fever and a dull pain in the right upper quadrant. When the symptoms fail to subside after three days, the family goes to their primary care physician to seek advice. The boy's vital signs are pretty-much normal except for a fever of 38.5ºC. Upon physical examination, the boy is found to have hepatomegaly and point tenderness over the liver. Otherwise, the examination is unremarkable. The physician asks if any other family members have been ill and learns that the father has been experiencing recurrent periods of mild fever. He has also lost about 14 pounds in the last month or so, even though he hasn't been making a special effort to diet. The father did not seek medical advice because the fever wasn't all that noticeable and he figured that he needed to lose weight anyway. The mother has no noticeable signs or symptoms of disease. On physical examination, the farther is found to have a slight fever (38ºC) and signs of hepatomegaly. There are no other remarkable findings.

Question 2.1: What is your preliminary diagnosis for the boy's illness?

Question 2.2: What tests should you perform?

Question 2.3: What is the final diagnosis? How can it be confirmed?

Question 2.4: Are the father's symptoms related to those of his son?

Question 2.5: What complications are possible?

Question 2.6: How does this causative agent damage the liver?

Question 2.7: How can this disease be treated?

CASE 3

A 17-year-old boy from Kansas decides to spend his summer in Australia, working on his uncle's sheep ranch. (It's actually winter in Australia at that time of the year, but this has nothing to do with the case.) About one month into his visit, the boy begins to experience pain in the upper right quadrant, along with chills and fever. These symptoms persist over several days, so he his taken to the local physician. On examination, he is found to have fever (38.5ºC), point tenderness over the liver, and pronounced hepatomegaly. The doctor asks him if he has consumed uncooked sheep liver or watercress since arriving in Australia. The boy says that he saw watercress growing in a pond on the farm and ate some of it because he is fond of it and eats it frequently in the U.S. In fact, he found it odd that his Australian family never used it in their salads, but he didn't want to say anything because he was a guest. On hearing this, the physician examines a stool sample microscopically, but he fails to find anything remarkable. At that point, he sends the boy to the nearest hospital for a CT scan of his liver and other tests. The scan reveals the presence several small track-like features that do not appear to be normal. A CBC shows a marked eosinophilia.

Question 3.1: What is the most likely diagnosis?

Question 3.2: What is the life cycle of this pathogen?

Question 3.3: How is this disease transmitted?

Question 3.4: What may happen if this case is not treated?

Question 3.5: How is this disease treated?