Of Pigs and People on the Potomac

1
A

• THE CASE
• Tarhuni, a second-generation American of
  Mediterranean descent, liked animals. He even
  enjoyed working with the small collection of
  pigs his father reared for the local market. He
  could not understand how anyone could eat such
  intelligent, friendly beasts. He gave each of
  them a name and called their names as he petted
  them at their mealtimes. The pigs feelings
  seemed mutual they would nuzzle his hands now
  and then while eating, kissing them in what
  Tarhuni interpreted as expressions of gratitude.
  He overlooked the juicy mixture they applied to
  his hands.
• As a biology major Tarhuni avidly joined the
  student/faculty spring camping trip to the
  headwaters of the Potomac, a few hours drive from
  the college, which was only a few kilometers from
  his fathers farm. He quickly siezed the
  opportunity to see even more animals, perhaps
  even a bear, even though his group was supposed
  to camp in a relatively bear-free area. He had
  never seen a bear in the wild.
• The first day at camp went well. Tarhuni and
  his colleages even spotted a black bear through
  binoculars on a ridge across the small valley
  near their campsite. He was a very happy camper.
• That evening after a delicious meal made even
  better by the roasted marshmallows and fresh
  mountain air, Tarhuni fell ill. One student
  mentioned that she thought Tarhuni had a yellow
  tint in his eyes. Others extended hands to check
  his temperature. All the while the faculty
  members and biology club president conferred on
  what should be done. Everyone else appeared to
  be fine so, it was agreed that Tarhuni would be
  taken to the nearby town where a doctor would be
  sought to examine him. They would go from there.
• Fortune shone as brightly as the mountain
  moonlight because the small village they drove to
  did indeed have a doctor, who, without
  hesitation, agreed to see the young man right
  away.
• Dr. Jim Bridger, who looked as if he might be
  ready to traipse off into the mountains on a
  trapping expedition at a moments notice, had
  very little modern equipment in his small clinic,
  but he had lots of experience in medicine and he
  did have a computer that was connected to the
  Internet and a cornucopia of complex data. He
  began by asking Tarhuni questions.
• He inquired about what Tarhuni had eaten in
  the last few days. The doctor next asked him
  about his sexual history. Tarhuni shyly told the
  doctor that he practiced abstinence because of
  his familys faith, which he tried to follow very
  closely. Then the ineluctable travel query
  arose Have you travelled outside the United
  States within the last year or so? Doctor
  Bridger asked. Only to Mexico, Tarhuni
  responded weakly.
• After a few more questions the doctor tried to
  make Tarhuni comfortable and retreated to his
  little library of old books and his computer.
• After what must have seemed hours to Tarhuni,
  the doctor returned and gave his presumptive
  diagnosis of Hepatitis E, a viral disease.
  Tarhuni would have to be transported immediately
  to the Metropolitan Regional Hospital.
• CASE ANALYSIS
• Recognize major topics and potential issues in
  this case. What does the case concern? Make a
  list of several things you think should be
  investigated or questions you think the case
  leads you to ask.

Of Pigs and People on the Potomac
Cole Benton Mark Bergland Karen Klyczek Chi-Cheng
Lin
B
C
Human Taiwan
Figure 2. Comparison of human and swine HEV
sequences from UK. A) DNA distance matrix for
data in B. B) Unrooted tree using data from C. C)
Data published in Banks et al., 2004,
demonstrating a high degree of similarity between
the HEV sequence isolated from a 58-year old
female patient and HEV isolated from two UK pigs.
Swine Taiwan
Swine US
Human US
Human US
Swine US
Swine Taiwan
Figure 1.a
Human Taiwan
What do we know? Hepatitis causes liver
problems. There was a serious outbreak of HEV
in Sudan, associated with the Darfur
conflict. There doesnt seem to be much press
devoted to HEV outbreaks in the U.S.
What do we need to know? How serious is the
pathology of this disease? What parts of the
world are most affected by HEV? Who is most at
risk for this disease? How is HEV transmitted?
Can animals like pigs be a source of this
disease? How similar are the sequences
between swine HEV and human HEV?
Figure 1.b

• References
• Anderson, D.A. and Shrestha, I.L. 2002.
  Clinical Virology, ASM Press,
• http//www.ilshrestha.com.np/research/hepatitis.ht
  m
• Banks, M et al. 2004. Emerging Inf Dis. 10(5),
  http//www.cdc.gov/ncidod/Eid/vol10no5,03-0908.htm
  
• Hsieh, S-Y et al. 1999, J. Clin. Micro. 37(12),
  3828-3834
• Meng, X-J et al. 1997 PNAS USA 94(18), 9860-9865
• Natl. Center for Biotechnology Information,
  http//www.ncbi.nlm.nih.gov
• San Diego Supercomputing Center, Biology
  Workbench, http//workbench.sdsc.edu

2
(No Transcript)