Page 154 - parasitology for medical and clinical laboratoryprofessionals

134 CHAPTER 5

CASE STUDIES

1. A young enlisted sailor has been living on the local economy in Thailand while
attached to a U.S. embassy. Two months after his posting at the facility, he reported
to the medical treatment facility complaining of diarrhea and somewhat severe ab-
dominal pain. A stool specimen was cultured for pathogenic bacteria and yielded
normal results. Upon his return to the treatment area an additional stool specimen
was obtained and examined microscopically. Large operculated eggs that were broad
and elliptical in shape were observed. What is the probable causative organism and
what is another parasite that could be confused with the most probable diagnosed
pathogen?
2. A female graduate student had worked and studied on Lake Victoria in Kenya for the
past semester. Abdominal and flank pain spurred her to visit her physician. She denied
any history of renal calculi in her family as well as abnormalities of the kidneys. A urine
culture revealed no bacterial presence in the specimen but the urinalysis showed an
abnormal level of protein as well as red blood cells and oval structures with terminal
spines. What is the probable causative organism and how was the probable species
determined?
3. A 58-year-old professor of sociology had returned from a vacation in Africa, where he
began experiencing episodes of chills followed by fever. While considering a systemic
viral infection, the physician ordered a complete blood count with thick and thin
smears. The patient remembered that his urine had slowly darkened over the past
few weeks and the blood count showed mild anemia. What disease was more than
likely causing the symptoms and signs? What are some other parasites that may be
diagnosed by study of blood smears?

STUDY QUESTIONS

1. What are the three classes of helminthes, the 8. The organism of the genus that causes a disease
worms, of parasitology? called bilharziasis is:
2. Name the three scientific names of worms that 9. Symptoms and signs of schistosomiasis are:
infect predominantly cats and dogs. 10. Complications of schistosomiasis that impact the
3. Name the two species of hookworm that infect liver may include:
humans in both the New and Old World. 11. A severe immunological reaction in the host
4. List the clinical symptoms and signs for hookworm who has contracted schistosomiasis and is life-
infections. threatening may include:
5. Nearly all trematodes are obligate parasites of 12. Where are the infective cercaria found in endemic
____________ and _____________________. areas of schistosomiasis?
6. Nearly all flat worms are also known as 13. What is the common name for a threadworm
______________. infection in children?
7. Flatworms or flukes can be classified into two 14. Besides an itchy anus at night, what are other signs
groups. They are: and symptoms of pinworm infection?