Parasitology Practical

Case Study #1: A patient comes to your clinic who just returned from a mission trip in Africa. Her laboratory results indicated 1+ proteinuria and rare RBC in the urinalysis report. The CBC indicated anemia and the differential report described the forms seen in the picture above. What is the scientific name of the parasite?

• Trypanosoma gambiense

• Leishmania sp.

• Plasmodium falciparum

• Trypanosoma rhodesiense

Case Study #1

What is the vector in this parasite's life cycle?

• mosquito

• tick

• Reduvid bug

• Tse tse fly

Case Study #1

What diagnostic form is on the microscope?

• amastigote

• promastigote

• ring form

• cyst

Case Study #2: A 22 year old woman was admitted to the emergency department at 3:00 a.m. complaining of burning during urination and severe vaginal itching. The physician ordered a routine urinalysis and a vaginal swab for microscopic examination. The technologist observed many motile organisms measuring approximately 12μm in diameter in both the urine microscopic exam and the vaginal wet mount preparation. What is significant in the patient's history that will help you make the differential diagnosis?

• gender

• burning during urination and severe vaginal itching

• 3:00 am visit to the ER

• age

Case Study #2

What is the name of the organism most likely causing the disease?

• Giardia lamblia

• Trichomonas hominis

• Trichomonas vaginalis

• Entamoeba histolytica

Case Study #2

How is this disease typically transmitted?

• sexual contact

• wearing too tight of clothing

• genetic

• airborne

Case Study #3

1.       A mother, working outside the home, took her 2 year old son on the third day of his illness to his pediatrician.  The child had diarrhea and vomiting that became progressively worse over the 3 day period.  The watery stool specimen sent to the laboratory revealed no white or red blood cells when examined for parasites, but the technologist noted many refractile organisms measuring approximately 5 µm that resembled yeast.  A modified acid-fast stain revealed acid-fast organisms shown in the accompanying figure.  (The parasites are staining pink/red and the background is blue).

What is significant in the patient history?

• age of patient

• diarrhea & vomiting

• gender of patient

• mom works outside the home

Case Study #3

What is the name of the organism causing the disease?

• Giardia bovis

• Giardia lamblia

• Cryptosporidium parvum

• Toxoplasma gondii

Case Study #3

What was the likely source of the infection?

• dirt

• contaminated food

• water

• mosquito borne

Case Study #4

Two 16 year old boys returned from a 4 week camping trip in the northwest United States.  For 2 weeks after the trip, both boys experienced abdominal cramps and diarrhea, usually within 1 hour after eating.  Foul-smelling flatulence was present as well.  On questioning, the boys denied drinking water that was not treated with halzone tablets (a chloramine disinfectant used to purify water).  Three of their stools were submitted for culture and identification of enteric bacterial pathogens and intestinal parasites.  All the results were negative for bacterial pathogens and only one trichrome stain from one sample revealed the parasite form seen in the accompanying figure.

What is the name of the organism most likely causing this disease?

• Giardia lamblia

• hookworm

• Entamoeba histolytica

• Trichomonas hominis