September, 2002

Case 91:
A 37-year-old man was admitted to the hospital for fever and an inflamed foot.  He had spent the previous 3 months touring South America, southern and eastern Africa, and Kathmandu.  Ten days before admission, he visited game reserves in Tanzania, where he reported multiple tsetse fly bites.  Six days later, he developed pain in the left foot and high fever.  The next day, he noted progressive swelling on the dorsum of the foot and he was evaluated at a clinic in Katmandu.  A malaria smear was negative and he was prescribed cephalexin.  He continued to have intermittent high fever (to 41°C [105.8°F]) and developed vomiting, headache, myalgia, and a diffuse rash.  A repeat malaria smear was negative, but his white cell count was 4000 per mm³ with 10% band forms.  He returned to the United States and was admitted to the hospital.  A shallow ulceration was present on his left instep, encircled by bullae at the margin and surrounded by purple discoloration.  The foot lesion was 5 cm in diameter.  Following is a video clip of a wet preparation of his blood.  What is your diagnosis?  Based on what criteria?

After the video clip (Adobe Flash format) plays through one time, you can right click on the image and choose play to watch the video again.

Click here for the answer to Case 91.

Case 92:
A patient received 9 separate units of packed red blood cells (3 times in March, 3 times in late May, and 3 times in late June).  The patient developed flu-like symptoms 5 days after the last transfusion.  The patient had no history of travel outside the continental United States.  Thick and thin blood smears of the patient’s blood were stained with Giemsa and examined.  The following images show the objects seen in the blood smears.  What is your diagnosis?  Based on what criteria?

During the follow-up investigation, a total of 9 different blood donors were identified.  Blood smears were prepared from the donated blood, stained and examined for parasites.  All 9 smears were negative (no parasites found).  What additional diagnostic tests would you recommend to identify the infected donor and why?

A	B

C

Click here for the answer to Case 92.

Images presented in the monthly case studies are from specimens submitted for diagnosis or archiving.  On rare occasions, clinical histories given may be partly fictitious.