Case #362 – December 2013

A 29-year-old female post-graduate student in Zoology went on an expedition to see the lowland gorillas in the Democratic Republic of Congo. She reported numerous insect bites while traveling but did take anti-malarial prophylaxis. Approximately one week after returning home she developed fever. About a month later, she started experiencing headaches, itchy skin, and swollen lymph nodes and sought medical attention. A blood specimen was collected; smears made and stained with Wright-Giemsa. The objects shown in Figures A–D were observed in moderate numbers. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

This was a case of African trypanosomiasis caused by a hemoflagellate belonging to the Trypanosoma brucei complex. Diagnostic morphologic features shown included:

trypomastigotes with a centrally located nucleus, an undulating membrane, and a flagellum running along the undulating membrane.
a small kinetoplast located on the anterior end of the trypomastigote.
dividing forms (Figures C and D).

This was most likely T. b. gambiense (although morphologically it is identical to T. b. rhodesiense), given the travel history to the DRC.