Case 207. Trypanosomiasis (25 y-o F)
    Peripheral blood smear in a Brasilian, complaining of hemilateral swelling of the face and eye lid and lymphadenopathy (Romana's sign)    
Key words : 
Trypanosoma cruzi, parasitemia, Romana's sign, Trypanosoma gambiense    
Romana's sign is seen in acute infection of Trypanosoma cruzi. American trypanosomiasis, transmitted by Triatoma, is prevailing in central and south America.   C-shaped trypomastigotes of T. cruzi are seen in the peripheral blood (parasitemia). Usually, the clinical course is benign. Chronic trypanosomiasis is called Chagas disease (refer to case 231).
Trypanosoma gambiense in mouse blood (Giemsa)
African trypanosomiasis caused by T. gambiense or T. rhodesiense is known as "sleeping disease", resulting in lethal meningoencephalitis. The vector is tsetse fly (Glossina). It is dificult to identify protozoan parasites in tissue sections. The flagellated trypomastigotes of T. gambiense in the peripheral blood are larger than those of T. cruzi. Both the nucleus and kinetoplast (located at the rearest part of the body) are recognized.
  Trypanosoma cruzi in cultured HeLa cells (Giemsa)
Within the infected cells, it is difficult to distinguish Trypanosoma from Leishmania. The intracellular aflagellated form is called the amastigote. Trypanosomiasis of both American and African types is serious zoonosis, and is one of the 6 target disorders of WHO's TDR (tropical disease research and training) planning. The other 5 TDR disorders include leishmaniasis, malaria, schistosomiasis, filariasis and leprosy.