Abstract
African trypanosomiasis is caused by the protozoan parasite Trypanosoma brucei, transmitted between mammals by the bite of a tsetse. It has been recently shown that parasites accumulate in large numbers in various organs and tissues, including the mouse testis. Whether parasites are protected from the immune system in the male reproductive organ or can be transmitted through sexual route remains unknown. Here we show that parasites can be detected by fine needle aspiration cytology of the male reproductive system in mice, and histopathological analysis revealed that T. brucei accumulates in the stroma of the epididymis, epididymal adipose tissue and fibrous tunics of the testis. No parasites were found in the lumen of intact epididymal ducts or seminiferous tubules of the testis, indicating that the large majority of the parasites are not located in immune-privileged sites. In fact, these parasites are associated with marked inflammatory cell infiltration, parasite degeneration, and severe tissue damage and rupture of epididymal ducts, which may be related with reduced fertility. Overall, we show that just like in the bloodstream and most other tissues, in the male reproductive organs, T. brucei are exposed to a strong immune response. The detection of a very high number of parasites in this organ and its accessibility opens the possibility of using fine needle aspiration cytology as a complementary diagnostic tool in Animal African Trypanosomiasis.
Highlights
Human African Trypanosomiasis (HAT), known as sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei [1]
The protozoan parasite Trypanosoma brucei is the causative agent of African trypanosomiasis in humans and animals
For fine needle aspiration cytology (FNAC), mice were positioned in dorsal recumbence and a 21-gauge needle connected to a 5 mL-syringe was halfway inserted into each testis and epididymis, which were gently aspirated; the withdrawal fluid was smeared, airdried, immunostained for VSG and examined under light microscopy
Summary
Human African Trypanosomiasis (HAT), known as sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei [1]. HAT evolves through different clinical stages and often leads to death if left untreated. It is broadly characterized by an early/hemolymphatic stage and a late/encephalic stage. Rhodesiense causes a fulminant, acute disease and is mainly found in east Africa [2]. Cattle are affected by Animal African Trypanosomiasis (AAT, commonly known as nagana), which generally involves fever, emaciation and anemia, and which can be fatal if left untreated [3]. AAT is one of the most important infectious diseases that limit livestock production in sub-Saharan Africa, with an estimated cost in Eastern Africa of US$2.5 billion [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
