Effects of Trypanosoma vivax and Trypanosoma congolense infections on the reaction time and semen characteristics of Zebu (Bunaji) x Friesian crossbred bulls.

The effect of trypanosomosis on reaction time and semen characteristics of 12 Zebu (Bunaji) x Friesian crossbred bulls aged between 3 and 5 years was studied for a duration of 12 weeks. Four of the bulls were infected with Trypanosoma vivax, another four with Trypanosoma congolense and the remaining four bulls served as controls. Rectal temperatures and haematological parameters were monitored twice weekly. The pre-infection mean value of the rectal temperature was 38.3 degrees C, and this rose to a mean of between 40.5 and 41.1 degrees C in the infected animals. Concurrently, the infected animals exhibited signs of anaemia shown by pale mucous membranes and decreased packed cell volume (PCV), weight loss, lethargy, weakness and dullness. The reaction time (ejaculation time) of semen collection significantly increased from a pre-infection mean value of 20.46-25.14 s to a mean of 290.33-301.15 s within 12 weeks post-infection. Semen characteristics deteriorated progressively within the same period in the infected bulls. There were highly significant and drastic decreases in sperm concentration and volume of semen and increases in sperm morphological defects. By the third week, all the infected bulls were unfit for breeding because of very poor semen characteristics. Deterioration, also characterized by oligospermia at 6 weeks post-infection in all bulls which later culminated in azoospermia in two bulls infected with T. vivax and two bulls infected with T. congolense continued to the end of the investigation. The present results indicate that trypanosomosis due to T. vivax and T. congolense infections is very pathogenic and devastating in its effect on the reaction time (ejaculation time) and semen characteristics which resulted in very poor semen quality. The practical implication is infertility and sterility in Zebu x Friesian crossbred bulls in trypanosome endemic areas.

Microsurgical epididymal sperm aspiration with motile trophozoite cells but no spermatozoa.

This paper reports on a patient in whom the clinical diagnosis of obstructive azoospermia was made according to clinical observations, i.e. azoospermia, normal andrological examination, normal follicle stimulating hormone and a misleading histopathological report of a testicular biopsy. Microsurgical vasoepididymostomy failed to restore fertility, and as a last resort, microsurgical sperm aspiration was performed. Although flagellated cells were observed in the epididymal aspiration, no spermatozoa were observed and wet preparation of multiple testicular biopsies failed to demonstrate any spermatozoon. This patient was diagnosed to have a non-obstructive azoospermia, resulting from maturation arrest associated with trichomonas infection at the level of the epididymis.