Schistosomiasis (bilharziasis) and male infertility

Schistosomiasis (bilharziasis) is an endemic parasitic disease of a major source of morbidity and mortality for developing countries. It is caused by different species of blood flukes (trematode worms) of the genus Schistosoma, the most important of which are S. haematobium which infests the genitourinary tract and S. mansoni and S. japonicum which infest the gastrointestinal tract. The incidence of schistosome-induced male infertility is not known and probably underestimated being overshadowed by the more severe and often fatal urinary and gastrointestinal complications. Several causes may contribute to schistosomiasis-induced male infertility, such as hormonal imbalance, testicular tissue damage and genital ductal system obstruction, in addition to decreased libido and erectile dysfunction due to associated hormonal imbalance and prostatic infestation. Demonstration of the schistosome ova in seminal plasma or testicular tissue confirms the diagnosis. Treatment of schistosomiasis-induced male infertility depends on clinical evaluation and includes, besides anthelmintic treatment, hormonal replacement and assisted reproduction (IVF/ICSI) in cases of severe oligozoospermia and or obstructive and nonobstructive azoospermia.