Finding hybrid schistosomes in genital schistosomiasis: are we missing their clinical relevance?

Genital schistosomiasis is a parasitic disease that affects both men and women as male and female genital schistosomiasis (MGS and FGS), respectively. Symptoms mimic sexually transmitted infections in men and women, owing to inflammation in the genital organs caused by migrating and trapped parasite ova. Schistosoma haematobium is the main causative organism, with an estimated 75% of infected women experiencing FGS, equating to approximately 56 million women mainly in sub-Saharan Africa. Estimates for MGS are mostly lacking, but numbers may be equivalent. S. haematobium has been found in hybridized forms with other Schistosoma animal species such as S. bovis, S. curassoni, S. mattheei and human schistosomes like S. mansoni. It is currently unclear what the impact of these species might be on genital schistosomiasis, including on clinical presentation, prognosis and management. In this review, we explore genital schistosomiasis and hypothesize the potential morbidity impact of hybrid species, along with highlighting future research needs. This article is part of the Royal Society Science+ meeting issue 'Parasite evolution and impact in action: exploring the importance and control of hybrid schistosomes in Africa and beyond'.