Detection of male genital schistosomiasis (MGS) associated with human, zoonotic and hybrid schistosomes in Southern Malawi

Abstract

Abstract Background Male Genital Schistosomiasis (MGS) remains an often-overlooked chronic sequela of urogenital schistosomiasis in endemic areas of sub-Saharan Africa. As part of a 2-year longitudinal study on Hybridization of UroGenital Schistosomiasis (HUGS) in Malawi, a MGS sub-study was conducted to assess whether hybrid schistosomes were incriminated. Methods During recruitment, demographic, health and socio-economic data were collected through individual questionnaire interviews in Mthawira community from Nsanje District along Shire River and Samama community from Mangochi District along Lake Malawi shoreline. Urine and semen samples were collected and analysed to determine the identity of schistosome infection. Urine filtration and microscopy, direct microscopy of semen and its sediments (after centrifugation) were performed. Thereafter, the sediments were examined by molecular DNA analysis with a novel two-tube real-time PCR assay. The participants were also screened for Human papilloma virus (HPV) and other sexually transmitted infections (STIs). Results Twenty-two men were recruited for the sub-study, 8 in Nsanje District and 14 in Mangochi District, with a median age of 22.0 years. By microscopy, ten (45.7%) participants had Schistosoma ova in their urine, 11 (50.0%) in semen while 16 (72.7%) were positive by real-time PCR. One participant had both S. haematobium and S. mattheei ova in his semen, three showed symptoms, and one had a mixed infection of S. mansoni and possible S. haematobium-S. mattheei hybrid. Twelve men had detectable high-risk HPV serotypes 16, 18 and others while six had Trichomonas vaginalis and other STIs. Conclusion Zoonotic and hybrid schistosomes can cause MGS similar to human schistosomes, which can be co-infected with HPV and STIs, thereby posing a new challenge in diagnosis, management and control measures in resource poor settings. Increased awareness of these infections among local communities and primary healthcare workers and improvement of disease management are needed and advocated.

Keywords

• Lake Malawi
• Shire River
• Urogenital schistosomiasis
• Schistosoma haematobium
• Schistosoma mattheei
• Semen