Revealing bovine schistosomiasis in Malawi: Connecting human and hybrid schistosomes within cattle.

In Malawi, the putative origin of a newly described - hybrid human schistosome was assessed upon a seminal molecular parasitological survey of cattle. Using miracidia hatch test (MHT) and carcass inspection at slaughter, mean prevalence of bovine schistosomiasis was 49.1% (95% CI: 43.7-54.6%) and 10.3% (95% CI: 6.0-16.2%) respectively, though significant spatial heterogeneity was noted. Approximately 2.0% of infected cattle, and only those from Mangochi District, shed - and/or in faeces. To quantify schistosome (re)infection dynamics, where a - hybrid was present, we undertook a novel pilot GPS-datalogging sub-study within a specific herd of cattle (  = 8) on the Lake Malawi shoreline, alongside a praziquantel (40 mg/kg) treatment efficacy spot check. At sub-study baseline, all GPS-tagged cattle had proven daily water contact with the lake. Each animal was patently infected upon MHT, with older animals shedding less miracidia. At one month review, whilst parasitological cure was 100.0%, from six weeks onwards, (re)infection was first noted in the youngest animal. By three-month review, all animals were patently (re)infected though only miracidia of were recovered, albeit in much lower numbers. To conclude, infection with is particularly common in cattle and demonstrates a previously cryptic burden of bovine schistosomiasis. Within Mangochi District, bovine transmission of both - hybrids and are now incriminated, with unequivocal evidence of contemporary zoonotic spill-over. Future control of urogenital schistosomiasis here in the southern region needs to develop, then successfully integrate, a One Health approach with appropriate mitigating strategies to reduce and/or contain bovine schistosomiasis transmission

Development, validation, and pilot application of a high throughput molecular xenomonitoring assay to detect Schistosoma mansoni and other trematode species within Biomphalaria freshwater snail hosts

Schistosomiasis is a neglected tropical disease (NTD) caused by infection with parasitic trematodes of the genus Schistosoma that can lead to debilitating morbidity and mortality. The World Health Organization recommend molecular xenomonitoring of Biomphalaria spp. freshwater snail intermediate hosts of Schistosoma mansoni to identify highly focal intestinal schistosomiasis transmission sites and monitor disease transmission, particularly in low-endemicity areas. A standardised protocol to do this, however, is needed. Here, two previously published primer sets were selected to develop and validate a multiplex molecular xenomonitoring end-point PCR assay capable of detecting S. mansoni infections within individual Biomphalaria spp. missed by cercarial shedding. The assay proved highly sensitive and highly specific in detecting and amplifying S. mansoni DNA and also proved highly sensitive in detecting and amplifying non-S. mansoni trematode DNA. The optimised assay was then used to screen Biomphalaria spp. collected from a S. mansoni-endemic area for infection and successfully detected S. mansoni infections missed by cercarial shedding as well as infections with non-S. mansoni trematodes. The continued development and use of molecular xenomonitoring assays such as this will aid in improving disease control efforts, significantly reducing disease-related morbidities experienced by those in schistosomiasis-endemic areas

Challenges in the diagnosis and control of female genital schistosomiasis in sub-Saharan Africa: an exemplar case report associated with mixed and putative hybrid schistosome infection in Nsanje District, Southern Malawi

Female genital schistosomiasis (FGS) remains an often overlooked chronic complication of urogenital schistosomiasis in adolescent girls and women. Moreover, the role of zoonotic or hybrid schistosome infection(s) is poorly appreciated, but is increasingly becoming an emerging public health concern in sub-Saharan Africa. In Southern Malawi, during the “Hybridization in UroGenital Schistosomiasis (HUGS)” study visit, we describe the case of a 33-year-old woman with suspected FGS who partook in a detailed external assessment with internal cervical examination using a portable colposcope. She provided several biological samples for analysis with traditional and molecular parasitological methods—urine, cervicovaginal lavage (CVL), cervical swabs, and external mass and cervical biopsies—alongside provision of detailed demographic information after a thorough medical history questionnaire and an in-depth interview. These samples were screened for the presence of Schistosoma ova on microscopy and DNA genotyping using a novel real-time PCR assay in parallel to pre-published probe-based PCR assays capable of identifying and discriminating up to six named Schistosoma species. A further molecular screen of sexually transmitted infections (STIs) including Trichomonas vaginalis, Chlamydia spp., and human papilloma virus (HPV) was conducted on her genital swab and CVL. Overt FGS was diagnosed on clinical colposcopy alongside inspection of the cervical biopsy by microscopy, real-time PCR, and histopathology. The urine filtration, microscopy and real-time PCR of the CVL and swab were negative. This evidences the typical diagnostic challenge, and cases such as this will pose an unmet need in satisfactory patient management. In addition to Schistosoma haematobium, the presence of the zoonotic species Schistosoma mattheei and concurrent STIs raise questions as to the long-term effectiveness of the current control strategies of the National Control Programme to eliminate schistosomiasis as a public health problem. Improved availability of and regular accessibility to praziquantel treatment for women at risk such as this are urgently needed. Furthermore, targeted health education, increased community awareness, and dovetailing of synergistic activities and strategies with other health stakeholders such as those in sexual and reproductive health, as well as HIV/AIDS programs in the Ministry of Health, are needed here and in neighboring countries

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

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

Challenges in the diagnosis and control of female genital schistosomiasis in sub-Saharan Africa: an exemplar case report associated with mixed and putative hybrid schistosome infection in Nsanje District, Southern Malawi

Female genital schistosomiasis (FGS) remains an often overlooked chronic complication of urogenital schistosomiasis in adolescent girls and women. Moreover, the role of zoonotic or hybrid schistosome infection(s) is poorly appreciated, but is increasingly becoming an emerging public health concern in sub-Saharan Africa. In Southern Malawi, during the “Hybridization in UroGenital Schistosomiasis (HUGS)” study visit, we describe the case of a 33-year-old woman with suspected FGS who partook in a detailed external assessment with internal cervical examination using a portable colposcope. She provided several biological samples for analysis with traditional and molecular parasitological methods—urine, cervicovaginal lavage (CVL), cervical swabs, and external mass and cervical biopsies—alongside provision of detailed demographic information after a thorough medical history questionnaire and an in-depth interview. These samples were screened for the presence of Schistosoma ova on microscopy and DNA genotyping using a novel real-time PCR assay in parallel to pre-published probe-based PCR assays capable of identifying and discriminating up to six named Schistosoma species. A further molecular screen of sexually transmitted infections (STIs) including Trichomonas vaginalis, Chlamydia spp., and human papilloma virus (HPV) was conducted on her genital swab and CVL. Overt FGS was diagnosed on clinical colposcopy alongside inspection of the cervical biopsy by microscopy, real-time PCR, and histopathology. The urine filtration, microscopy and real-time PCR of the CVL and swab were negative. This evidences the typical diagnostic challenge, and cases such as this will pose an unmet need in satisfactory patient management. In addition to Schistosoma haematobium, the presence of the zoonotic species Schistosoma mattheei and concurrent STIs raise questions as to the long-term effectiveness of the current control strategies of the National Control Programme to eliminate schistosomiasis as a public health problem. Improved availability of and regular accessibility to praziquantel treatment for women at risk such as this are urgently needed. Furthermore, targeted health education, increased community awareness, and dovetailing of synergistic activities and strategies with other health stakeholders such as those in sexual and reproductive health, as well as HIV/AIDS programs in the Ministry of Health, are needed here and in neighboring countries