{"paper_id":"f0eb8357-814d-4f52-8880-a7525e9ecf01","body_text":"Schistosomiasis is endemic in sub-Saharan Africa where close to 205 million people are infected and many more are at risk of infection [ 1 ]. The most vulnerable are children and women who frequently come into contact with snail-infested water while playing, or in the course of their daily chores [ 2 ]. Despite current treatment efforts with mass drug administration using praziquantel, re-infections and chronic infection occur leading to morbidity that may last for decades, including Female Genital Schistosomiasis (FGS) [ 3 – 5 ].\nAll the human  Schistosoma  species may deposit ova in the genitals, sometimes denoted “ectopic schistosomiasis”.  S .  mansoni  ova, usually located in the lower gastrointestinal tract, are sometimes also found as far as the urinary tract and it is hypothesized that ova travel from the intestinal tract to the genital organs through blood vessel anastomoses in the pelvis [ 6 , 7 ]. However, lower genital tract lesions have almost exclusively been reported from  S .  haematobium  infected women [ 8 – 14 ]. FGS affects an estimated 56 million women worldwide [ 15 ].\nKenya is endemic for both the intestinal form (caused by  S .  mansoni ) and the urogenital form (caused by  S .  haematobium ) of schistosomiasis, with an estimate of approximately 9 million people infected and approximately 17.4 million at risk [ 16 ].  S .  haematobium  infection manifests itself with bloody urine, pain on urination, and higher risk of bladder cancer, genital symptoms and lesions [ 13 , 17 ]. The lower genital tract manifestations in women are grainy sandy patches, homogenous yellow patches, rubbery papules, abnormal blood vessels and mucosal bleeding of the surfaces, both in the vagina wall and on the cervix [ 18 ]. FGS is associated with decreased fertility, ectopic pregnancies, abdomino-pelvic pain, genital itch, dyspareunia, foul smelling discharge, and has been found to be associated with HIV [ 19 – 23 ].\nThere are a number of case reports of  S .  mansoni  ova in the genital tract and it has been hypothesized that it could lead to similar lower genital tract morbidity [ 24 – 26 ]. However, only a paucity of studies have explored this. A study in Brazil, where only  S .  mansoni  is endemic, found no genital tract morbidity due to schistosomiasis [ 27 ], but  S .  mansoni  infection intensity was low and participants had received repeated praziquantel treatment. A second study by Downs and others in an area endemic for both  S .  haematobium  and  S .  mansoni  in Tanzania reported that 5% of the women had  Schistosoma  ova in cytology smears, but the authors did not differentiate the cases according to  Schistosoma  species and genitalia were not inspected for lesions [ 28 ]. Interestingly, the prevalence of HIV was higher in the  S .  mansoni  villages than in the  S .  haematobium  villages [ 28 ]. A qualitative study in western Kenya found that genital health problems were reported among women exposed to  S .  mansoni , but no diagnostic tests were done and there was no control group [ 29 ]. Cunin  et al  found that people with very high infection intensity of dual infection with  S .  mansoni  and  S. haematobium  made it more likely to find  S .  mansoni  ova in urine, possibly as a result of “worm over-crowding” [ 7 ].\nHIV/AIDS is a leading cause of death in Kenya and is disproportionately high in Nyanza, western Kenya along the shores of Lake Victoria [ 30 , 31 ], an area that also has a high prevalence of  S .  mansoni  [ 32 – 35 ]. Based on these observations and the hypothesis that  S .  mansoni  may also be a risk factor for HIV [ 28 ], we sought to explore the prevalence of FGS in a  S .  mansoni -endemic area, investigate if  S .  mansoni  causes lesions in the lower genital tract, and characterize the gynaecological symptoms in women with  S .  mansoni  infection.\n\nApproval for the study was obtained from the Kenya Medical Research Institute (KEMRI) Scientific Steering Committees as well as the KEMRI National Ethical Review Committee (KEMRI SSC # 2937). Consent documents and participation information were approved and provided to potential study participants in English or the local language, Dholuo. The local authorities and health professionals were informed about the study. Informed written consent was obtained from each participant. A unique coded identification number was assigned to each subject and was used for sample tracking. All identifiers were delinked from data for the analysis. Privacy and confidentiality were strictly maintained. The risks of the study were minimal, with only the temporary discomfort and brief embarrassment associated with the gynaecological examination. All participants were treated with 40 mg/kg praziquantel (PZQ) and those infected with soil-transmitted helminths (STHs) were treated with 400 mg albendazole. In addition, treatment was provided in accordance with the Kenyan syndromic management protocol for sexually transmitted infections (STI). Results and treatment were delivered privately to the participant by a local professional nurse immediately after the study procedures.\nThe study was conducted in Rachuonyo North and Kisumu West sub-counties ( Fig 1 ), western Kenya in November 2015. The area is characterized by a modified equatorial climate. It is generally warm and humid with the long rains falling from March to May and the short rains between August and November/December, with an average annual temperature of 25°C. In this study, we focused on villages that are within a 5 km distance from Lake Victoria, where  S .  mansoni  prevalence is the highest [ 36 ]. Together with other sub-counties bordering the lake, the region has the highest prevalence of HIV/AIDS (15.1%) in Kenya amongst persons aged 15–64 years [ 30 ]. The exact HIV prevalence in the selected communities was not known, however the overall prevalence of HIV in Kisumu was 16.3% [ 37 ]. The chief mode of HIV transmission is thought to be via heterosexual intercourse [ 38 , 39 ].\n(A) Kisumu West and (B) Rachuonyo North sub-counties,  https://opensource.com/ .\nThe majority of the population consisted of the Luo ethnic community who were at risk of infection with  S .  mansoni  through their occupational or recreational activities. This cross-sectional study focused on 18–50 year old women. At the time of the study, mass drug administration for schistosomiasis control was unavailable for adults in this endemic area.\nWomen were approached at home by a community health worker to introduce the study and invite potential participants on a specific date to a specified health facility in their community. The investigators held information meetings and sought consent. Women who were not observably ill, were willing to take part in the study, and to provide the requested samples (stool, urine, blood, and intra-vaginal examination) were invited to participate. Only women who were  S .  mansoni  egg-positive and  S .  haematobium  egg-negative were invited for gynaecological examination.  Fig 2  provides an overview of the participant recruitment process.\na Males, children, outside age range.  b Cervix, fornices, lateral, anterior and/or posterior vaginal walls.\nStool and urine samples from three consecutive days were collected at the health facility, transported to the KEMRI laboratory and investigated microscopically for  S .  mansoni  and  S .  haematobium  eggs. Two Kato-Katz smears were prepared from each stool sample and read by trained microscopists. Eggs were enumerated to determine eggs per gram of faeces (epg) and the presence or absence of the STHs ( Ascaris lumbricoides ,  Trichuris trichiura , hookworm) was noted. Intensity of infection for schistosomiasis was calculated based on arithmetic mean egg counts and categorized according to the WHO classification as negative for no detectable eggs; light  S .  mansoni  infection for 1–99 epg; moderate for 100–399 epg and ≥400 epg for heavy [ 40 ]. Urine samples were thoroughly mixed and a 10 ml aliquot of urine filtered through 12 micrometres, 13 millimetres Polycarbonate (PCTE) membrane filters (Sterlitech; Kent, WA). The filter paper was then placed on a labelled slide and a drop of Lugol’s solution added. The slides were then examined under a microscope for  S .  haematobium  and  S .  mansoni  eggs [ 40 ].\nA questionnaire on water contact behaviour, reproductive history, water sources, water exposure, genital and abdominal symptoms was administered individually to  S .  mansoni  egg-positive/ S .  haematobium  egg-negative participants in the local language (Dholuo) prior to gynaecological examination. The clinician performing the exams was blinded to the childhood origin of the women and the intensity of  S .  mansoni  infection. Examination was commenced by cervico-vaginal lavage. Saline (10 ml) was sprayed on the vaginal wall and cervix twice, whereupon it was drawn back into a syringe and deposited into four tubes. This was followed by photocolposcopic examination (Leisegang Photocolposcope, Germany, Magnifications 7.5; 15; 30) using an autoclaved metal speculum after which Pap (Papanicolau) smears were collected from all consenting women [ 41 ]. The cervix, the fornices, the entire vaginal wall and vulval surfaces were inspected section by section according to a predefined protocol [ 41 ]. Acetic acid and/or iodine application for colposcopic examination was always done last. The grainy sandy patch diagnosis was defined as observing grains approximately 0.05 mm by 0.2 mm long, shaped as minuscule rice grains, appearing singly or in clusters of up to 300 grains [ 42 ]. The homogeneous yellow patches were defined as sandy looking areas with no visible grains when using the x15 magnification setting on the colposcope. Rubbery papules were defined as papulous lesions, firm as hard rubber, that had only been seen in Madagascan women by the same clinician who had previously investigated women for FGS in four Southern African countries [ 43 ]. Abnormal blood vessels were defined as pathological convoluted (cork-screw), reticular, circular and/ or branched, uneven-calibre blood vessels visible (by x15 magnification) on the mucosal surface. Contact bleeding was defined as fresh blood originating from the mucosal surface. Pre-contact bleeding was defined as darkened blood on the mucosal surface in the absence of recent or present menstruation. A polyp was defined as a single, smooth pedunculated mass originating from the endocervix or from the mucosal surface. Leucoplakia was defined as white plaque on the mucosal surface, visible with or without acetic acid. Papilloma was defined as a sessile mass either on the mucosa or vulva, whitish in colour, often with a cauliflower appearance.\nData were entered into Excel, and analysed using SPSS version 12 and Graphpad Prism 5. Prevalence of  S .  mansoni  and soil-transmitted helminths are presented for all who underwent gynaecological examination.  S .  mansoni  data is also presented for those who submitted stool but did not attend the research clinic. Univariate and multivariate analyses were used to determine associations between the clinical manifestations and the intensity of  S .  mansoni  infection. P values < 0.05 were considered statistically significant.\n\nOut of the 773 women who provided stool samples, 414 (53.6%) had  S .  mansoni  infection with a mean intensity of 185 epg (95%CI: 155–216 epg). A total of 72 women from Kisumu West and 79 from Rachuonyo North sub-counties came for gynaecological investigations. We included 147 women as 2 had recently delivered a baby and 2 had undergone hysterectomies. The mean age of menarche was 14 years (SD = 1.96).\nAmong the 147 women who underwent gynaecological examinations, the mean intensity of  S .  mansoni  infection was 253 epg (95% CI: 195–312 epg).  Table 1  shows that almost all these women had contact with Lake Victoria waters at least once per day, more than 90% lived less than 900 metres from the lake, and most used the lake as their main water source for domestic chores.  Table 2  shows that more than half of the included population had heavy or moderate infections. The prevalence of the soil-transmitted helminths was 4.5% (95%CI: 3.3–6.3) for  T .  trichiura , 2.2% (95%CI: 1.4–3.5) for  A .  lumbricoides , and 0.3% (95%CI: 0.01–1) for hookworm respectively. No  S .  mansoni  eggs were detected in the urine of any of the participants. None of the women had  Schistosoma  ova in their Pap smears.\na 95% Confidence Interval.\nb Arithmetic mean infection intensity of eggs found in stool.\nc All included for gynae examination were  S .  mansoni  positive\nHomogenous yellow patches were found in 12/147 (8.2%) of the study population. No participants were found to have grainy sandy patches or rubbery papules. The women with homogenous yellow patches were significantly older than the remaining population (OR 1.1, 95% CI: 1.0–1.2, p = 0.001), mean age 47 years (SD 11.2) versus 34 years (SD 10.7). Homogenous yellow patches were not associated with the intensity of  S .  mansoni  infection (age-Adjusted Odds Ratio (AOR) 0.6, 95% CI: 0.1–6.7, p = 0.70) ( Fig 3 ). Likewise, having abnormal blood vessels on the mucosal surface (49/147, 33%), was not associated with the intensity of  S .  mansoni  infection (AOR 1.0, 95% CI: 1.0–1.0, p = 0.14). In 7 of the 147 women (4.8%), not all the surfaces of the fornices could be seen.\nNo significant association between symptoms and intensity of  S .  mansoni . *Likelihood ratio p-value.\nMore than half of the population had genital symptoms (58%).  S .  mansoni  intensity was not associated with higher prevalence of abnormal vaginal discharge (AOR 0.8, 95% CI: 0.1–6.7, p = 0.81), bloody discharge (AOR 0.2, 95% CI: 0.1–0.8, p = 0.21), or genital itch (AOR 0.8, 95% CI: 0.2–3.2, p = 0.79), as shown in  Fig 3 . Homogenous yellow patches (n = 12) were not associated with any of the symptoms (p >0.39).\nIn a selection of 140 women who were fully investigated gynecologically (all surfaces seen), 16 (11.4%) said they had grown up “far away” from Lake Victoria, although the exact distance could not be determined. They also indicated that they used other water sources in their childhood, such as rivers. These women had significantly more homogenous yellow patches (OR 5.6, 95% CI 1.4–21.8, p = 0.014). The age-adjusted odds ratio (AOR) was 3.9 (95% CI: 0.92–16.9, p = 0.065). Childhood residence or river contact did not influence the presence of abnormal blood vessels (p > 0.8).\n\nIn an area highly endemic for  Schistosoma mansoni , we found that  S .  mansoni  infection was not associated with any of the FGS lesions [ 18 ]. To our knowledge, this is the first study in women with  S .  mansoni  where the antero-posterior and lateral vaginal surfaces, fornices and cervix were all inspected by an FGS expert, using a colposcope [ 14 ]. We are therefore confident we would have detected FGS, if present. Underpinning this, there was no increase in bloody discharge, abnormal vaginal discharge or lesions with heavy intensity of  S .  mansoni  infection.\nPrevious studies have shown there is a strong association between  S .  haematobium  ova in urine or genitals and four different lesion types [ 18 , 41 ]. A small proportion of women were found to have homogenous yellow patches, however no grainy sandy patches or rubbery papules were seen in this  S .  mansoni  endemic area [ 42 ]. Although none of our patients had detectable  S .  haematobium  (in three urines) many reported to have had river contact “elsewhere” in their youth or childhood. Urine egg excretion is known to decrease with age and our study population may have ceased to excrete  S .  haematobium  ova [ 44 , 45 ]. Furthermore, in  S .  haematobium  endemic areas, it is worth noting that, even in the absence of excretion of ova in urine, 23–41% of women have one of the typical FGS lesions and ova in the genitals [ 41 , 46 ]. We cannot preclude that homogenous yellow patches are due to long-standing or prior  S .  haematobium  infection, they may be a sign of “aged” FGS lesions [ 47 ].\nThere is often a wide overlap in the geographic distribution of  S .  haematobium  and  S .  mansoni  in sub-Saharan Africa, making it difficult for single species incrimination [ 48 ]. In the absence of detectable ova in urine, other hard-to-achieve techniques such as species differentiation in histological specimens may be indicated or  S .  haematobium -specific PCR in cervicovaginal lavage or swabs [ 8 , 43 , 49 – 52 ]. While we did not observe any  S .  mansoni  eggs in urine, we cannot rule out the possibility that homogenous yellow patches may have been induced by a tendency of schistosomes to shift their intravascular positions late in chronic infection as occurs with liver fibrosis when stool ova excretion may be low or there may be abnormal migration patterns of adult worms triggered by “worm crowding” [ 7 , 53 – 55 ]. In this population, however, nothing was found to indicate genital deposition  S .  mansoni ova and ensuing inflammation on the cervico-vaginal or vulval surfaces.\nThere is an increasing interest in the gender-specific manifestations of urogenital schistosomiasis with a growing appreciation of its multiple nexus as a chronic risk for HIV transmission.  S .  mansoni  has been found in surgical specimens in Puerto Rico by Arean and others in the Fallopian tubes (18 cases), ovaries (10 cases); uterus or vulva (1 case), cervix (6 cases), and other case reports have also shown this [ 10 , 56 – 62 ]. However, most of these cases of  S .  mansoni  were incidental findings in conjunction with malignancies, cervicitis or teratoma. In the cases with cervicitis differential diagnostic tests were not performed and hence  S .  mansoni  cannot be ruled out as a cause.\nFGS is a neglected disease and has previously been overlooked as a sexual and reproductive health rights issue [ 63 , 64 ], including its possible link with cervical cancer, HIV, and also mental health and social consequences [ 65 , 66 ].  S .  haematobium  infection is associated with abnormal vaginal discharge and bloody discharge, indicating intravaginal lesions or inflammation [ 13 , 21 , 67 ]. While  S .  mansoni  ova can also be found in the genital tract, no study, including this one, has shown surface lesions of the intravaginal mucosa caused by  S .  mansoni . This study did not include  S .  mansoni  negative women and we did not perform analyses for other diseases such as sexually transmitted diseases or endometriosis. However, the lack of increased number or extent of cervicovaginal lesions and symptoms in women with heavy intensity  S .  mansoni  infections suggests that symptoms and findings were independent of  S .  mansoni . Furthermore, the same colposcope and colposcopist (EFK) that conducted the exams in this  S .  mansoni -endemic area had performed investigations and found ample FGS in four  S .  haematobium  endemic countries prior to this study [ 68 ]. Thus, we feel confident that, had lower genital tract lesions been present, caused by  S .  mansoni , we would have detected them.\nIn the upper genital tract, reports from pathology laboratories in  S .  mansoni -endemic areas have, on occasion, found  S .  mansoni  ova and we cannot preclude that our study participants may have been affected there [ 58 , 62 ]. Surgeries and laparoscopies cannot be done (for ethical reasons) as a research project, however upper genital tract should be explored when laparoscopy or surgery is done for other reasons. Alternatively, lesions of the upper genital tract can be explored in connection with post-mortems.\n\nIn this study population we found that  S .  mansoni  was not associated with lower genital tract lesions or genital symptoms. However, further investigations are needed to explore the causes of genital symptoms around Lake Victoria to offer correct management. Furthermore, the possibility of lesions and pathology due to  S .  mansoni  in the upper genital tract should be explored.\n\n(XLSX)\nClick here for additional data file.","source_license":"CC-BY-4.0","license_restricted":false}