Female genital schistosomiasis (FGS) in migrants - a systematic review of reported cases

Abstract

Background

Female genital schistosomiasis (FGS) is the manifestation of schistosomiasis in the lower and the upper reproductive organs. In endemic areas FGS is frequent with a tremendous impact on reproductive health. Anecdotal observations indicate that FGS also occurs in women emigrating from endemic areas who had moved to countries of the Global North. The objective of this study is to summarize existing knowledge on FGS in migrants with a focus on morbidity, diagnosis, and treatment.

Methods

For this systematic review, electronic medical databases including are PubMed/Medline, ScienceDirect and Google Scholar were searched for reports on FGS in migrants from January 1980 to October 2024. Additionally, literature not listed in PubMed such as Ph.D. thesis and other types of research documents not published in scientific journals was also investigated by looking into and by contacting scientists known to have worked on female genital schistosomiasis in the past.

Results

After screening, 35 cases of FGS in migrants were identified. The most common manifestation of FGS was at the Fallopian tubes (= 16), followed by the cervix (= 6), the ovaries, the uterus (each = 4), the breasts and the vulva (each = 2), and in one case in the vagina. In all cases the diagnosis was spurious.

Conclusions

This study shows that the manifestations of FGS in migrants are different from manifestations of FGS in travellers returning from endemic areas after holidays, and include life-threatening sequelae, such as extra-uterine pregnancy. Frequently, the diagnosis was established after years of suffering.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-026-04320-6.

Background

Genital schistosomiasis is a largely underestimated manifestation of schistosomiasis [1–3]. In women, community-based studies in sub-Saharan Africa have reported prevalence rates ranging from 8% to 37% [4–6]. Female genital schistosomiasis (FGS) of the lower reproductive tract includes vulval ulcerative, granulomatous and papillomatous lesions as well as “sandy patches” i.e. granulomatous patches in the vagina and cervix, as well as papules and neovascularisation in the mucosa of the cervix [7–11]. In the upper/inner genital organs presence of egg granulomata in the ovaries and/or the Fallopian tubes is associated with primary or secondary infertility. Obstruction of the Fallopian tubes may lead to ectopic pregnancy [2, 12].

FGS affects women across all age groups, including girls prior to sexual activity [1, 13, 14]. Due to the nonspecific nature of FGS lesions and their syndromic overlap with common sexually transmitted infections (STIs), such as genital itching, abnormal discharge, and contact bleeding, FGS may easily be mistaken for other conditions. Although HPV infection is typically asymptomatic and chronic HIV infection may also be clinically silent, FGS-related mucosal inflammation can act as a cofactor for cervical dysplasia and may increase susceptibility to coinfections. These overlaps may lead to misdiagnosis, potentially resulting in stigma and psychological stress [15].

While the majority of FGS cases are caused by Schistosoma (S.) haematobium, other species, such as S. mansoni, S. japonicum, and possibly hybrids with zoonotic species associated with intestinal and hepatosplenic schistosomiasis, have also been implicated as causative agents [16–19].

Each year, thousands of women of reproductive age migrate from regions where schistosomiasis is endemic to countries in the Global North, suggesting that a notable proportion may present with female genital schistosomiasis (FGS) upon arrival. To date, however, there have been no systematic studies investigating the prevalence or characteristics of FGS in migrant populations [20, 21]. This systematic review aims to consolidate current knowledge on FGS in migrant women and to highlight challenges associated with the diagnosis and management of this condition in non-endemic setting.

Methods

This systematic review was guided by the standards of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines [22].

Search strategy

Online electronic databases such as PubMed/Medline, ScienceDirect and Google Scholar were individually searched using the terms female genital schistosomiasis AND migrant OR migration, as well as Schistosomiasis AND woman (OR female OR female genital schistosomiasis OR urogenital schistosomiasis) AND migrant OR migration. In addition, literature not listed in PubMed such as Ph.D. thesis and other types of research documents not published in scientific journals was also investigated by looking into and by contacting scientists known to have worked on female genital schistosomiasis in the past. Further publications were identified via “snowball search”, i.e. citations in other publications were also consulted. There were no restrictions on publication language for the included studies. References from the included studies were hand-searched for publications with relevant information according to the objective of the study. The flow diagram is depicted in Fig. 1.

Fig. 1.

Flow diagram of the literature search

Inclusion criteria

Articles were eligible if published between 1980 to October 2024. Studies conducted before 1980 were not included due to the absence of relevant data that could contribute to our understanding of FGS in migrants.

Study selection

After duplicate removal, two researchers screened the titles and abstracts of the records following PRISMA guidelines. For final inclusion, the full text of each potentially relevant study was independently read and evaluated by both researchers. Any disagreements during the review process were resolved through additional discussion.

Data extraction

Two reviewers independently extracted data from the included studies using a Microsoft Excel spreadsheet. The data extraction sheet included the first author’s name, year of publication, study country, mean age and clinical symptoms. The majority of publications contained only descriptive data. Therefore, a narrative style was used to summarize the current knowledge.

Assessment of study quality

Quality assessment of the data was conducted using a five-item quality framework that evaluated the clarity of objectives, sample selection, population definition, methodological rigor, and data analysis. Each criterion was assigned a score of 1 (Yes) or 0 (No/Not available), resulting in a total score ranging from 0 to 5. Studies were classified as “poor,” “fair,” “good,” or “excellent” based on their summative scores, with only those rated “fair” or higher included in the final analysis.

Results

Demographic and migration characteristics

After screening, 35 cases of FGS in migrants were identified. 20 cases were reported before 2000, 15 from 2000 until 2024. Demographic characteristics of the patients are summarized in Table 1. Cases were reported from six European countries, the USA, Australia, and Brazil. Median age at diagnosis was 29.5 years (range 20–63). The most common manifestation of FGS was at the Fallopian tubes (= 16), followed by the cervix (= 6), the ovaries, the uterus (each = 4), the breasts and the vulva (each = 2), and in one case in the vagina. In all cases the diagnosis was spurious.

Table 1.

Demographic characteristics of patients with FGS (n = 35)

Country of origin (n)	Age (years)	Country where FGS was diagnosed (n)*
Africa (3)**	21, 32 and 41	France (9)
Angola (1)	24	USA (8)
Brazil (2)***	39 and 47	Germany (7)
Congo (1)	29	UK (4)
Gambia (1)	26	Brazil (2) **
Ghana (1)	22	Australia (2)
Guinea (1)	20	Spain (1)
Liberia (2)	22 and 63	Ireland (1)
Kenya (1)	23	not reported (1)
Mali (1)	29
Mauritania (1)	35
Nigeria (3)	26, 30 and 31
Puerto Rico (1)	30
Senegal (4)	21, 22, 27 and 33
Sierra Leone (1)	30
South Africa (1)	28
St. Lucia (1)	32
Tanzania (1)	N.A.
The Philippines (2)	35
Tunisia (1)	28
Zambia (2)	37 and 51
Zimbabwe (3)	20, 23 and 31

*For one case, the country where the diagnosis was established was not documented

**Country of origin not reported

***Patients had lived in rural S. mansoni endemic areas in West Brazil and had migrated to urban centres in Central and East Brazil many years before FGS was diagnosed

N.A. Non Applicable

Gynaecological manifestations

Vagina, vulva, and peri-anal area

A 23-year-old woman from Kenya reported persistent dysmenorrhea, the aetiology of which could not be identified. During a routine gynaecological examination, a suspicious area in the vagina led to a biopsy. The histological examination showed the presence of S. haematobium eggs in all layers of the vaginal wall [23].

A 26-year-old woman from Gambia consulted on her own initiative the Tropical Disease Service in Germany for leaking of urine from the vagina [24]. Her treating gynaecologist had not considered to send her to a Tropical Disease clinic. During the urological examination and contrast CT, a vesico-vaginal fistula was identified. A biopsy from the rim of the fistula showed S. haematobium eggs located within multiple granulomata. No eggs were excreted in urine and no bladder abnormalities were detected. The patient was treated with 3 courses at 40 mg/kg praziquantel. The fistula was eventually closed surgically four months later. It healed completely with no more leaking of urine during follow-up [24].

A 22- year-old patient from Liberia consulted a gynaecological clinic for secondary infertility. During routine examination, a fistula between vulva and anus was seen. The histological examination of a biopsy from the rim of the fistula showed many S. haematobium eggs. Eggs were also identified in a routinely taken PAP smear [25]. How the patient was treated was not reported.

Cervix

In six migrants from different African countries routine colposcopy showed pathological alterations suspicious for Human Papilloma Virus (HPV) infection. PAP smears were taken and examined cytologically. In all cases, eggs of S. haematobium were identified [26–29]. The cytological alterations were graded High-Grade Squamous Intraepithelial Lesion (HSIL) in one and Low Grade Squamous Intraepithelial Lesion (LSIL) in another case. In one patient, a biopsy was taken from a suspicious lesion at the cervix. The presence of eggs in all layers of the epithelium was confirmed by histology. Both patients were treated with praziquantel (dose not reported).

Additionally, for the patient with HSIL, HPV testing was performed as part of the PAP smear evaluation, and follow-up PAP smears showed complete resolution of HSIL, with no eggs detected in subsequent tests [28]. However, the initial HPV testing result was not explicitly reported as positive or negative. In contrast, for the patient with LSIL, HPV testing results were not reported, and no follow-up information is available regarding her condition. Furthermore, no HPV testing was conducted for the remaining cases.

Fallopian tubes and/or ovaries

In 18 migrant women FGS of the Fallopian tubes was diagnosed. In ten patients acute abdominal pain had led to hospitalization (Table 2) [23, 30–37]. Presumed diagnosis was adnexitis (2), extrauterine pregnancy (4), cancer of Fallopian tube (1), cancer of ovary (2), ovarian cyst (1). In all cases, the correct diagnosis was established by histological examination of biopsies taken during laparoscopy or laparotomy. In one patient, the histology showed miracidia hatching from eggs, an indicator that the eggs had been deposited by a female worm recently [36].

Table 2.

FGS at fallopian tubes and/or ovaries presenting with acute abdominal pain (n = 10)

Age	Country of origin	Symptoms + signs	Presumed diagnosis	Gynaecological findings	Diagnosis	Remarks	Authors
30	Nigeria	Acute abdominal pain	Adnexitis	Dilatation of both tubes; Tumour right ovary; Tumour right Fallopian tube	Laparotomy; histology: Eggs of S. haematobium	Tubal occlusion already documented 2 years before	[37]
24	Angola	Acute abdominal pain	Extrauterine pregnancy	Dilatation distal part of both tubes; adhesions of tubes to peritoneum; hemoperitoneum	Laparoscopy; histology: Eggs of S. haematobium	Rubbery papules on parietal peritoneum	[34]
22	Ghana	Acute abdominal pain	Extrauterine pregnancy	Nodules on both Fallopian tubes	Laparoscopy; histology: Eggs of S. haematobium	Tumor in bladder wall; eggs in urine	[23]
31	Nigeria	Acute abdominal pain	Extrauterine pregnancy		Laparoscopy; histology: Eggs of S. haematobium in tubal wall		[32]
51	Zambia	Acute iliac fossa pain	Tubo-ovarian abscess; cancer of Fallopian tube	Tumor right Fallopian tube	Laparotomy; histology: Eggs of S. haematobium inside tumor	Grade 3 serous carcinoma	[30]
37	Zambia	Acute abdominal pain	Extrauterine pregnancy	Grainy sandy patches left Fallopian tube	Histology: Eggs of S. haematobium	One year later identical findings at right Fallopian tube	[35]
39	Brazil	Acute abdominal pain	Carcinoma of ovar	Large abdominal mass	Laparotomy: cystadenocarcinoma; S. mansoni eggs inside tumor		[33]
47	Brazil	Acute abdominal pain	Carcinoma of ovar	Large abdominal mass	Laparotomy: papillary serous carcinoma; S. mansoni eggs inside tumor		[33]
29	Mali	Acute abdominal pain	Ectopic pregnancy	Hydrosalpinx left + right; prolapse of left Fallopian tube into Douglas space	Laparoscopy; histology: S. haematobium eggs		[31]
32	St. Lucia	Acute abdominal pain	Ovarian cyst	Firm tender mass in right adnexal region attached to uterus and peritoneum; Right Fallopian tube enlarged and dilatated	Laparotomy; histology: multiple S. mansoni eggs granulomata in all layers of right tube; recently formed granulomata with miracidia; calcified eggs surrounded by fibrosis		[36]

Nine patients with FGS of the Fallopian tubes and/or ovaries sought gynaecological advice due to primary (n = 7) or secondary infertility (n = 2) (Table 3) [31, 38–43]. Presumptive diagnoses were tuberculosis, adnexitis, and ovarian cancer. Laparoscopy showed unilateral (n = 1) or bilateral (n = 8) hydrosalpinx with extended adhesions to ovaries, the sigma, or omentum majus. Histology revealed the presence of S. haematobium eggs in the excised tissue in all cases.

Table 3.

FGS at the fallopian tubes and/or ovaries presenting as infertility (n = 9)

Age	Country of origin	Symptoms + signs	Presumed diagnosis	Gynaecological findings	Operation/Diagnosis	Remarks	Authors
21	Africa*	Primary infertility	Tumor of ovary	Large tumor on top of left ovary	Oophorectomy; histology: S. haematobium eggs		[42]
26	Nigeria	Primary infertility	Adnexitis	Bilateral tubal occlusion	Salpingectomy; histology: S. haematobium eggs	Grainy sandy patches in vesico-uterine pouch; eggs in urine	[38]
29	Congo	Primary infertility	Not reported	Hydrosalpinx left + right; Grainy sandy patches on surface of Fallopian tubes and peritoneum; adherence of Fallopian tubes to ovaries	Salpingectomy; histology: S. haematobium eggs		[40]
35	Mauritania	Primary infertility	Not reported	Hydrosalpinx left + right; Adherence of tubes to surface of sigma	Hysterectomy; histology: S. haematobium eggs in muscle layer in both Fallopian tubes	Eggs in urine	[40]
21	Senegal	Primary infertility	Not reported	Hydrosalpinx left + right; nodules at surface of right Fallopian tube	Salpingectomy; histology: eggs S. haematobium		[40]
22	Senegal	Primary infertility	Tuberculosis	Hydrosalpinx left + right; nodules on omentum majus	laparoscopy, histology: multiple granulomata with calcified eggs		[31]
28	Tunisia	Primary infertility	Tuberculosis	Bilateral hydrosalpinx; adhesion of Fallopian tubes with ovaries	Histology: eggs in muscle layer of both tubes		[39]
33	Senegal	Secondary infertility	Not reported	Bilateral hydrosalpinx	Laparoscopy, histology: eggs in muscle layer of both tubes		[41]
27	Senegal	Secondary infertility	Adnexitis	Hydrosalpinx left + right; enlargement ovaries; tubes and ovaries form a single mass adhering to peritoneum	Salpingectomy; laparoscopy; histology: S. haematobium eggs		[43]

In three patients, descensus uteri, bloody vaginal discharge or haematuria/dysuria led to the gynaecological consultation [35, 44, 45]. In all cases, eggs were identified by histology in biopsied tissue.

In three patients, the presumptive diagnosis of extra-uterine pregnancy was confirmed and was caused by tubal occlusion/adhesions caused by clusters of S. haematobium eggs (Table 4)[32, 35, 36]. In two cases, an ovarian carcinoma was identified and in two cases carcinoma of a tube [30, 33, 37]. S. haematobium eggs were located inside the Fallopian tube carcinoma, and S. mansoni eggs in the carcinoma of ovaries .

Table 4.

FGS of the fallopian tubes presenting with various manifestations (n = 3)

Age	Country of origin	Symptoms + signs	Presumed diagnosis	Gynaecological findings	Diagnosis	Remarks	Authors
24	Angola	Descensus uterus	Tuberculosis	Not reported	Laparoscopy; histology: multiple S. haematobium egg granulomata in mucosal layer of Fallopian tubes		[45]
20	Zimbabwe	Haematuria, dysuria	Not reported	Fibrosis of Fallopian tubes	Hysterectomy; histology: S. haematobium eggs in fibrous tumor of Fallopian tube and uterus	11 years earlier salpingectomy due to ectopic pregnancy; FGS not considered	[44]
37	Zambia	Bloody vaginal discharge	Not reported	Grainy sandy patches left Fallopian tube	Laparoscopy, histology: S. haematobium eggs in Fallopian tube		[35]

Uterus

A 21-year-old woman from Sierra Leone presented in a gynaecological clinic in Germany for hypermenorrhoea. Laparoscopy showed a large transmural myoma with extended adhesions to the colon and the omentum magnus. Myomectomy was performed. The histological examination showed multiple S. haematobium egg granulomata inside the leiomyoma [46]. A 22-year-old woman from Tanzania consulted a gynaecological clinic in Australia complaining about persistent abdominal pain. Laparoscopy showed an enlarged uterus with a large whitish tumour. The histology showed a fibrous tumour with eggs of S. mansoni located inside the tumour. In a blood vessel inside the tumour schistosome worms were identified [44]. A 32-year-old patient from West Africa was seen in a gynaecological clinic in France reporting persistent leukorrhea. A curettage was performed. The histological examination showed that the endometrium was almost completely destroyed by a multitude of egg granulomata. Eggs were also seen in clusters in the musculature [47].

Breast

In two migrants from the Philippines, routine mammography showed microcalcifications suggestive of malignancy. In the biopsy, S. japonicum eggs were identified in calcified eggs granulomata [48, 49].

Treatment

In 16 patients, treatment with the anthelminthic drug praziquantel was documented. However, in the great majority of patients the dose was not noted, and follow-ups were either not done or not reported. In three patients, a therapeutic effect was documented. In a patient from Gambia with a vesico-vaginal fistula, the fistula was successfully closed surgically four months after three single dose courses of praziquantel at 40 mg/kg. At this point of time, schistosomiasis-associated bladder lesions had healed, and no more eggs were excreted in the urine [24]. In a 28-year-old patient with alterations at the cervix classified as HSIL, suspicious lesions at the cervix disappeared and PAP smears became normal in follow-ups after treatment with praziquantel [28].

In a 29-year-old patient with a dilatated left Fallopian tube and prolapse into the Douglas space six months after treatment with praziquantel, the Fallopian tube had regained its normal size and position [31].

Discussion

Although FGS has been known since 1899 [50], its importance for reproductive health was first acknowledged only 50 years later, in 1949 [51]. For several years, the public health importance of FGS in endemic countries is well established [20, 21, 52]. To the best of our knowledge, the manifestations of FGS in migrants have never been assessed systematically. Considering the high prevalence of schistosomiasis among migrants from endemic countries, mainly in Sub-Saharan Africa, and the fact that almost all reported cases were incidental findings, we must conclude that FGS is largely overlooked in non-endemic settings. More importantly, many women from endemic countries may have been misdiagnosed and subjected to unnecessary clinical, diagnostic, and therapeutic procedures, resulting in secondary harm (in addition to the missed diagnosis of FGS). The magnitude of this issue could be substantial: an estimated 11 million Sub-Saharan migrants currently live in Europe, and the prevalence of Schistosoma seropositivity among them is as high as 24% [53] reaching up to 35% in some reports [54]. In this regard, a major contributing factor is the lack of awareness of schistosomiasis among European clinicians and healthcare professionals [55].

In women living in endemic areas, as a result of constant re-infection, the worm load builds up over time, increasing the odds that a high number of worms is present in the vasculature of the lower and/or the upper reproductive organs [56]. Post-mortem and histological studies show that multiple topographic localizations of adult worms are the rule and that by consequence different reproductive organs are affected simultaneously or subsequently [57–60]. Irrespective of the anatomic structure of the genital organ affected, eggs may be present in all strata of the tissue. Schistosoma infection may persist for years or even decades, evolving into a chronic form, including chronic FGS, which can be even more difficult to diagnose definitively (direct detection of parasites or eggs is rare in long-lasting cases due fibrosis of the mucosae of the bladder resulting from chronic infection and to low-parasite-load). Therefore, FGS cannot be excluded even among long-term migrants or women beyond reproductive age (> 49 years). Furthermore, chronic FGS may have distinct clinical manifestations including infertility and vagino-vesical fistulae [24, 37, 61]. Duration of residence (years since migration) of the reported cases, as far as available, was for several years. Some of the cases were never referred to a tropical disease department and should specialized tropical diseases diagnostics upon their own initiative [23]. Gynecologists in the high-income countries must consider not only STD’s and genital tuberculosis but also FGS in the list of differential diagnosis, disregarding time since migration [55, 62].

This analysis shows that migrants with FGS present a broad spectrum of disease manifestations ranging from vesico-vaginal fistula, infertility to ectopic pregnancy. Actually, the spectrum of manifestations is very similar to that in women living in endemic areas, but differs from manifestations of FGS in travellers returning from holidays in endemic areas [63]. FGS of the uterus has been rarely seen in post-mortem and histology studies but was documented in three migrant patients [44, 46, 47]. The observation by Joyce et al. 1972 showed, for the first time, that the endometrium may be almost completely destroyed by egg granulomata [44].

Another unexpected finding was the observation in a migrant from the Philippines that S. japonicum (a worm species restricted to Southeast and East Asia) may cause lesions in the breast mimicking breast cancer. In contrast, vulval lesions present in 16/38 travellers with FGS were documented only in two migrants (unpublished observation). In three patients’ extra-uterine pregnancy had developed as a sequel of FGS. Ectopic pregnancy as a complication of FGS is known to be frequent in women living in endemic areas [35, 64, 65].

For long, infertility has been known to result from schistosomiasis of the ovaries and/or the Fallopian tubes. In endemic areas, primary and secondary infertility is considered the most common manifestation of FGS [37, 66–69]. However, whether infertility was caused by egg granulomata located inside the ovaries or in the wall of the Fallopian tubes or extended adhesions of these organs with each other, the sigma or the omentum majus was never ascertained because laparoscopy is seldomly performed in resource-poor settings typical for endemic areas.

It is noteworthy that in nine migrants with FGS, primary or secondary infertility was the cause for seeking gynaecological advice (Table 3). Reportedly, women had already been infertile for many years and had consulted various gynaecologists without FGS being considered as the aetiology. Laparoscopy showed that Fallopian tubes were enlarged, dilatated or occluded and showed extended adhesions to ovaries, omentum majus and colon. In all cases, eggs were identified in the affected organs by histology. In one patient, salpingitis seemed to be due to an acute inflammation triggered by viable eggs. As adult worms from time to time shift their anatomic localization within the plexus of the pelvis, acute pathology may develop at any internal or external genital organ, although the overall FGS-associated morbidity is of chronic nature [56]. Although HPV infection is typically asymptomatic and chronic HIV infection may also be clinically silent, FGS-related mucosal inflammation can act as a cofactor for cervical dysplasia and may increase susceptibility to coinfections. These overlaps may lead to misdiagnosis, potentially resulting in stigma and psychological stress [15].

Diagnosis

Genital involvement is generally underestimated as a manifestation of schistosomiasis even in endemic areas where up to 75% of women infected with S. haematobium may have genital involvement and up to 20% of women with genital involvement do not excrete schistosoma ova in urine [70], underscoring the magnitude of FGS-related morbidity [20, 21]. Hence, it is not surprising that in all cases the diagnosis of FGS was made accidentally as previous studies have indicated that FGS often goes undiagnosed due to the lack of awareness among healthcare providers about its manifestations, leading to accidental diagnoses during unrelated medical examinations or treatments [1].

The symptom most frequently reported by migrants was acute abdominal pain. Although not precisely stated in the case reports, these patients were probably considered as gynaecological emergencies, because extra-uterine pregnancy was named as presumptive diagnosis in most of the cases (Table 2). Other presumptive diagnoses were adnexitis (1), tubo-ovarian abscess (1), carcinoma of ovar (2), and ovarian cyst (1). Except for one case of carcinoma of the ovar and two cases of extra-uterine pregnancy, the presumptive diagnosis turned out to be wrong. In all cases, S. haematobium eggs were identified by the histopathologist in biopsies or in tissue obtained from surgically removed Fallopian tubes and/or ovaries [23, 30–37]. In none of the migrants FGS was considered as a differential diagnosis, even if characteristic lesion types, such as grainy sandy patches, homogenous sandy patches, or rubbery papules were observed during laparoscopy or laparotomy [23, 31, 34, 38, 40]. Considering all the awareness and diagnostic difficulties described above, a routine examination of migrants for tropical diseases from endemic countries should be implemented in all non-endemic countries as supported by a number of studies [53–55, 61, 62, 70]. This also contributes to prevent the introduction of an authochthonous life cycle in areas where Bulinus vector snails are endemic [71–75].

Treatment

There is uncertainty to which extent treatment with the anthelminthic drug praziquantel reverses FGS associated pathology [24, 76, 77]. A recent study from Zambia showed that after a single dose of praziquantel (40 mg/kg), clinical pathology resolved in 60% [78].

In one patient with cervical intraepithelial neoplasia, pathology present at the cervix completely disappeared after treatment with praziquantel, and repeated PAP smears showed absence of eggs [28]. Similar observations were made in travellers with FGS (unpublished observation). The observation that cervical intraepithelial neoplasia (CIN) resolves after antihelminthic treatment with praziquantel could reflect a cause-effect relationship between schistosomiasis at the cervix and the development of HPV-induced CIN, a hypothesis formulated long ago [79–81].

Conclusions

In conclusion, FGS in migrants, although well-documented, remains a neglected condition in women infected with schistosome worms, affecting all reproductive organs. Despite existing diagnostic clues for schistosomiasis of the reproductive organs, FGS was not initially considered a presumptive diagnosis in any of the migrant cases studied, leading to serendipitous true diagnoses. Notably, although outside the predefined review period, a recent case series of long-term migrant women in Europe corroborates our findings by documenting chronic FGS, characterized by persistent, non-specific gynecological symptoms and prolonged diagnostic delay, and underscores the need for clinicians to diagnose and manage the condition promptly to support affected women [82]. In conclusion, to address this oversight, FGS should be incorporated into diagnostic guidelines for female migrants who resided in schistosomiasis-endemic areas during adolescence and/or their reproductive years. Treatment with the anti-helminthic drug praziquantel is essential, but further research is needed to determine the optimal treatment regimen, such as single versus repeated doses, to effectively reverse lesions caused by schistosomiasis.

Abbreviations

FGS

Female genital schistosomiasis

HPV

Human Papilloma Virus

HIV

human immunodeficiency virus

HSIL

High Grade Squamous Intraepithelial Lesion

LSIL

Low Grade Squamous Intraepithelial Lesion

Authors’ contributions

JR, CDG and GHG: study concept and design, acquisition of data, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, administrative, technical or material support, approval of final version, and accountable for accuracy and integrity of the work.

Funding

The study was not supported by any funding.

Data availability

Not applicable.

Declarations

Ethics approval and consent to participate

Not applicable for this study. This article does not contain any studies with human participants or animals performed by any of the authors.

Consent for publication

Not applicable.

Competing interests

C.D.G. is employed by Ares Trading S.A., Switzerland, an affiliate of Merck KGaA. The other authors have stated explicitly that there are no conflicts of interest in connection with this article.