Female genital schistosomiasis due to Schistosoma haematobium. Clinical and parasitological findings in women in rural Malawi

A national survey of the prevalence of schistosomiasis and soil transmitted helminths in Malawi

Background

Past estimates have put the prevalence of schistosomiasis between 40% and 50% in the Malawi population overall based on studies undertaken ten years or more ago. More recent surveys in known high risk areas find similar levels. However control measures, changing ecology and migration may have led to changes in the prevalence of schistosomiasis in different parts of Malawi. A national schistosomiasis and soil-transmitted helminth (STH) survey was undertaken to measure the distribution, prevalence and intensity of infection in November 2002.

Methods

A school was selected randomly from a random sample of 30 Traditional Authorities stratified by six distinct ecological zones, and 1,664 year 3 pupils (9–10 year olds) were questioned about recent illnesses and "red urine". Samples of urine and faeces were examined for the presence of eggs using the standard Kato-Katz technique for soil-transmitted helminths and intestinal schistosomiasis and urine samples using the filtration technique for Schistosoma haematobium.

Results

The prevalence of Schistosoma mansoni is 0.4% (95% CI 0–1.3%), S. haematobium 6.9% (95% CI 1.9 – 11.9%), hookworm 1.3% (95% CI 0.4–2.3%), Ascariasis 0.5% (95% CI 0.1–1.0%) and trichuriasis 0% in year 3 pupils (modal age 10 years of age). Intensity of infection is low for all infections except for 2.5% who have high intensity S. haematobium infection. The "red urine" question is 67% sensitive and 80% specific for positive S. haematobium microscopy.

Conclusions

The reduction in prevalences may be real as a result of recent control measures, or false if historical results were based on surveys of high risk populations. Another explanation is that this survey used an unrepresentative sample of schools. Detailed analysis suggests this is unlikely.

Recommendations include the use of a 30% positive threshold for the "red urine" screening question to be used in schoolchildren in high prevalence areas.

This survey, based on a national probability sample excluding the northern region lakeside area, finds much lower overall prevalence and intensity of schistosomiasis and STHs than previous estimates based on selected surveys. Disease control featuring chemotherapy may be having a profound effect. The localised nature of the distribution of the infections means that control programmes may work best if undertaken at district level or below. "Red urine" questionnaire surveys may help identify hot spots.

Female Genital Schistosomiasis: Case Report and Review of the Literature

A 37-year-old woman, originally from South Africa, presented for a gynecologic examination. Speculum examination revealed a friable cervical lesion. Both the cervical smear and biopsy contained intact, viable schistosome eggs consistent with those of Schistosoma haematobium. Appropriate treatment was initiated promptly, avoiding significant morbidity. The diagnosis of female genital schistosomiasis must be considered when the patient has a history of travel to or residence in endemic areas.

Assessment of eosinophil cationic protein as a possible diagnostic marker for female genital schistosomiasis in women living in a Schistosoma haematobium endemic area

Eosinophil cationic protein (ECP) levels were measured in vaginal lavage extracts from 518 Zimbabwean reproductive women, age range 15-49 years, to assess the potential use of ECP as a diagnostic marker for female genital schistosomiasis (FGS). One hundred and fifty women had confirmed FGS status. These included 77 (cases) women who had ova in genital tissue and 73 (controls) women who had no ova in genital tissue. Participants were examined at baseline, 3 and 15 months post-treatment with praziquantel. ECP levels were determined using the enzyme linked immunosorbent assay (ECP-ELISA). ECP levels from 18 Norwegian women were used to calculate the diagnostic values of the test. FGS was diagnosed from the study population using genital biopsy and smears. Women were also diagnosed for urinary schistosomiasis using the urine filtration technique. The prevalence of urinary schistosomiasis was 39 % at baseline and this declined to 8% and 6% at 3 and 15 month post-treatment surveys, respectively. There was a higher mean ECP level in women with FGS, 889.3 ng/mL (95% CI: 457.0-1327.5) compared to the endemic control group, 359.1 ng/mL (95%, CI: 227.3-490.9), P = 0.027. Mean ECP levels declined at 3 months following treatment of infected individuals. There was no correlation between ECP levels and tissue ova density, and urine egg intensity. The sensitivity, specificity, positive and negative predictive values for the ECP-ELISA test were 35%, 80%, 65% and 53%, respectively. Our results indicate that FGS causes an inflammatory immune response that increases ECP levels in genital fluid. Treatment of schistosomiasis results in a regression of pathology and a decline in ECP levels. However, other factors such as allergy and microbial infection could also be responsible for increased ECP levels in genital mucosa. These conditions will affect the validity of the test in diagnosis of FGS.

Endemicity of vesical schistosomiasis in the Ebonyi Benue river valley, south eastern Nigeria

The investigation on the prevalence of patent and clinically severe infections with Schistosoma haematobium was carried out amongst inhabitants of Ebonyi Benue river valley, South Eastern Nigeria between August 2000 and June 2001. The inhabitants are predominantly farmers. Of the 3296 subjects examined from 15 randomly selected villages in the valley, 776 (23.5%) were excreting the eggs of S. haematobium in their urine. Infection rates varied between 18.9% and 30.6%. The severity of infection calculated by arithmetic mean egg counts (AMEC) and geometric mean egg counts (GMEC) varied significantly between the age groups and the villages (P < 0.05). The prevalence and severity of infection increased with age from 0 to 25 years and decreased thereafter. Symptoms associated with the disease include visible hematuria (63.1%), suprapubic pain (10.3%) and stranguary (9.9%). While 65 positive persons had more than one symptom, 64 of the positive persons had no noticeable symptoms. Visible hematuria showed moderate sensitivity and high specificity for the disease. Female genital schistosomiasis (FGS) of the lower reproductive tract was recorded in 19 females of child bearing age that complained of severe suprapubic pain. Eight snail species were recorded in the stagnant ponds and both Bulinus globosus and B. truncatus were infected with schistosome cercariae. The factors contributing to these observations and feasible control measures are discussed.

Schistosomiasis of the uterus in a patient with dysmenorrhoea and menorrhagia

Abdominal hysterectomy was performed in a patient because of complaints of dysmenorrhoea and menorrhagia and the uterus was sent for histopathological analysis. Besides adenomyosis an extensive granulomatous infection with Schistosoma mansoni eggs was found.

The laparoscopic appearance of Schistosomiasis may be mistaken for "non-pigmented" endometriosis

The authors report the case history of a patient with symptoms and signs suggestive of endometriosis, who was found to have Schistosomiasis. The laparoscopic appearance was of gelatinous deposits throughout the pelvis which were thought to be "non-pigmented" endometriosis. However, histological examination of the biopsy specimens revealed Schistosomiasis.

Cervical schistosomiasis

We present a case history of a woman who was diagnosed as having cervical schistosomiasis on histology following investigations for abnormal cervical smear. Schistosomiasis of the female genital tract can present with varied symptoms and there is a need for greater awareness of this diagnosis as the number of travellers to schistosomiasis-endemic areas rises. Travellers to these areas should be warned about the risk of swimming in lakes and rivers.

Female genital schistosomiasis: facts and hypotheses

In this paper we summarise the parasitological, clinical and epidemiological characteristics of female genital schistosomiasis (FGS), a frequent manifestation of the infection with Schistosoma haematobium. Means to diagnose and treat lesions in the lower and upper genital tract are discussed. Based on clinical findings and available pathophysiological as well as immunological data it is conceivable that FGS of the cervix and vagina not only facilitates the infection with agents of sexually transmitted diseases, but presumably also alters the natural history of such infections. Two infectious agents are of particular concern: the Human Immunodeficiency Virus and the oncogenic Human Papilloma Viruses. Possible interactions and their consequences are discussed and research areas which should be addressed are outlined.

Assessment of morbidity in Schistosoma haematobium infection: current methods and future tools

Recently, new potential tools for assessment of Schistosoma haematobium related morbidity have emerged. The tools are based on detection of S. haematobium egg antigens in urine or detection of eosinophil cationic protein (ECP) in urine, which may reflect the inflammatory response in the urinary tract. So far two markers have been assessed in long-term post treatment follow-up studies, allowing for an evaluation both before treatment and during regression and reappearance of infection and urinary tract morbidity. The results from these studies and the usefulness of the markers as morbidity assessment tools are discussed.

Schistosomiasis of the female genital tract: public health aspects

In this paper Gabriele Poggensee, Hermann Feldmeier and Ingela Krantz discuss the public health relevance of female genital schistosomiasis (FGS). Some of the stated hypotheses are supported only by clinical observations and/or circumstantial evidence as valid epidemiological and immunological data of this disease entity are still very scanty. Morbidity caused by the presence of schistosome eggs in the lower and upper genital tract have been almost completely neglected during the past two decades. This has been acknowledged by the WHO and, in 1997, the Gender Task Force of the WHO's Tropical Disease Research Programme (TDR) included FGS in a list of scientific areas that deserve high research priority.

Genital manifestations of schistosomiasis mansoni in women: important but neglected

Egg-induced lesions in the upper and the lower female reproductive tract are important complications of the infection with Schistosoma mansoni. The understanding of the pathophysiology and pathology of genital lesions is only rudimentary, simple and reliable diagnostic tools are not at hand, epidemiological data do not exist and how to treat best the women affected, is not known. In view of recent advances in the understanding of genital lesions induced by S. haematobium the existing literature is critically analyzed and possible consequences of female genital schistosomiasis are outlined. We estimate that 6 to 27% girls and women with intestinal schistosomiasis, at least temporarily, suffer from pathology induced by eggs sequestered somewhere in their genital organs. This is a matter of concern and warrants more research into the epidemiology, pathology, diagnosis and therapy of this disease entity.

Clinical findings in female genital schistosomiasis in Madagascar

To assess the morbidity of S. haematobium infection in women of reproductive age (15-49 years) in the western part of Madagascar, the village of Betalatala with a prevalence of urinary schistosomiasis in women of 75.6% (95% confidence limit 69.3 to 81.9%) was compared with a neighbouring village with similar socio-economic characteristics and a prevalence of 5.0% (95% confidence limit 0 to 11.75%). The women were questioned in Malagasy about obstetrical history and urogynecological symptoms. They were examined gynaecologically, parasitologically and by ultrasonography. Important STDs were excluded by appropriate diagnostics. In Betalatala significantly more women reported a history of spontaneous abortion (P < 0.01), complaints of irregular menstruation (P < 0.001), pelvic pain (<0.05), vaginal discharge (P < 0.0001), dysuria (P < 0.05) and haematuria (P < 0.01) than in the control village. Biopsies were obtained from the cervix of 36 women with macroscopical lesions, and in 12 cases S. haematobium eggs were found by histological sectioning (33.3%). In the control village no eggs were detected in the histological sections of biopsies taken from 14 women. (P < 0.05). Infections with Candida albicans, Trichomonas vaginalis, Gardnerella vaginalis and Treponema pallidum were found in similar frequencies in both villages. In 9.8% of the women in Betalatala abnormalities of the upper reproductive tract were revealed by ultrasonography versus none in the women from the control village (P < 0.05). Echographic abnormalities of the urinary tract were present in 24% and 3% of the women in the study village and in the control village, respectively (P < 0.0001). These findings were accompanied by an elevated frequency of haematuria (55% versus 20%) and proteinuria (70.4% versus 25%) in the study population (P < 0.0001). Our study indicates that S. haematobium infection in women may not only cause symptoms in the urinary tract, but also frequently in the lower and upper reproductive tract.

Schistosoma haematobium induced lesions in the female genital tract in a village in Madagascar

Female genital schistosomiasis, FGS, was investigated in a gynaecological study as part of an overall community based morbidity survey, including parasitological and ultrasonographical examination, of a Schistosoma haematobium endemic area in Madagascar. Women (103), of childbearing age (15-49 years), were included for a gynaecological examination and visible lesions of vagina and cervix were biopsied in order to determine the origin of the lesion. Furthermore all women were screened for the presence of schistosome ova using PAP smears from the vagina and the endo/exo cervix. In total 15 women showed schistosome ova in the vagina and/or cervix (median age 24 years and range 15-36 years). Of 36 women with cervical abnormalities, 12 eggs were detected by cervical biopsy (33%). In addition, two of the 12 presented vaginal induration, which contained eggs. Six women had eggs in their PAP smears of which three were egg negative by cervical biopsy. The prevalence of positive S. haematobium egg excretion in the urine among the 103 women was 69% and the geometric mean egg count of positive individuals was 51 eggs/10 ml of urine. Five of the 15 women with confirmed FGS had < or = 1 egg/10 ml of urine. Bladder lesions and congestive changes in the kidneys were demonstrated by ultrasonographic examination in 33 and 9% of the 103 women, respectively. None of the 15 women with confirmed FGS had renal congestion. Our study demonstrates that FGS is a common manifestation of the infection with S. haematobium, even in lightly infected individuals.

Urine reagent strips for diagnosis of schistosomiasis haematobium in women of fertile age

Hematuria, proteinuria and leukocyturia were semiquantitatively assessed by reagent strips in single morning urine of women of fertile age visiting the outpatient department of the Mangochi district hospital, Malawi. This was part of a diagnostic approach to female genital schistosomiasis (FGS). In 51 women ova of Schistosoma haematobium were detected in urine by a filtration technique. In 33 of these women ova were also present in genital tissue as demonstrated by microscopic examination of biopsies. In 209 women no ova were found in the single urine filtered. There were significantly higher scores for hematuria, proteinuria and leukocyturia as well as of the combined reagent strip index (RSI) in egg-excreting than in egg-negative women. The sensitivity of a single hematuria, proteinuria and leukocyturia reading was 98, 84 and 73%, respectively. However, the respective specificity was only 24, 22 and 23%. The best prediction of urinary schistosomiasis was achieved by a +2 score for hematuria, of which the sensitivity was 94% and the specificity was 61%. The high false-positive rates can probably be explained by contamination of urine by vaginal secretion. Moreover, cases of schistosomiasis have probably been overlooked because only a single morning urine sample was examined. The total absence of hematuria, proteinuria and leukocyturia, however, may be used to rule out heavy infections in community surveys. There was no difference in reagent strip scores between women with genital and urinary schistosomiasis as compared with those with urinary tract lesions alone. Thus urine analysis reagent strip readings do not help to discriminate between S. haematobium infected women with and without FGS.

Reversibility of lower reproductive tract abnormalities in women with Schistosoma haematobium infection after treatment with praziquantel--an interim report

Little is known whether and to what extent antiparasitic treatment cures female genital schistosomiasis (FGS). Using a standard protocol, of twenty-one women with FGS nine were re-examined at two to nine weeks after they had been treated with praziquantel at a single dose of 40 mg/kg. Symptoms related to pathology of the urinary tract and to a lesser extent of genital pathology subsided in most patients. Schistosoma haematobium ova were no longer detectable in urine of any of the patients post-treatment. Efficiency of chemotherapy against adult worms was confirmed by the disappearance of circulating anodic antigen (CAA) in serum. Sandy patches showed resolution in two of four cases after chemotherapy. Papillomata due to schistosomiasis alone improved, but persisted in mixed infection with human papilloma virus (HPV) or when HPV was the only underlying cause. In one patient ulcera could not be related with certainty to schistosomiasis at admission, but resolved after treatment with parziquantel. Leukoplakia (two cases) was not influenced by chemotherapy, or even increased during follow-up, regardless of whether ova had been detected or not. Although the follow-up period was rather short, time intervals were not standardized, and a relatively small number of patients was investigated, it could be shown that genital pathology due to sequestered S. haematobium ova is, at least partially, reversible already two to nine weeks after killing the adult worms by praziquantel. This is paralleled by a normalization of inflammatory immune responses detectable in histological sections and vaginal lavage.

Female genital schistosomiasis (FGS): relationship between gynecological and histopathological findings

Schistosomiasis of the lower female reproductive tract manifests itself in a broad spectrum of clinical features. However, clinical and histopathological findings have never been studied in a synoptic manner. Based on the assumption that any type of pathology present in the female reproductive tract is the expression of a complex pathophysiological reaction towards eggs sequestered in the genital tissues, we decided to analyze colposcopic and histopathological findings in a comprehensive manner. Thirty-three women in Malawi with urinary and genital schistosomiasis were examined parasitologically and gynecologically. A thorough colposcopic examination with photodocumentation was performed and biopsies were taken from the cervix, the vagina and/or the vulva for histological sectioning and immunohistochemistry. The predominant colposcopic findings were sandy patches on the cervical surface similar to those seen in the bladder and polypous/papillomatous tumors with irregular surface on the vaginal wall and in the vulvar area. The histopathological sections of sandy-patch-like lesions demonstrated only a small cellular reaction around S. haematobium eggs in various stages of disintegration. In contrast, in the case of polyps the histology revealed a more pronounced immunological reaction characterized by a heavy cellular infiltrate. One case of invasive squamous cell carcinoma of the cervix was diagnosed. We conclude that colposcopy is a useful tool in the detection of FGS related pathology in the lower female reproductive tract and that the synoptic assessment of surface and of corresponding histological sections helped to understand the pathophysiology of S. haematobium associated disease in genital tissue.

Diagnosis of female genital schistosomiasis by indirect disease markers: determination of eosinophil cationic protein, neopterin and IgA in vaginal fluid and swab eluates

Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54 Malawi adolescent girls and women infected with S. haematobium. These women received a careful gynecological examination during which biopsies were taken from the cervix, and, if present, also from suspicious lesions in the vagina and the vulva. If the biopsies, either in wet crushed preparations or in histological sections, contained eggs the patients were considered to have female genital schistosomiasis (FGS; n = 33). The remainder (n = 21) were classified as having urinary schistosomiasis only. Eosinophil cationic protein (ECP), a cytotoxic granule protein of eosinophils, neopterin, a second messenger molecule generated during the activation of macrophages, and IgA as an indicator of local B-cell activation were quantitatively determined in vaginal fluid. To clarify the origin of ECP, this protein was also looked for in histological sections by an immunohistochemical method. In order to explore whether such disease markers can be detected after absorption to a tampon-like material, ECP and IgA were also assessed after elution from a non-porous, polypropylene fibre web impregnated with vaginal fluid. The concentration of ECP in vaginal fluid and the degree of immunohistochemical staining in histological sections were significantly higher in patients with FGS than in women with urinary schistosomiasis only. The amount of ECP detected in histological sections correlated to the number of eggs/mm2 of compressed genital tissue (rho = 0.36, P = 0.02), and the concentration of ECP in vaginal fluid correlated to the concentration of neopterin as well as to that of IgA (rho = 0.52, P = 0.004 and rho = 0.37, P = 0.02, respectively). Median neopterin concentration in vaginal fluid was also higher in the FGS group, but the difference was not statistically significant. ECP could also be detected in eluates from impregnated fibre webs, but the concentration was approximately one power of 10 less than in the original vaginal fluid. These results demonstrate that indicators of immunological mechanisms related to the egg-granuloma might be useful as indirect disease markers for women with FGS if assessed in vaginal washings or swab eluates.