Female genital schistosomiasis: case report and review of the literature.

Abstract: 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.

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Female genital schistosomiasis (FGS) is a frequent complication in women with urinary or systemic schistosomiasis, particularly in geographic areas where the disease is endemic. Schistosoma haematobium is the organism most frequently identified in these cases. Persistent, untreated infections may lead to increased susceptibility to sexually transmitted diseases, or even sterility. We describe a case of FGS involving the uterine cervix.

Case Report

Two months after immigrating to the United States, a 38-year-old South African woman, gravida 5, para 5, presented for gynecologic examination to receive contraception. Her past medical and surgical history was unremarkable. Gynecologic history was significant for five uncomplicated spontaneous vaginal deliveries, and for receiving Depo-Provera injections 8 months earlier, in South Africa. Her physical examination was unremarkable, and she was afebrile. Pelvic examination was initially deferred secondary to heavy menstrual flow.

When seen in clinic 1 week later, pelvic examination revealed normal-appearing external genitalia, and an 8-week-size nontender uterus with unremarkable adnexal structures on bimanual examination. Speculum examination with direct visual inspection and subsequent colposcopy revealed a friable squamocolumnar junction from the 3 o'clock to the 9 o'clock positions. A cervical smear was performed, and a tissue biopsy was taken from the 6 o'clock position. Microscopic examination of the specimens revealed intact schistosome eggs, consistent with those of S. haematobium, along with inflammation in both the cytologic and histologic preparations (Figs. 1 and 2). Characteristic eggs could not be demonstrated in either the urine or stool specimens collected. On further questioning, the patient reported that while in Africa, she had walked barefoot through a rice field in the rain. The patient was then treated with oral praziquantel 1,200 mg bid for 1 day. She did not return for follow-up.

Discussion

Schistosomiasis is the infection of humans by trematodes (a class of helminths) belonging to the superfamily Schistosomatoidea. Three major species of schistosomes are pathogenic to humans: S. haematobium, Schistosoma japonicum, and Schistosoma mansoni. (1,2)

[FIGURE 1 OMITTED]

When eggs excreted from infected humans contaminate bodies of fresh water, they hatch to release free-swimming miracidia, which in turn infect snails, the intermediate hosts. The miracidia mature inside the snails to become cercariae, which are released back into the water, and can penetrate the water-softened skin of unsuspecting humans. Cercariae then mature into adult worms in the portal venous system. (1,2)

Depending on the species, schistosome adults migrate to various organ-specific venous plexuses: 1) urinary bladder for S. haematobium, 2) small intestine for S. japonicum, and 3) large intestine and rectum for S. mansoni. (1,2) Owing to the extensive anastomoses among the venous plexuses of the pelvic organs, S. haematobium (and to a lesser extent, S. mansoni) is the organism most often identified in FGS. (3-5) Although the 2- to 3-cm adult worms may cause venous obstruction where they reside, disease is more commonly caused by the daily deposition of numerous eggs by the female, which induces a localized host response and can lead to extensive tissue damage. (1,2) Live schistosome eggs excreted in the feces or the urine begin the life cycle again.

[FIGURE 2 OMITTED]

FGS poses a serious health risk to women of reproductive age living in endemic areas, particularly southern and western Africa. (4-7) Postmortem studies have documented histologic evidence of schistosome eggs in the genital tract in 3 to 100% of cases examined. (3,5) Previous studies have also shown that FGS is a common manifestation of S. haematobium infection, with a prevalence ranging from 30 to 75%. (5,7) It has been estimated that approximately 9 to 13 million women may be afflicted with FGS in Africa alone. (6) Another important patient population to consider is composed of women who have visited endemic areas (especially if they have swum in freshwater lakes), or those who previously resided in those endemic areas. (8) FGS may be an important risk factor in the spread of sexually transmitted diseases (including human immunodeficiency virus), and may lead to infertility secondary to ovarian fibrosis or tubal occlusion. (3-5,9) FGS may indeed be a cofactor for the development of cervical cancer, but a clear link has yet to be established. (4,5,10,11)

The clinical manifestations of FGS are nonspecific and can include irregular bleeding, discharge, pelvic pain or tenderness, dyspareunia, and otherwise unexplained infertility. (2,3-5,7,12,13) The signs and symptoms of chronically infected women may be minor or completely subclinical. (2) The majority of patients with FGS fall into the latter (ie, chronic) category.

The lesions most frequently encountered on pelvic examination and colposcopy are polypoid or papillomatous tumorlike lesions on the vaginal wall and vulva, and sandy patches on the cervical surface. (3,10,13) The sandy patches are similar to those encountered in cases of urinary schistosomiasis, and oftentimes concentric blood vessels are seen surrounding these lesions on colposcopic examination. (2,13)

Macroscopically, lesions in FGS may mimic any neoplastic or infectious process in the female genital tract. (3) Therefore, it is imperative to obtain material for confirmation of FGS by cytologic, histologic, or parasitologic methods.

The diagnosis of FGS is first suspected after taking a careful history and physical examination, making sure to consider travel history or residence in endemic areas. (8) Eggs can be directly visualized in urine via filtration and staining. However, this test has limited use in the diagnosis of FGS, because FGS may exist independently and without signs of urinary schistosomiasis. (6,7) Direct visualization of schistosome eggs is considered the gold standard. Microscopic examination is performed on fresh, crushed biopsies of the cervix or histologic sections of formalin-fixed tissue. (6,10) S. haematobium eggs are ovoid, average 150 [micro]m X 50 [micro]m in greatest dimensions, and have a delicate terminal spine (as opposed to the pronounced lateral spine of S. mansoni). (1) On histologic sectioning and subsequent hematoxylin and eosin staining, immature schistosome eggs have a basophilic internal structure, with distortion of the outer shell secondary to paraffin embedding. (2) The characteristic lesions seen in FGS correlate well with the histologic findings. The cervical sandy patches consist of a fibrous connective tissue reaction with a sparse, chronic inflammatory infiltrate, focused around eggs in various stages of disintegration. In contrast, the vulvar and vaginal polypoid or papillary lesions are composed of a more acute, florid inflammatory reaction to clusters of viable-appearing eggs. (10) Granulomata and eosinophils are often seen in the latter lesions. There is a direct correlation between genital lesion size and the number of eggs counted on fresh tissue biopsy. (13) Fixed, Papanicolaou-stained cervical smear preparations can also be used to visualize schistosome eggs. (13)

Immunodiagnostic techniques such as immunofluorescent antibody, enzyme-linked immunosorbent assay, or complement fixation have been used in reference laboratories to help establish a serologic diagnosis of schistosomiasis. (1) However, these techniques are not specific for FGS and, therefore, a "tissue" diagnosis is still required. Detection of eosinophil cationic protein by immunohistochemistry in histologic sections and by enzyme-linked immunosorbent assay in vaginal lavage fluid seems to correlate well with the presence of FGS. However, further study of this "marker" is needed before a diagnostic test can be developed. (14)

The standard of care for treatment of FGS is a single dose of the antiparasitic drug praziquantel at a dose of 40 mg/kg, which eliminates adult worms. Treatment efficacy has been demonstrated by resolution of the clinical lesions, disappearance of circulating schistosome-related antigens in the serum, lack of egg excretion in urine, and lack of viable eggs in follow-up biopsy material. Complete dissolution of degenerating egg material may require months. (15) Before the advent of praziquantel, genital lesions of FGS were considered irreversible and therefore treated surgically. For many cases, therapy with praziquantel is adequate. However, in long-standing cases of FGS with scarring and architectural distortion, a suitable surgical approach may still have to be considered. (2,15)

Conclusion

FGS must enter into the differential diagnosis of symptomatic genital lesions when the clinical history indicates travel to or residence in endemic areas. Once the characteristic eggs are identified by cytologic or histologic methods, appropriate treatment can be initiated, avoiding substantial morbidity.

Accepted October 15, 2002.

Copyright [c] 2004 by The Southern Medical Association

0038-4348/04/9705-0525

References

1. Koneman EW, Allen SD, Janda WM, et al. Parasitology: Blood and tissue parasites, in Color Atlas and Textbook of Diagnostic Microbiology. Philadelphia, Lippincott Williams & Wilkins, 1997, ed 5, pp 1111-1119.

2. Connor DH, Chandler FW, Schwartz DA, et al. Schistosomiasis, in Pathology of Infectious Diseases. Stamford, CT, Appleton & Lange, 1997, vol 2, pp 1537-1551.

3. Feldmeier H, Poggensee G, Krantz I, et al. Female genital schistosomiasis: new challenges from a gender perspective. Trop Geogr Med 1995; 47(2 Suppl):S2-S15.

4. Helling-Giese G, Kjetland EF, Gundersen SG, et al. Schistosomiasis in women: manifestations in the upper reproductive tract. Acta Trop 1996; 62:225-238.

5. Poggensee G, Feldmeier H, Krantz I. Schistosomiasis of the female genital tract: public health aspects. Parasitol Today 1999;15:378-381.

6. Poggensee G, Kiwelu I, Saria M, et al. Schistosomiasis of the lower reproductive tract without egg excretion in urine. Am J Trop Med Hyg 1998;59:782-783.

7. Leutscher P, Ravaoalimalala VE, Ramarokoto CE, et al. Clinical findings in female genital schistosomiasis in Madagascar. Trop Med Int Health 1998;3:327-332.

8. Crump JA, Murdoch DR, Chambers ST, et al. Female genital schistosomiasis. J Travel Med 2000;7:30-32.

9. Poggensee G, Kiwelu I, Weger V, et al. Female genital schistosomiasis of the lower genital tract: prevalence and disease-associated morbidity in northern Tanzania. J Infect Dis 2000;181:1210-1213.

10. Helling-Giese G, Sjaastad A, Poggensee G, et al. Female genital schistosomiasis (FGS): relationship between gynecological and histopathological findings. Acta Trop 1996;62:257-267.

11. Schwartz DA, Hyg MS. Carcinoma of the uterine cervix and schistosomiasis in West Africa. Gynecol Oncol 1984;19:365-370.

12. Leutscher P, Raharisolo C, Pecarrere JL, et al. Schistosoma haematobium induced lesions in the female genital tract in a village in Madagascar. Acta Trop 1997;66:27-33.

13. Kjetland EF, Poggensee G, Helling-Giese G, et al. Female genital schistosomiasis due to Schistosoma haematobium: clinical and parasitological findings in rural Malawi. Acta Trop 1996;62:239-255.

14. Poggensee G, Reimert CM, Nilsson LA, et al. Diagnosis of female genital schistosomiasis by indirect disease markers: determination of eosinophil cationic protein, neopterin and IgA in vaginal fluid and swab eluates. Acta Trop 1996;62:269-280.

15. Richter J, Poggensee G, Kjetland EF, et al. Reversibility of lower reproductive tract abnormalities in women with Schistosoma haematobium infection after treatment with praziquantel: an interim report. Acta Trop 1996;62:289-301.

RELATED ARTICLE: Key Points

* Female genital schistosomiasis is typically not encountered in immunocompetent American women, without a significant travel history.

* Physicians practicing in areas where immigrants from endemic areas (particularly in Africa) have settled should consider female genital schistosomiasis during the workup for genital lesions.

* Direct visualization of schistosome eggs is considered the diagnostic gold standard.

* A single dose of the antiparasitic drug praziquantel is adequate treatment in most cases.

Darian Kameh, MD, Allison Smith, CT (ASCP), Mitzi Scott Brock, MD, Boniface Ndubisi, MD, and Shahla Masood, MD

From the Departments of Pathology and Obstetrics/Gynecology, University of Florida Health Science Center at Jacksonville, Jacksonville, FL.

Reprint requests to Shahla Masood, MD, Department of Pathology, University of Florida Health Science Center at Jacksonville, 655 W. 8th Street, Jacksonville, FL 32209. Email: [e-mail]