Schistosoma mansoni: a rare cause of tubal infection

CASE REPORT

Schistosoma mansoni: a rare cause of tubal infection

Faria CA^I; Conceição JCJ^I; Valadares TF^I; Rodrigues B^I; Carneiro L^II

^IDepartment of Gynecology, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil

^IIDepartment of Pathology, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil

^{Correspondence to}

ABSTRACT

S. haematobium is an important cause of urinary schistosomiasis, and symptomatic female genital infection is a common gynecological finding in areas where S. haematobium is prevalent. On the other hand, genital manifestations of intestinal schistosomas as S. mansoni are not frequent or are misdiagnosed. A case of a 40-year-old woman with abnormal uterine bleeding and asymptomatic tubal infection by S. mansoni identified in histological examination is presented.

Keywords: schistosomiasis, S. mansoni, complications.

INTRODUCTION

Schistosomiasis is a water-based disease which is considered the second most important parasitic infection after malaria in terms of public health and economic impact. At least 600 million people are at risk of infection and 200 million are infected with the worm.¹

The disease is endemic in 76 countries. In Africa and Eastern Mediterranean, S. haematobium causes urinary schistosomiasis and S. mansoni causes intestinal schistosomiasis. Other regions affected by the intestinal form of the disease are the Americas (S. mansoni) and East Asia (S. japonicum and S. japonicum).²

The number of carriers of S. mansoni in Brazil was estimated at 6.3 million in 1997, although there are not precise data about the prevalence of the disease.³

Skin-penetrating infections larvae are released from parasitized freshwater snails and are carried by the blood to the veins draining the intestines or the bladder where they mature, mate, and produce eggs. Eggs cause damage to various tissues, particularly the bladder and liver. The reaction to the eggs in tissues causes inflammation and disease. When infected humans excrete parasite eggs with feces or urine into water, the eggs hatch releasing larvae that in turn infect aquatic snails. In snail, the parasite transforms and divides into second-generation larvae which are released into fresh water ready to infect humans.

There is consistent evidence that S. japonicum can cause female genital tract lesions,^4-8 but the relevance of genital manifestations as a consequence of infection with intestinal schistosomes is not precisely known.⁹

CASE REPORT

A 40-year-old woman with abnormal uterine bleeding, dysmenorrhea and submucous uterine leiomyoma was admitted for surgical treatment. She was born in a Brazilian endemic area for schistosomiasis, and referred contacts with snails from freshwater during childhood. At the age of 16 years, she moved to Rio de Janeiro, where the infection with Schistosoma mansoni is unlikely.

She had 6 pregnancies and 3 miscarriages. The first delivery was at 14 years, and the last pregnancy at 33 years.

A Pfannenstiel laparotomy was performed and revealed firm pelvic adhesions. The uterus was enlarged and irregular, and there was a hemorrhagic cyst in left ovary. Hysterectomy and bilateral adnexectomy was performed.

The postoperative course was normal, and the patient was discharged after three days.

Histological examination of uterus revealed uterine leiomyomata and adenomyosis. The left ovary had a hemorrhagic cyst.

Histological examination of sections of the left fallopian tube showed marked chronic salpingitis with numerous granulomas and schistosoma ova in its wall (Figures 1 and 2).

After diagnosis of tubal schistosomiasis, the patient had a Kato-Katz stool examination that revealed S. mansoni ova (696 eggs/g faeces) with miracidia. She was then treated with oxamniquine.

DISCUSSION

Symptomatic female genital schistosomiasis is a common gynecological finding in areas where S. haematobium is prevalent. In contrast, genital manifestations of intestinal schistosomas are not frequent or are neglected and misdiagnosed.

Because schistosomiasis is a highly prevalent povertyrelated problem, there are few reports of genital involvement by the worm. Major reports come from developing countries and have been published between 1940 and 1960. Genital involvement by S. haematobium is more frequent because adult worms reside in pelvic and vesical venous plexuses, while the others schistosomas live in portal venous system. Nonetheless, there are numerous anastomoses between veins draining genital organs and inferior mesenteric veins. These veins can also have imperfect developed valves, allowing the migration of adult worms of Schistosoma mansoni from territory of the portal vein to that of vena cava inferior.¹⁰

The presence of ova in female genital organs can lead to symptoms, such as lower abdominal pain, dyspareunia, bloody cervical discharge, dysmenorrhea, or pelvic tumors. In many cases, it is asymptomatic. Tubal involvement can produce fibrotic scars, tubal occlusion, and infertility.

Genital schistosomiasis can also complicate pregnancy, causing ectopic pregnancy, abortion, preterm labor, intrauterine growth retardation, and stillbirth.

In this case, the patient had symptoms that could be attributed to leyomioma and adenomyosis. It was not found evidence of uterine involvement by S. mansoni.

Although she also had tubal involvement, she had no evidence of impaired fertility. As her first pregnancy was at age 14, so before she had moved to a non-endemic area, it may be postulated that migration of worms to genital vasculature could have occurred after pregnancy. Physiological adaptations of normal pregnancy enhance the chance of ectopic localization of parasite eggs because pelvic veins are definitely enlarged.

Submitted on: 07/5/2009

Approved on: 08/25/2009

We declare no conflict of interest.

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Publication Dates

• Publication in this collection
  03 Sept 2010
• Date of issue
  June 2010

History

• Received
  05 July 2009
• Accepted
  25 Aug 2009