Schistosomiasis and ruptured ectopic pregnancy: A case report

Abstract

Schistosomiasis is a parasitic disease mainly prevalent in tropical and subtropical areas, especially in poor settings without adequate sanitation and access to clean water. It is caused by trematode parasites living within the veins of their human host, where they mate and produce fertilized eggs. The eggs are either shed into the environment through feces or urine, or are retained in host tissues where they induce inflammation and then die. The genital form is caused by Schistosoma haematobium and affects both the urinary and genital tracts in up to 75% of infected individuals, both male and female. Female genital schistosomiasis is a challenging and potentially lethal condition and may affect the whole genital tract leading to a wide range of urinary, sexual, and reproductive health problems. The main reasons leading women to health services are infertility and genital nonspecific symptoms including vaginal discharge, pruritus, pelvic pain, dyspareunia, and haematuria. Other severe complications caused by schistosomiasis include increased risk of HIV and HPV infection, genital ulcers, miscarriage, and ectopic pregnancy. We report in the present case study a 23-year-old female with schistosomiasis and ruptured ectopic tubal pregnancy successfully managed in a low-income setting.

Introduction

Schistosomiasis, also called bilharzia, is a parasitic disease caused by trematode worms of the genus Schistosoma living within the veins of their human host, where they mate and produce fertilized eggs. ¹ The eggs are either shed into the environment through feces or urine or are retained in host tissues where they induce inflammation and then die. The eggs that reach freshwater will hatch, releasing free-living ciliated miracidia that then infect a suitable snail host. ¹ In the snail, the parasite undergoes asexual replication through mother and daughter sporocyst stages, for 4–6 weeks, before infectious cercariae are released. After cercariae penetrate the skin of the mammalian host, the maturing larvae need approximately 5–7 weeks before becoming adults and producing eggs. Intervals (in both the snail and human) are termed prepatent periods, when the infection is ongoing but release of cercariae (from snails) or eggs (from humans) cannot be detected. Cercariae can remain infective in freshwater for 1–3 days but deplete their energy reserves greatly over a few hours. Eggs—whether excreted or retained in the human body—die within 1–2 weeks after being released by the female worm. ²

The infection is mainly prevalent in tropical and subtropical areas, especially in poor settings without adequate sanitation and access to clean water. ¹ Although it has been reported in almost 80 countries, only 51 are considered endemic with a moderate-to-high risk of transmission and, thus, targeted for large-scale treatment. ¹ It is estimated that more than 250 million people, >90% in Africa, required preventive treatment. Moreover, over 75 million people were treated in 2021 and almost 12,000 deaths occur per year. ¹ The main forms of schistosomiasis include intestinal (Schistosoma mansoni, Schistosoma japonicum, Schistosoma mekongi, Schistosoma guineensis, and related Schistosoma intercalatum) and genital (Schistosoma haematobium). This latter form affects both the urinary and genital tracts in up to 75% of infected individuals both male and female. ³ Female genital schistosomiasis (FGS) is a challenging and potentially lethal condition and may affect the whole genital tract leading to a wide range of urinary, sexual, and reproductive health problems. ⁴

The main reasons leading women to health services are infertility and genital nonspecific symptoms including vaginal discharge, pruritus, pelvic pain, dyspareunia, and hematuria. ⁴ Symptoms are mainly caused by the eggs deposition in female genital tissues generating a long-lasting chronic inflammation. This inflammation is the trigger factor for the clinical picture which is typically composed by nonspecific painful and stigmatizing symptoms such as vaginal discharge, including leukorrhea, itching, contact bleeding, chronic abdominal pain, dyspareunia, and menstrual cycle abnormalities.^5,6 Other severe complications caused by schistosomiasis include increased risk of HIV and HPV infection, genital ulcers, miscarriage, and ectopic pregnancy. ⁷ Despite the high prevalence and potentially harmful consequences, FGS remains unrecognized and underestimated owing to limited specific training for health staff which is likely due to a lack of appropriate equipment especially in rural areas of low-income countries mainly affected by this infection. Importantly, when appropriately and promptly diagnosed, it can be easily treated without health sequela. In particular, the WHO strategy for schistosomiasis control focuses on reducing disease through periodic and regular targeted treatment with praziquantel through the large-scale treatment of affected populations. ¹

In this article, we report on a 23-year-old female diagnosed with ruptured ectopic tubal pregnancy and schistosomiasis successfully managed in a low-income setting.

Case report

A 23-year-old woman, with two previous pregnancies and one live child, gestational age 7 weeks and 1 day, was referred to the hospital for acute abdominal pain and suspected appendicitis. She denied any chronic or past conditions and referred a history of abdominal pain started in the hypogastrium in the past 2 weeks that exacerbated 2 days before admission with diffuse abdominal pain, vaginal bleeding, and amenorrhea.

She had a positive immunological pregnancy test and was transferred to the gynaecology emergency room. At the examination, her blood pressure was 140/80 mmHg, heart rate 105 bpm, and positive Blumberg (i.e., pain upon removal of pressure to the abdomen).

Speculum observation showed clean cervix without lesions, with blood coming out of the external cervical ostium, with slight bulging of the Douglas’s sack. The bimanual examination detected normal-sized uterus, with adnexal mass on the right. On ultrasound, the following was observed: a normal size and structure uterus, trilaminar endometrium, and a right adnexal mass measuring 4 × 3 cm, with limited fluid in the Douglas’s sack. The diagnosis was ruptured ectopic pregnancy (7 weeks + 1 day) and an urgent laparotomy was performed.

Intraoperatively, hemoperitoneum of about 200 ml and the product of conception in the right ampulla were observed (Figure 1), a right total salpingectomy was performed. Histological examination of removed tissues revealed the presence of chorionic villi, abundant triploblastic proliferation and calcified Schistosoma eggs (Figure 2(a) and (b)). After surgery, Praziquantel treatment for 6 weeks was prescribed. Postoperative course was without complication and patient was discharged after 2 days.

Figure 1.

Removed product of ruptured tubal pregnancy.

Figure 2.

(a and b): Histological examination showing chorionic villi, abundant triploblastic proliferation, and calcified Schistosoma eggs (arrows indicate the calcified Schistosoma haematobium eggs in the tissue).

Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

The reporting of this study conforms to the CARE statement. ⁸

Discussion

We report a rare case of a ruptured tubal ectopic pregnancy, with a finding of calcified Schistosoma eggs. Ectopic pregnancy in itself is not a rare finding, especially in emergency department routine practice and most ectopic pregnancies are located in the Fallopian tubes. ⁹ The main causes include infections, surgery, endometriosis, and failed contraception due to intrauterine device or tubal ligation, hormonal, and anatomical preexisting alterations. ¹⁰ Our case is linked to FGS as demonstrated by histologic findings although the relationship between ectopic pregnancy and Schistosoma is far from clear. Indeed, the possible mechanism is not clear and histologic findings range from minimal inflammation to pseudo-tubercle and extensive fibrosis associated with granulomas.^11–13 The most consistent pathogenic hypothesis involves egg-induced fibrotic disruption of tubal function, reducing the luminal calibre, ¹¹ as well as impairing peristalsis, ¹² and therefore favoring ectopic implantation. ¹³ The understanding of the exact mechanism is complicated by other factors such as concurrent infections, especially in areas of sub-Saharan Africa with high prevalence of sexual transmitted diseases including gonococcal infection, HPV, and HIV. ¹⁴ Interestingly, it has been reported that ectopic pregnancy when associated with bilharziasis occurs more often at an earlier age than when it is associated with pyogenic salpingitis. ¹⁵ Also considering the increase of scientific literature, this condition and, more in general, FGS seems to be underestimated, misrecognized, and underdiagnosed.^3,7 In addition to the histologic confirmation, several reliable test are available for diagnosing of FGS including polymerase chain reaction testing of genital specimens, and recombinase polymerase amplification. ¹⁶ Moreover, colposcopy supports in the identification of the lesions, appearing predominantly as single or clustered grains, as homogenous sandy patches, yellow areas, or rubbery papules. ¹⁷ Despite the availability of these reliable tests, a lack of resources, both in terms of equipment and trained health care providers, as observed in the present case, results in a high risk of misdiagnosis with consequent delay in appropriate treatment and, thus, the onset of serious complications.

Moreover, existing treatment is effective, and patients can recover with administration of praziquantel if the infection is treated sufficiently early ¹⁸ ; otherwise, the infection is thought to generate extensive fibrosis leading to infertility among other chronic pathologies. ¹⁹ Moreover, in endemic areas, praziquantel administration is recommended at 40 mg/kg body weight at least twice a year to all individuals older than 2 years and, if Schistosoma prevalence is ⩾10%, the administration is recommended each 6–8 weeks which is the time it takes for the adult worm to mature after infection.

Conclusions

FGS remains a challenging and potentially lethal condition with harmful consequences on the female sexual and reproductive system. In the present case, in a low-income setting, FGS led to a ruptured ectopic pregnancy. The ruptured ectopic pregnancy was successfully treated via surgery (right total salpingectomy) and a 6 week course of praziquantel was administered to treat the FGS per se. Considering the lifecycle of schistosomiasis, poor living conditions allow the infection to enter into the human cycle and limited healthcare settings may result in delayed diagnosis or misdiagnosis, allowing the condition to become chronic. It is therefore of paramount importance to act within a multiple level strategy to increase and improve prevention, screening and early diagnosis, treatment, and research in relation to FGS.