Enterobius vermicularis salpingitis seen in the setting of ectopic pregnancy in a Malaysian patient

Fatal Case of a Child Harboring Enterobius vermicularis

Enterobius vermicularis is a threadlike parasite also known as "pinworms". It is the most common helminth infection, affecting the gastrointestinal tracts of children worldwide, although it seldom causes any fatalities. Enterobius vermicularis infections are usually asymptomatic and may only cause anal pruritis, with occasional reported cases of ectopic migration into the appendix or the female genital tract by adult pinworms. Here, we report a case of a 15-year-old girl who presented to the emergency department with high-grade fever, vomiting, and vague abdominal pain for three days. She was diagnosed with acute abdominal pain and underwent emergency ileocecectomy, but died the following day. Pathological examination of ileocecal junction showed intraluminal and intramural Enterobius vermicularis, which were attributed as the cause of her death in the absence of any other pathologies. Death due to Enterobius vermicularis is rare; this case calls for clinicians to be vigilant in exploring Enterobius vermicularis infections in patients with undiagnosed acute abdominal pain, since it could be a potential cause of death.

A Large Adnexal Tumor Caused by Enterobius Vermicularis Mimicking Malignancy

Enterobius vermicularis usually causes trivial infections in the juvenile population. However, its extragenital presentation in adults is relatively rare. We present the case of a 64-year-old female suffering from poorly controlled diabetes and lower abdominal pain. CT scan showed a large tumorous expansion of the lower abdomen, mimicking malignancy. Perioperative findings revealed a large adnexal tumor adhering to the rectum. In addition, the histological examination uncovered a mixed inflammatory infiltrate with multiple surrounding eggs of the parasite and granulomatous reaction in the left fallopian tube and left ovarian cortex. As reported in our article, the rare ectopic sites of Enterobius vermicularis in postmenopause may become a diagnostic challenge.

A PCR-based method for the diagnosis of Enterobius vermicularis in stool samples, specifically designed for clinical application

BACKGROUND

Enterobius vermicularis (E. vermicularis) is a nematode that infects up to 200 million people worldwide, despite effective medications being available. Conventional diagnostic tests are hindered by low sensitivity and poor patient compliance. Furthermore, no biomolecular techniques are available for clinical application. The aim of this study was to develop a procedure specifically designed for clinical application to detect E. vermicularis by means of PCR.

MATERIALS AND METHODS

Two subject groups were taken into account: a group of 27 infected patients and a control group of 27 healthy subjects. A nested-PCR was performed on fecal samples to detect E. vermicularis. Due to the intrinsic difficulties of the fecal matrix, several countermeasures were adopted to ensure the efficient performance of the method: (a) a large amount of feces for the extraction process (20 g instead of 200 mg); (b) a combination of chemical and physical treatments to grind the fecal matrix; (c) an additional purification process for the negative samples after the first nested-PCR; and (d) the selection of a very specific target region for the PCR.

RESULTS

Due to the lack of overlap with other organisms, a sequence of the 5S ribosomal DNA (rDNA) spacer region including the tract SL1 was chosen to design appropriate external and internal primers. The first nested-PCR detected E.vermicularis in 19/27 samples from infected patients. After further purification, 5/8 of the negative samples resulted positive at the second PCR. Conversely, all the samples from healthy controls resulted negative to both PCRs. Sensitivity and specificity of the method were, respectively, 88.9% and 100%.

CONCLUSION

The results prove the high diagnostic accuracy of the proposed method, addressing and overcoming the challenges posed by both conventional tests and PCR-based approaches. Therefore, the method can be proposed for clinical application.

Enterobiasis and its risk factors in urban, rural and indigenous children of subtropical Argentina

A cross-sectional survey to assess the prevalence of Enterobius vermicularis infection and its associated factors among the child population of infant, preschool and school age in the urban, rural and indigenous population of Iguazú city, in subtropical Argentina was presented. Additionally, the status of enterobiasis at country level was reviewed and analysed. Enterobius vermicularis presence was assessed employing an oviscopic serial sampling technique. Statistical analysis of socio-demographic determinants was performed by generalized linear mixed models at individual, household and community levels. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used to gather national information about E. vermicularis prevalence spanning the decade 2010–2020. A total of 916 children from 470 families participated. Overall prevalence was 29.8%, with 25.3, 30.7 and 34.2% detected for children inhabiting urban, rural and indigenous villages, respectively. The multi-level analysis showed that the presence of E. vermicularis was mostly determined by individual (e.g. age, playing habits, previous pinworm infection) and household-level factors (e.g. family size, overcrowding conditions). Interestingly, WASH variables, such as waste disposal, analysed at community level were also important. Data were analysed to provide eco-epidemiological features of enterobiasis in a heterogeneous subtropical child population in the same territory but with different socio-sanitary realities. The importance of promoting multi-level actions against the determinants identified, to control this public health problem integratively was evidenced. The scoping review of national data updated the state of knowledge of this parasitosis, identifying risk determinants and gaps in knowledge at country level.

The neglected role of Enterobius vermicularis in appendicitis: A systematic review and meta-analysis

Although the main cause of appendicitis is unclear, infection with Enterobius vermicularis is suggested as a neglected risk factor. Since, there is no comprehensive analysis to estimate the prevalence of E. vermicularis in appendicitis; therefore, we conducted a global-scale systematic review and meta-analysis study to estimate the prevalence of E. vermicularis infection in appendicitis cases. PubMed, Scopus, Web of Science and Google Scholar databases were systematically searched for relevant studies published until 15 August 2019. Pooled prevalence of E. vermicularis infection was estimated using the random effects model. Data were classified based on the continents and countries. Moreover, subgroup analyses regarding the gender, the human development index (HDI), and income level of countries were also performed. Fifty-nine studies involving 103195 appendix tissue samples belonging to the individuals of appendicitis were included. The pooled prevalence of E. vermicularis infection was (4%, 95%CI, 2–6%), with the highest prevalence (8%, 95% CI: 0–36%) and lowest prevalence (2%, 95% CI: 1–4%) in Africa and Americas continents, respectively. With respect to countries, the lowest and highest prevalence rates were reported from Venezuela (<1%, 95% CI: 0–1%) and Nigeria (33%, 95% CI: 17–52%), respectively. Indeed, a higher prevalence was observed in females, as well as in countries with lower levels of income and HDI. Our findings indicate the relatively high burden of E. vermicularis infection in appendicitis cases. However, our findings suggest the great need for more epidemiological studies to depth understand overlaps between E. vermicularis infection and appendicitis in countries with lower HDI and income levels.

Association of pelvic inflammatory disease (PID) with ectopic pregnancy and preterm labor in Taiwan: A nationwide population-based retrospective cohort study

Background

Pelvic inflammatory disease (PID) is an infectious disease that causes tubal occlusion and other pelvic and abdominal adhesions. The incidence of pelvic inflammatory disease (PID) has increased due to the sexually active status of the young population. This leads to a more serious problem and a larger effect than previously observed. However, there have been few studies on this topic in Asian populations.

Aim

We aimed to evaluate the risk of preterm labor and/or ectopic pregnancy in Taiwanese women following PID.

Design

Using the Taiwan National Health Insurance Database, we designed a retrospective cohort study that included 12- to 55-year-old pregnant women between 2000 and 2010. We selected a 1:3 age-matched control group of non-PID women. The endpoint was any episode of preterm labor or ectopic pregnancy; otherwise, the patients were tracked until 31 December 2010.

Methods

The risk factors for preterm labor or ectopic pregnancy were explored. For cases included from the index date until the end of 2010, we analyzed the risk of incident preterm labor or ectopic pregnancy. With the use of a multivariate Cox proportional hazard regression analysis, we calculated the hazard ratio (HR) with a 95% CI and compared it with that of the control group.

Results

This study examined 30,450 patients with PID and 91,350 controls. During the follow-up period, patients in the PID group were more likely to develop preterm labor or ectopic pregnancy than patients in the control group. The cumulative incidence rates for developing preterm labor were 1.84% (561/30,450 individuals) in patients with PID and 1.63% (1492/91,350 individuals) in patients without PID. On the other hand, the cumulative incidence rate for developing ectopic pregnancy in patients with PID was 0.05% (14/30,450 individuals) but was only 0.04% (33/91,350 individuals) in patients without PID. Compared with those without PID, the patients with PID had a 1.864 times (P<0.001) higher risk of developing preterm labor and a 2.121 times (P = 0.003) higher risk of developing ectopic pregnancy.

Conclusion

Our study provided evidence of an increased risk of preterm labor or ectopic pregnancy in PID patients.

Gynecological and obstetrical aspects of Enterobius vermicularis infection

Enterobiasis is an easily recognizable and treatable disease with higher incidence among children. Based on these facts, its clinical importance is usually underestimated. This infection also occurs during adulthood and without treatment, it can cause severe complications in some rare cases. Unnoticed subclinical infection in women can lead to infertility and even to life-threatening conditions. It is also emphasized in this paper that the treatment of identified enterobiasis during pregnancy needs caution. After reviewing the current scientific literature, two gynecological cases are presented here.

Acute suppurative appendicitis associated with Enterobius vermicularis: an incidental finding or a causative agent? A case report

Background

Histological acute appendicitis patterns associated with Enterobius vermicularis is an extremely rare finding. The exact role of this parasite in acute appendicitis is controversial as usually resected specimens show no evidence of histological inflammation.

Case presentation

We present herein a case of a 21-year-old male Arabic patient who presented with clinical syndrome of acute appendicitis. Emergency appendectomy was performed and the histopathological examination of the resected specimen showed the presence of E. vermicularis as well as intense acute inflammatory patterns such as mucosal ulceration and suppurative necrosis. The post-operative course was uneventful and the patient was discharged with appropriate anti-helmintic drug prescription.

Conclusion

Acute appendicitis due to E. vermicularis is a very rare occurrence. The histopathological analysis of resected specimens should pay special attention to search for this parasite for adequate post-operative treatment of patients.

Enterobius vermicularis in the Endometrium of the Uterus: A Case Report

Enterobius vermicularis is an intestinal nematode of humans and the most common helminth infection. Main transmission path is direct contact between infected and uninfected person meaning ingestion of the eggs. Human infections are usually asymptomatic or manifest as perianal itching. Although ectopic locations are uncommon, Enterobius can occasionally be detected in appendix, kidney, male urinary tract and female genital tract. We present a case from Varaždin General Hospital, Varaždin, Croatia in 2012, involving a 90-yr-old female patient who underwent hysterectomy leading to accidental finding of E. vermicularis in the uterus despite being asymptomatic for enterobiasis. Since there were no signs and symptoms of parasitic infection, no antiparasitic drugs were administered. Parasite was not observed during macroscopic examination, yet microscopic examination of the material demonstrated helminth within endometrium surrounded by dense inflammatory infiltrate, predominantly lymphocytes and some eosinophils. Internal structures of the parasite were collapsed, while well-developed musculature and cuticle were preserved. We present this case to educate and remind physicians on this parasitosis as possible diagnosis. Although non-gastrointestinal locations of Enterobius infestation are rare, this infection should be considered in patients with abdominal pain, genitourinary symptoms, and pelvic pain in order to apply appropriate treatment and prevent further complications.