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

Enterobius vermicularis (Pinworm) Appendicitis: The Real Vermiform Appendix

Enterobius vermicularis is the most common helminthic infection in the United States, infecting an estimated 40 million persons. A rare complication of E. vermicularis infestation is appendicitis. The diagnosis must be considered during pathologic examination to ensure appropriate treatment with anti-helminthic therapy.

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.

Detection of Enterobius vermicularis in archived formalin-fixed paraffin-embedded (FFPE) appendectomy blocks: It's potential to compare genetic variations based on mitochondrial DNA (cox1) gene

Acute appendicitis represents one of the most common causes of emergency abdominal surgery worldwide. Meanwhile, Enterobius vermicularis has been suggested as one of the probable causes of appendicitis. In this study, the morphological characteristics of the remnant pinworms and pathologic changes were explored in old-archived FFPE tissues of appendectomies. Moreover, we provide the first molecular identification, genetic, and haplotype variation of this nematode from the old-archived FFPE tissue section of appendectomy using the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Seventeen FFPE appendectomies with E. vermicularis infection, stored over 12-22 years, were collected from two different geographical areas of Iran. In the histopathological examination, tissue changes were observed in thirteen cases (76.4%) and inflammation in four blocks (23.5%). After DNA extraction, the cox1 gene was amplified in twelve (70.6%) cases using the nested polymerase chain reaction (PCR). Phylogenetic analysis and a median-joining network of 78 available cox1 sequences of E. vermicularis revealed 59 haplotypes. We identified five haplotypes that fell into type B. All Haplotypes are novel except for two haplotypes, Hap32 and Hap37, identical to E. vermicularis sequences from Iran, Greece, and Germany. The ranges of diversity distance and haplotype diversity within the isolates were 0-1.9% and HD:0.643-0.667, subsequently. Overall, the absence of inflammation or even tissue changes in some sections can suggest the possible non-inflammatory role of E. vermicularis in appendicitis. Although FFPE material suffers from PCR inhibition, we could successfully use nested PCR to characterize E. vermicularis in old-archived appendectomy blocks and suggest this method as a complementary diagnosis technique in pathology. While the predominant type was B in the Middle East and Europe, further studies on a larger sample size from different geographical regions could probably confirm the results obtained in the present study.

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.

Acute appendicitis caused by Enterobius vermicularis: Observations from a case report

Enterobius vermicularis is the most common parasitic worm responsible for gastrointestinal infection worldwide. Acute appendicitis due to E. vermicularis is a rare infection, affecting mostly the children. In this report, we present the case of a 5-year-old girl infant infected by E. vermicularis found in the appendix lumen. A couple of histopathological and parasitological analyses followed by imaging allowed us to diagnose accurately the etiologic agent. Clinicians should be aware of this parasitosis as a possible cause of acute appendicitis.

Epidemiologic Study of Enterobius vermicularis Infection among Schoolchildren in the Republic of Marshall Islands

The prevalence and risk factors of Enterobius vermicularis (pinworm) infection among primary schoolchildren (PSC) in the Marshall Islands remain unknown; thus, investigation on the status of pinworm infection rate is necessary to establish baseline data. After parents'/guardians' consent, a total of 346 children (179 boys and 167 girls) participated in this study. Individual's perianal area and thumbs were inspected by using the Scotch tape technique and cellophane tape method, respectively. For each child, demographic and risk factor data were collected by a structured questionnaire and statistically analyzed. The overall prevalence of pinworm infection was 12.14% (42/346). Univariate analysis indicated significant differences in PSC who live in an urban area compared to those who live in the rural area (p=0.01). Multivariate analysis still found that PSC who live in the rural area had higher chances to acquire pinworm infection. However, no risk factors were identified to be associated with personal hygiene, sibling number, and parent's educational level or occupation. Nevertheless, a pinworm-like egg was detected on the thumb of one male participant. Children living in the rural area and thumb-sucking behavior are two of the important risk factors of transmitting pinworm infection in the PSC in the Marshall Islands. We suggested an urgent and continuous provision of adequate hygienic sensitization in the school and the community.

Small bowel intussusception and Enterobius vermicularis infestation in a 20-year-old woman

A 20-year-old woman presented with abdominal pain and MRI findings of intussusception of the distal small bowel with no identifiable lead point and no visualisation of the appendix. A diagnostic laparoscopy succeeded in manually reducing the intussusception but was unable to find any candidate lead point. Intraoperatively, hyperperistalsis was observed throughout the small bowel which seemed prone to transient intussusception. Incidental appendectomy revealed an uninflamed appendix with Enterobius vermicularis (pinworm) infestation, the most common parasite present in appendectomy specimens worldwide. Although intussusception in young adults is an uncommon occurrence, the unique nature of this case is amplified by the concurrent finding of E. vermicularis infection of the appendix in an adolescent in western Canada, a phenomenon normally observed in paediatric populations with higher incidence in tropical areas. Although the mechanism of intussusception in this patient remains unclear, it is hypothesised that E. vermicularis colonisation acted as an irritant stimulating intestinal hypercontractility with resulting intussusception. Successful medical eradication of the pinworm in this individual may prevent future recurrence.

Abdominal pain - a common presentation with unusual diagnosis: a case report

Acute abdominal pain is a frequent cause for evaluation in the clinic and emergency room. A number of causes of abdominal pain are diagnosed easily based on the history, physical exam, and some laboratory findings. However, unusual conditions may pose a challenge and require invasive procedures for diagnosis. Rare anomalies such as mobile caecum may present as either typical or atypical acute appendicitis. Endometriosis and pinworm infections can also present as acute appendicitis but are uncommon presentations. To increase the awareness of these uncommon causes of appendicitis, we present a 32 year old female who was previously diagnosed with irritable bowel syndrome later found to have all of the above mentioned rare conditions contributing to abdominal pain. She presented to the emergency room with a one day history of acute right lower quadrant abdominal pain along with nausea and non-bilious vomiting. Physical exam revealed right lower quadrant tenderness to palpation. A computerised tomography of the abdomen and pelvis demonstrated a mobile cecum in the left abdomen. She subsequently underwent a diagnostic laparotomy with cecopexy and appendectomy. Pathology of the appendix showed findings suggestive of endometriosis and intraluminal enterobius vermicularis. She was treated with two doses of pyrantel pamoate for the parasitic infection, and subsequently had resolution of her symptoms.

Enterobius vermicularis causing acute appendicitis, a case report with literature review

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Enterobius vermicularis is one of the commonest parasitic infestations worldwide.

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Its association with acute appendicitis remains controversial.

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It is very rarely encountered during appendectomy.

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In this report, a case of acute appendicitis caused by Enterobius vermicularis has been presented.

Introduction

Enterobius vermicularis is one of the commonest parasitic infestations worldwide but its association with acute appendicitis remains controversial. It is very rarely encountered during appendectomy. The aim of this paper is to report a case of acute appendicitis caused by Enterobius vermicularis. A 23-year-old housewife presented with a right lower abdominal pain for the past 8 h. Clinical examination revealed right iliac fossa tenderness upon palpation and rebound tenderness upon release. The patient was diagnosed as a case of suspected acute appendicitis. The patient was anesthetized and intubated. Delivery of the vermiform appendix done through right grid iron incision. Intra operatively an inflamed appendix obstructed by Enterobius vermicularis was noted.

Conclusion

Enterobius vermicularis can habit the appendix and induce the signs and symptoms of A.A with or without actual histopathological acute appendicitis. The treatment of choice is surgical resection of the appendix.