The Diagnosis and Treatment of Pinworm Infection

Intestinal helminthic infections: a narrative review to guide the hepatogastroenterologist

Intestinal helminthic infections are not uncommon in Western Europe, mainly due to modern travel, emigration and globalization. Moreover, some helminthic infections are endemic in Western Europe and are part of the everyday clinical practice. The hepatogastroenterologist should therefore recognize and manage these patients or at least refer them to appropriate reference centers. Signs and symptoms are often unspecific or even absent. Discerning the disease at an early stage avoids expensive diagnostic testing, life-threatening complications and in some cases even further spread of the disease. This review article aims to guide the hepatogastroenterologist when suspecting a helminthic infection by addressing the most prevalent symptoms, summarizing the most probable associated helminthic entities, highlighting practical steps in diagnosis and available treatments.

Intestinal Parasitic Infections in 2023

Intestinal parasites include intestinal protozoa and intestinal helminths. Intestinal parasitic infections (IPIs) pose a global health problem affecting over one billion people worldwide. Although these infections are predominantly seen in the developing world, they are frequently seen in the developed countries, particularly in immunocompromised patients. Patients' clinical presentations generally include diarrhea, dysentery, abdominal pain, nausea, vomiting, nutritional deficiency, iron deficiency anemia, anal and perianal itching, and rarely intestinal obstruction. The intestinal parasites have similarities in their mode of transmission and life cycle. The stool test is the primary way of diagnosing IPIs. Treatment is given with various anti-parasitic agents. However, appropriate preventive measures are essential for successfully controlling the IPIs.

[Multilocular hepatic masses due to Enterobius vermicularis]

Infestation with Enterobius vermicularis involving extraintestinal manifestation is rare. In a 50-year-old man with lower abdominal pain, computed tomography led to a suspected diagnosis of sigmoid carcinoma with liver metastasis. After ruling out colon cancer by endoscopy, laparoscopic resection of one suspected tumor nodule in the liver was performed. Histopathological examination revealed parasitic granulomas containing pinworms. Hematogenous migration was postulated in the setting of phlebitis with thrombosis of the inferior mesenteric vein.

[Urethritis due to coinfection with Neisseria gonorrhoeae and Enterobius vermicularis in a 27-year-old man]

Urethritis is mainly caused by sexually transmitted pathogens, such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) [1]. Close to 90 million adults are infected annually with NG [2]. Treatment shall be performed according to national guidelines and resistance profiles [2, 3]. Enterobius vermicularis (EV) is the most common helminth in humans with 1 billion people globally infected [4-6]. Symptoms include anal pruritus; however, many infections are asymptomatic [4-7]. A case of urethritis due to simultaneous infection with NG and EV is reported.

Enterobius Vermicularis Infection: A Cross-sectional Study in Preschool and School Children in the North-Western Part of Slovenia

Enterobius vermicularis is a prevalent intestinal nematode. The objective of the research was to study enterobiasis prevalence in symptomatic children <15 years of age attending community health center in North - Western part of Slovenia in years 2017 - 2022. Perianal tape tests were performed on three consecutive days. The overall prevalence was 34.2 % (296 out of 864 children included). The mean age of children positive for E. vermicularis was 5.77 (95 % CI: 5.51 - 6.04) and 4.74 (95 % CI: 4.54 - 4.95), p<0.001 for children with negative test results. The positivity rate was not significantly different for boys compared to girls (boys 37.0 %, 95 % CI: 32.4 % - 41.8 %, girls 31.8 %, 95 % CI: 27.6 % - 36.2 %, p=0.107). The number of boys with all three samples positive in a sample set was higher compared to girls (p - value 0.002). Family size affected the positivity rate - the mean number of siblings was higher in positive children. Significant association with E. vermicularis infection was proven by the presence of anal pruritus and absence of abdominal discomfort. High E. vermicularis warrants careful monitoring of trends and public health response. It is necessary to encourage the use of hygiene measures in schools and empower parents to recognize enterobiasis timely.

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.

Knowledge and Practice of Pinworm Infection in Preschool Children, Jiangsu Province, China, 2019-2020

We conducted a two-year (2019-2020) longitudinal study in Jiangsu Province, China to analyze risk factors of pinworm infection and evaluate the effect of behavior change communication-based (BCC-based) interventions in preschool children. The positive rate of pinworm infection was higher in private preschool (2%) than in public preschool (0.24%). Poor sanitation behaviors were risk factors among private preschool children. BCC-based intervention could improve knowledge and practice and reduce pinworm infection. This study may help fill in gaps in pinworm control. (Am J Public Health. 2022;112(12):1716-1720. https://doi.org/10.2105/AJPH.2022.307067).

Is pinworm infection still a public health concern among children in resource-rich regions? Trends in pinworm infection prevalence and associated factors among children in Hualien County, Taiwan: a retrospective cross-sectional study

BACKGROUND

Enterobius vermicularis (pinworm) is a common intestinal parasitic infection in children. A gradual decrease in the prevalence of pinworm infection has been noted in resource-rich settings, such as Taiwan. However, the influence of sociodemographic factors on the temporal trend in pinworm infection rates in children under the current pinworm infection prevention policy in Taiwan is not well characterized. This study aimed to evaluate the trend of pinworm infection prevalence and the associated factors among children in Hualien County, Taiwan.

METHODOLOGY

In this retrospective cross-sectional study, we included a total of 56,197 students (aged 6-10 years) in grades 1 and 4 in Hualien in 2009-2018. Children were screened for pinworm infection using adhesive cellophane perianal swabs in the routine student health examination. Logistic regression was conducted to evaluate the factors associated with pinworm infection. Associations between dependent and independent variables were measured by odds ratios. The Cochran-Armitage test was used to assess whether there were significant trends in different stratifications. Variables with P-values < 0.05 were considered statistically significant.

RESULTS

A total of 56,197 school-age children from grades 1 and 4 during 2009-2018 were included. Young age and male sex were risk factors for pinworm infection (P < 0.001). A negative correlation between body mass index and enterobiasis was observed, and decreased pinworm infection was noted during the study reference period. Children living in suburban and rural areas had higher odds of having a pinworm infection than those living in urban areas (P < 0.001). A significant decrease in the overall prevalence rate of pinworm infection was observed among children in 2009-2018 (P < 0.001). However, there was no obvious change in the pinworm infection rate in rural areas during this period (P = 0.953), and it was higher than that in urban and suburban areas.

CONCLUSIONS

The overall prevalence of pinworm infection gradually decreased from 2009 to 2018 among school-age children in Hualien. However, there was no declining trend in pinworm infection in rural areas. Young age, male sex, and rural residence were significantly associated with pinworm infection. Pinworm infection remains a major public health concern among children in rural areas of Hualien.

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.

Helminth-Induced Human Gastrointestinal Dysbiosis: a Systematic Review and Meta-Analysis Reveals Insights into Altered Taxon Diversity and Microbial Gradient Collapse

High-throughput 16S rRNA sequencing has allowed the characterization of helminth-uninfected (HU) and helminth-infected (HI) gut microbiomes, revealing distinct profiles. However, there have been no qualitative or quantitative syntheses of these studies, which show marked variation in participant age, diet, pathogen of interest, and study location. A predefined minimally biased search strategy identified 23 studies in humans. For each of these studies, we qualitatively addressed the effects of helminth infection on within-individual (alpha) and between-individual (beta) fecal microbiome diversity, infection-associated microbial taxa, the effect of helminth clearance on microbiome composition, microbiome composition as a predictor of infection status or treatment outcome, and treatment-specific effects on the fecal microbiome. Concomitantly, we performed a meta-analysis on a subset of 7 of these studies containing raw, paired-end 16S reads and individual-level metadata, comprising 424 pretreatment or untreated HI individuals and 497 HU controls. After reducing the batch effect and adjusting for age, our data demonstrated that intestinal helminth parasites can alter the host gut microbiome by increasing alpha diversity and promoting taxonomic reassortment and gradient collapse. Most strongly influencing the microbiome composition were the helminths found in the large intestine, Enterobius vermicularis and Trichuris trichiura, suggesting that this influence appears to be specific to soil-transmitted helminths (STH) species and host anatomical niche. In summary, using a large and diverse sample set captured in the meta-analysis, we were able to evaluate the influence of individual helminth species as well as species-species interactions, each of which explained a significant portion of the variation in the microbiome.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Bile duct infestation with Enterobius vermicularis diagnosed after cholecystectomy: About two case reports

Intestinal infestation with Enterobius vermicularis is common, especially in the developing countries. However, its migration in the bile ducts is rare, often diagnosed after cholecystectomy. More investigations are needed to define its involvement in symptoms presented by patients and the likelihood of complications.

Natural Products Are a Promising Source for Anthelmintic Drug Discovery

Parasitic nematodes infect almost all forms of life. In the human context, parasites are one of the major causative factors for physical and intellectual growth retardation in the developing world. In the agricultural setting, parasites have a great economic impact through a reduction in livestock performance or control cost. The main method of controlling these devastating conditions is the use of anthelmintic drugs. Unfortunately, there are only a few anthelmintic drug classes available in the market and significant resistance has developed in most of the parasitic species of livestock. Therefore, development of new anthelmintics with different modes of action is critical for sustainable parasitic control in the future. The drug development pipeline is broadly limited to two types of molecules, namely synthetic compounds and natural plant products. Compared to synthetic compounds, natural products are highly diverse, and many have historically proven valuable in folk medicine to treat various gastrointestinal ailments. This review focus on the use of traditional knowledge-based plant extracts in the development of new therapeutic leads, the approaches used as screening techniques, and common bottlenecks and opportunities in plant-based anthelmintic drug discovery.

Niclosamide and Pyrvinium Are Both Potential Therapeutics for Osteosarcoma, Inhibiting Wnt-Axin2-Snail Cascade

Simple Summary

Epithelial–mesenchymal transition (EMT) regulated by Wnt signaling is known as a key mechanism of cancer progression. Although evidence has suggested that the oncogenic Wnt signaling pathway and EMT program are important in the progression of osteosarcoma, there is no known therapeutic drug targeting EMT for osteosarcoma. We investigated whether Axin2, an important EMT target, could be a suitable molecular target and biomarker for osteosarcoma. Furthermore, we showed that both niclosamide and pyrvinium target Axin2, and effectively induce EMT reversion in osteosarcoma cell lines. Our findings suggest an effective biomarker and potential EMT therapeutics for osteosarcoma patients.

Abstract

Osteosarcoma, the most common primary bone malignancy, is typically related to growth spurts during adolescence. Prognosis is very poor for patients with metastatic or recurrent osteosarcoma, with survival rates of only 20–30%. Epithelial–mesenchymal transition (EMT) is a cellular mechanism that contributes to the invasion and metastasis of cancer cells, and Wnt signaling activates the EMT program by stabilizing Snail and β-catenin in tandem. Although the Wnt/Snail axis is known to play significant roles in the progression of osteosarcoma, and the anthelmintic agents, niclosamide and pyrvinium, have been studied as inhibitors of the Wnt pathway, their therapeutic effects and regulatory mechanisms in osteosarcoma remain unidentified. In this study, we show that both niclosamide and pyrvinium target Axin2, resulting in the suppression of EMT by the inhibition of the Wnt/Snail axis in osteosarcoma cells. Axin2 and Snail are abundant in patient samples and cell lines of osteosarcoma. The treatment of niclosamide and pyrvinium inhibits the migration of osteosarcoma cells at nanomolar concentrations. These results suggest that Axin2 and Snail are candidate therapeutic targets in osteosarcoma, and that anthelminthic agents, niclosamide and pyrvinium, may be effective for osteosarcoma patients.

Intestinal Parasitoses among Chepang and Musahar Community People of Makwanpur and Nawalparasi Districts of Nepal

BACKGROUND

Intestinal parasitosis is one of the commonly perceived serious problems often observed in children leading to high mortality. The objective of the study was to identify the intestinal parasites and study their prevalence in the two mostly disadvantaged communities (Musahar and Chepang) of Nepal.

METHODS

This was a cross-sectional study conducted in the Musahar and Chepang communities of Nepal from April to October 2019. A total of 205 random stool samples were collected in dry, clean and screw-capped plastic containers and mixed with 2.5% potassium dichromate solution. A pre-structured questionnaire was used to collect data on predisposing factors. The laboratory examination of the stool samples was done by direct microscopy and further confirmed by concentration methods (formalin ether sedimentation technique and flotation technique using Sheather's sugar solution), and modified acid-fast staining. Detection of eggs of Enterobius vermicularis was done by cellophane tape method.

RESULTS

The overall prevalence of intestinal parasitic infection was found to be 36.6%, with a similar prevalence in the Chepangs (39.8%) and in the Musahars (33.3%) (P > 0.05). The most predominant helminth was Ascaris lumbricoides (15.6%), while the most prevalent protozoan was Entamoeba histolytica/dispar (5.4%). The study also assessed a significant association between the prevalence of parasites with socio-demographic factors, types of drinking water consumption and sanitation habits of the people (P < 0.05).

CONCLUSION

The findings of the study suggest a need for formulating effective preventive and control strategies against intestinal parasitic infections along with the continuity of mass deworming program.

Enterobius vermicularis in appendectomy specimens; Clinicopathological assessment: Cross sectional study

BACKGROUND

This study identifies the incidence of appendiceal Enterobius vermicularis (E.v) infestation in all the patients undergoing appendectomy and evaluates the relationship between E. v infestation of the appendix and the acute appendicitis.

METHOD

ology: All the routinely examined appendectomy specimens received in the pathology laboratory of a referral hospital over a three year period of time were reviewed for the existence of E. v. These cases were evaluated for clinico-laboratory characterization.

RESULTS

Out of 1150 appendectomies for clinical acute appendicitis picture, 31 (2.7%) cases revealed E. v infestation. The age ranged from 6 to 42 years old but more than 80% of the E. v infected cases were children. Twenty four cases (77.4%) did not show any other appendiceal pathology, six cases showed lymphoid hyperplasia and only one case showed concomitant histological acute inflammatory process.

CONCLUSION

E. v infestation is an incidental finding during histopathology examination of appendectomy specimens for patients with clinical diagnosis of acute appendicitis, however there is no relation between the existence of E. v and occurrence of acute appendicitis which is the main indication for appendectomy, so further studies are recommended to reach out earlier diagnosis to eliminate the unnecessary surgical intervention. Also surgeons should consider E. v as a differential diagnosis when removing a normal looking appendix to take the necessary precautions for minimizing any chance of contamination and sending all the normal looking appendectomy specimens for histopathology examination.

Chronic nail biting, orthodontic treatment and Enterobacteriaceae in the oral cavity

Background

Chronic nail biting is common in children and young adults. Auto inoculation of environmental pathogens can manifest as infection in distant organs. Multi-drug resistance gram negative bacteria are on the rise globally. Several of the foodborne bacteria fall within the Enterobacteriaceae family but very few studies have explored these microbes in the oral cavity of children with chronic nail-biting habit or orthodontic treatment. The study aims to investigate oral load of Enterobacteriaceae in children with chronic nail-biting habit and or those undergoing orthodontic treatment.

Material and Methods

150 children (no nail-biting n=30, nail biting n=60, fixed orthodontic treatment n =30 and a combination of fixed orthodontic appliance use and nail-biting habit n =30) were assessed for culture based microbiological investigation. The concentrated oral rinse technique was used. The rinse was inoculated in MacConkey’s and Blood Agar. The gram stained culture was subjected to biochemical tests for sub-species identification using Biomerieux Vitek 2 Compact Automated Microbiological Analyzer. Fisher’s exact and Kruskal Wallis with post hoc analysis using Dunn method was performed to test association and difference between groups.

Results

Enterobacteriaceae was positive for 72% of the children. Of them, nail biting or orthodontic treatment group comprised 89%. Those with a combination of nail biting and undergoing orthodontic treatment exhibited highest CFU/ml and those without nail biting or orthodontic treatment exhibited the lowest. Three of the four organisms isolated tested positive in the orthodontic treatment group. E. coli was positive in 38% of the children while Klebsiella and E. cloacae were isolated exclusively in the orthodontic treatment group.

Conclusions

Chronic nail biting or the use of fixed orthodontic appliances is associated with higher incidence of Enterobacteriaceae in the oral cavity. Oral health professionals play an important role in preventing multi drug resistance infectious diseases.

Key words:Enterobacteriaceae, nail-biting, Onychophagia, orthodontic treatment.