VaginalEnterobius vermicularisdiagnosed on liquid-based cytology during Papanicolaou test cervical cancer screening: A report of two cases and a review of the literature

Concomitant ectopic Enterobius vermicularis infection in uterine cervical cancer

BACKGROUND

Enterobius vermicularis (E. vermicularis), also referred to as pinworm, is a widespread human intestinal parasite which predominantly occurs in young children, making their caretakers a population at risk for the transmission of this helminth. It can occasionally affect extraintestinal organs and tissues, including the female genital tract. Infestation can be asymptomatic or manifest as different kinds of gynaecological disorders, such as pelvic inflammation mimicking tumours, abnormal uterine bleeding, or vaginitis. Diagnosis is made by identifying ova in the sample collected from the perineal skin using a transparent adhesive tape or microscopic examination of resected tissue. Mebendazole is the first-line medication and should also be administered to all household members.

CASE PRESENTATION

We present a case of a patient who had undergone surgery for invasive cervical cancer with an accidental finding of E. vermicularis eggs in the cervix.

CONCLUSIONS

Although not very common, infestation with E. vermicularis should be considered in differential diagnoses of various gynaecological disorders accompanied by histological findings of granulomatous inflammation.

Epidemiological Profile and Spatial Patterns of Enterobiasis in Children Aged 3-9 Years in China from 2016 to 2020

(1) Background: Enterobius vermicularis infection causes a significant health burden in children. The infection occurs throughout the country and remains a serious public concern in China. Therefore, it is necessary to know the situation of E. vermicularis infection, to provide a scientific basis for the disease control and the optimum conditions for children's growth. (2) Methods: Descriptive epidemiological analysis was implemented to demonstrate the status and changing trend of E. vermicularis infection from 2016 to 2020, while the spatial distribution characteristics and spatial-temporal clustering were illuminated by spatial autocorrelation analysis and spatio-temporal scanning analysis. (3) Results: The infection of E. vermicularis showed a fluctuating downward trend with a decline of 32.00% in 2020 compared to that in 2016 and was concentrated in central and southern China. There was no significant difference in infection rate between boys and girls, while the high infection rate was presented in 4-, 5- and 6- year-old children. The hotspots and spatial clustering areas were mainly concentrated in southern China. (4) Conclusions: From 2016 to 2020, the infection rate of E. vermicularis in children aged 3 to 9 years in China demonstrated a declining trend, and its distribution showed spatial clustering, mainly in southern China. Therefore, it is necessary to strengthen surveillance and implement control measures in combination with health education and environmental improvement.

Prevalence and genetic analysis of Enterobius vermicularis in schoolchildren in lower northern Thailand

Enterobius vermicularis, a nematode parasite with a global distribution causes enterobiasis in schoolchildren and is considered a neglected parasite. An understanding of the prevalence and genetic diversity of enterobiasis is crucial for appropriate control measures. Therefore, the objectives of this research were to study the prevalence and genetic diversity of E. vermicularis in schoolchildren from lower northern Thailand, based on cytochrome c oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2) sequences. Using the scotch tape technique, 7.4% (188/2544) of schoolchildren from 21 primary schools were found positive for E. vermicularis eggs, which is a relatively low infection rate. Phylogenetic trees of partial COI sequences (397 bp) revealed similar topologies using maximum likelihood (ML) and neighbor-joining (NJ) methods and identified E. vermicularis type A (105 sequences) and B (1 sequence). Haplotype network analysis of the COI sequences demonstrated a high haplotype diversity (H_d = 0.9028). In contrast, phylogenetic analysts of a 343 bp region of the ITS2 locus (52 sequences) revealed a monophyletic group. More sequence analyses of E. vermicularis from humans and other hosts in Thailand are necessary to better understand the genetic diversity of this parasite.

Parasitic Infections of the Gastrointestinal Track and Liver

Parasites have coevolved with humans. Several of them colonize the human body and establish a symbiotic relationship. Other parasites cause severe and lethal diseases. Prevalence of parasitic infections is decreased in highly industrialized countries, largely due to enforced hygienic practices. In contrast, parasites cause significant morbidity and mortality in parts of the world with barriers to effective public hygiene. Some parasites have emerged as potent pathogens in specific patient populations, such as immune suppressed individuals, regardless of sanitation. This article reviews common parasites encountered in clinical practice and, in the setting of host-parasite symbiosis, discusses their immune regulatory role.

Enterobius vermicularis infection: prevalence and risk factors among preschool children in kindergarten in the capital area, Republic of the Marshall Islands

BACKGROUND

Enterobius vermicularis (pinworm) is one of the most common human parasitic helminths, and children are the most susceptible group. Some behavioral and environmental factors may facilitate pinworm infection. In the Republic of the Marshall Islands (RMI), the status of pinworm infections among children remains unknown.

METHODS

In Majuro City, there are 14 kindergartens with a total of 635 preschool children (PSC) whose age range of 5~6 years. The present investigation attempted to determine the pinworm prevalence and associated risk factors as well as investigate whether eggs contaminated the clothes of PSC or the ground and tables in classrooms of 14 kindergartens. Informed consent form and a self-administered questionnaire were given to parents prior to pinworm screening. Perianal specimens were collected by an adhesive scotch tape method, and clothing of belly and hip sites and the ground and tables of the classrooms were inspected using a cellophane tape method to detect any eggs contamination.

RESULTS

In total, 392 PSC (5.28 ± 0.56 yrs. old) participated in this project. The overall prevalence of pinworm infection was 22.4% (88/392). Boys (24.5%) had higher prevalence than girls (20.31%) (p = 0.32). PSC aged > 5 years (32.77%) showed a significantly higher prevalence than those aged ≤5 years (17.95%) (p = 0.01). A univariate analysis indicated that PSC who lived in urban areas (22.95%) had a higher prevalence than those who lived in rural areas (20.69%) (p = 0.69). The employment status of the parents showed no association with the pinworm infection rate (p > 0.05). A logistic regression analysis indicated that "having an older sister" produced a higher risk of acquiring pinworm infection for PSC compared to those who did not have an older sister (OR = 2.02; 95%CI = 1.05~3.88; p = 0.04). No significant association between various other risk factors and pinworm infection was found (p > 0.05). Also, no eggs contamination was found on the clothes of the belly and hip sites or on the ground and tables in the 14 kindergartens.

CONCLUSIONS

Mass screening and treatment of infected PSC are important measures in pinworm control in the RMI.

Rodloff A, Mössner J, Lübbert C. The Diagnosis and Treatment of Pinworm Infection

BACKGROUND

Symptomatic infection with pinworm (Enterobius vermicularis), a human pathogen, is clinically relevant in Germany, with an estimated prevalence in childhood of 2-20%. Enterobiasis can cause major mental distress. There is little systematically verified knowledge on the treatment of this condition, and there is no corresponding German guideline. This review is, therefore, intended as a summary of the current state of knowledge.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed for literature appearing from 1 January 1990 to 5 February 2019 and containing the search terms "enterobiasis," "oxyuriasis," "Enterobius vermicula- ris," "pinworm," and "threadworm."

RESULTS

More than one billion people worldwide are thought to be infected with pinworm. Estimates of its prevalence among kindergarten and primary-school pupils in Europe are generally near 20%. Infants (<2 years of age), adolescents (>14 years of age), and adults are only sporadically affected. The main risk factors are age 4-11 years, uncontrolled anus-finger-mouth contact, nail-biting (onychophagia/peri- onychophagia), unsupervised body hygiene, and poor compliance with basic hand hygiene. No large-scale, randomized, controlled trials of treatment are available. The approved antihelminthic agents are mebendazole, pyrantel embonate, and pyrvinium embonate (success rates up to >90%). For recurrent infections, prolonged treatment for up to 16 weeks (a "pulse scheme") is recommended.

CONCLUSION

In nearly all cases, antihelminthic treatment along with attention to hygienic measures can successfully eradicate pinworm infection and prevent recurrence and autoinfection. The involvement of all persons living in the patient's house- hold, including sexual partners, is a prerequisite to the lasting success of treatment.