Christine Dubray. INFECTIOUS AGENT. The intestinal nematode (roundworm) Enterobius vermicularis. TRANSMISSION. Egg transmission. Pinworm infection, also known as enterobiasis, is a human parasitic disease caused by the pinworm. The most common symptom is itching in the anal area. Enterobius vermicularis(pinworm) andTrichuris trichiura(whipworm) are two of the most common nematode infections biasis.
|Published (Last):||6 January 2013|
|PDF File Size:||10.98 Mb|
|ePub File Size:||14.32 Mb|
|Price:||Free* [*Free Regsitration Required]|
Both the clinical and the histopathological diagnostic difficulties of oxyuriasis in unusual sites and their importance from a clinical point of view are pointed out. The authors report two ectoptic cases of enterobiasis observed in Northern Italy, oxiiriasis located in a fallopian tube of a year-old woman and the other in a perianal subcutaneous tissue of a year-old man, mimicking tumor-like lesions.
Enterobius vermicularis Nematoda, Oxyuridae is a very common parasite, perhaps the most common among the helminths which are considered strictly specific for man [ 1 ], even if it has been argued recently that E.
The parasite is not transmitted by arthropod vectors or intermediate hosts but directly from the parasitized subject to a healthy subject by means of hands, food, or contaminated objects. An indirect transmission by air has also been shown for human enterobiasis, since its microscopic eggs are capable of being released in the air and inhaled with dust [ 5 ].
Its existence, well known since ancient times, is not clearly influenced by climatic differences so that the helminths can really be considered cosmopolitan, found from tropical zones [ 6 ] to polar zones [ 7 ] and from different socioeconomic situations [ 8 ].
In fact, it is present in the same region both in the rich and the poor. Even though it is prevalent in children, in particular in scholastic communities, it is, however, reported in subjects of all ages, sometimes mild and of scarce importance but other times with notable problems due to the frequent involvement of the coenesthesia, complications due to microbic infections oxiuuriasis a result of lesions from scratching oxiufiasis not easily controlled chronic forms which can sometimes be complicated by psychoneurotic involvement.
During the cycle of the parasite the female, once fertilized, descends into the rectum from its habitual location, the caecum and the colon, and lays its eggs in the anal folds and the surrounding areas.
CDC – Enterobiasis
enteroblasis The deposited eggs mature in a few hours and contain fully developed larvae becoming infective. The movements of the females and the laying of the eggs cause itching, predisposing the passage of the infection to the same patient or other patients through hands which have been contaminated enrerobiasis this way.
Parasitosis in these locations is easily able to be diagnosed by means of specific parasitological pxiuriasis perianal swabs or the Scotch cellophane tape test. Self-infestation is frequent and can cause long-term infections. It occurs either through one of the above-mentioned mechanisms or through so-called retrofection [ 9 ] and, therefore, with the hatching of the eggs outside the anal sphincter followed by a retrograde ascent into the rectum on the part of the emerged larvae [ 10 ].
Retrograde infection of E.
In female subjects, E. In such cases, clinical diagnosis is impossible, and the diagnosis can only be reached histologically, generally representing an unexpected surprise for the histopathologist.
Enterobissis the report of two recent ectopic cases, one located in a Fallopian tube and the other in a perianal abscess, which recently came to our attention. A year-old nomadic Yugoslavian woman without a fixed abode, was referred urgently to Voghera Hospital Northern Italy in January for an acute abdomen.
From the anamnesis, collected with difficulty due to the language problems, it turned out that the patient had been suffering from painful crises in the lower abdominal quadrants for many years. As the pain had become unbearable, the patient asked for medical aid. When the abdomen was opened, the surgeon found a bilateral tubal-ovarian abscess, associated with diffuse peritonitis.
Both adnexa were removed. Other more or less linear structures, probable remnants in an advanced regression phase of the uterine wall of the nematode, were also visible at the periphery of the egg cluster Figure 1 b.
Histological aspects of ectopic locations of E. A year-old man, living in the country near Modena, was admitted to Vignola Hospital Modena, Northern Italy in March for perianal swelling which had been present for about a year but which had become highly painful about three weeks before, in particular while defecating.
Fifteen years previously, the patient had undergone chemotherapy because he had a non-Hodgkin’s lymphoma which had regressed but recurred after 8 years and was currently inactive under pharmacological control.
On physical examination, a rounded mass having a diameter of about 2 cm, externally palpable in the posterior quadrants of the perineum, highly painful at palpation, having a hard-elastic consistency, with the skin moderately reddened was noted.
Rectal exploration, which was painful, demonstrated that the mass was located in the perianal oxiriasis tissue. Neither oxiuraisis nor rhagades were observed. The nodular tumor-like lesion, enucleated surgically through the skin was examined histologically and was composed of cutaneous and subcutaneous tissues with partially obliterated fistulous pathways which communicated deeply into the suppurative area with inflammatory and chronic infiltrations and with the presence of a plurinucleate giant cell granuloma, foreign body type, fibrous tissue, lymphocytes, and numerous eosinophilic granulocytes mingled with necrotic material Figure 1 c.
In the context of the fistula, minute pilar fragments and keratin lamellae remnants of a pilonidal cyst were found. Peripheral eosinophilia was not found nor were parasite eggs using the Scotch-tape test. Therefore, a diagnosis of pilonidal cysts with oxyuris eggs was made in an individual under chemotherapeutic treatment for non-Hodgkin’s lymphoma. In the first case, it would seem, therefore, that the worm had gone back up the genitals and, after penetrating the thickness of the tubal wall which had probably already been damaged by other infective agents, it was halted by the defensive reaction of the host tissues and remained among the inflammatory cells.
Enterobiasis in Ectopic Locations Mimicking Tumor-Like Lesions
Similar cases have been reported over the last decade by many authors [ 1532 — 34 ]. Regarding the second case, the presence of E. The state of evident immunodepression may most likely have enteroibasis this unusual location. From a review of the literature, location in the female genital tracts, considering as such also those peritoneals at the pelvic level according to Symmers, [ 27 entedobiasis described from the end of the enterkbiasis [ 9 ] to today are not, in reality, entedobiasis rare as one might think; in fact, we were able to find more than 80 cases, reported in 24 different countries of 3 continents France, UK, USA.
Almost and always were the females of E. The ova appear to be considerably more resistant than the worm itself, enherobiasis they remain well-preserved even when the latter is scarcely recognizable in the lesions or has completely disappeared. A good review of cases with such locations was already published in by Symmers [ 27 ] and then in by Sun et al. In the differential diagnosis of these locations, granulomas of different origins can be taken into consideration: Finally, some granulomas correlated to the presence of Schistosoma spp.
Cases of perianal locations are less frequently reported; from the first case published by Froelich in [ 16 ] to the present case, the scientific literature has reported only 24 cases associated with E. A review of cases of enterobiasis in this location was reported in by Avolio et al.
For the most part, the onset of the nodule is more or less painful, especially after defecation. It can be associated with a ehterobiasis sensation or anal itching. The ulceration of the nodule is possible but has not been ascertained the nature of the event: Digital exploration of the rectum detects the presence of the nodule, more or less firm, painful at palpation, having a diameter of cm.
If it is not very painful, the nodule is tolerated by the patient, even for a number of months, before seeing a doctor Vafai and Mohit, [ 18 ]; also see our case 2. Normally, eosinophilia is not reported. The diagnosis is based on the histological finding.
In two cases, the diagnosis was eenterobiasis, with typical eggs having been found by means of fine needle aspiration [ 3940 ]. Among the other granulomatous lesions which may enterobiasus confused with perianal lesions from E.
If the patient comes from a snterobiasis endemic for bilharziasis, the differential diagnosis must include the granulomas caused by the eggs of Schistosoma haematobium or other species of trematodes of the same genus. Many cases located both in the female genital tract and in the ano-rectal zone could also be not diagnosed since sometimes notable symptoms are not present and other times due to the diagnostic error of the histopathologist. The current teaching in medical schools, unjustly relegates oxyuriasis to a very limited space.
But its impact on human health is not irrelevant, given the possible long duration of the infection, the possible obstinate resistance ociuriasis the therapy and the possible ectopic locations which are difficult to diagnose clinically.
Nowadays, recent progress in the biology enterobiaxis pinworms based on techniques of extractive molecular biology can be used to overcome the difficulty of the clinical diagnosis and also to identify the provenance of the pinworm: Moreover, molecular biology succeeded in clarifying the taxonomy of Enterobius gregorii by which Hugot supposed to be a new parasite for humans.
Indeed, according to Nakano et al. Consequently, molecular evidence is that E. The authors would like to thank the Mrs. Luca Fabbiani for ooxiuriasis technical support. National Center for Biotechnology InformationU.
Journal List Int J Microbiol v. Published online Jun Author information Article notes Copyright and License information Disclaimer. Received Nov 13; Accepted Mar This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any enterobisis, provided the original work is properly cited.
This article has been cited by other articles in PMC. Abstract Both the clinical and the histopathological diagnostic difficulties of oxyuriasis in unusual sites and their importance from a clinical point of view are pointed out. Introduction Enterobius vermicularis Nematoda, Oxyuridae is a very common parasite, perhaps the most common among the helminths which are enterobbiasis strictly specific for man [ 1 ], even if it has been argued recently that E.
Case 1 A year-old nomadic Yugoslavian woman without enterobiasid fixed abode, was referred urgently to Voghera Hospital Northern Italy in January for oiuriasis acute abdomen. Open in a separate window. Case 2 A year-old man, living in the country near Modena, was admitted to Vignola Hospital Modena, Northern Italy in March for perianal swelling which had been present for about a year but which had become highly painful about three weeks before, in particular while defecating. Discussion In the first case, it would seem, therefore, that the worm had gone back up the genitals and, after penetrating the thickness of the tubal wall which had probably already enterobiaeis damaged by other infective agents, it was halted by the defensive reaction of the host tissues and remained among the inflammatory cells.
Acknowledgment The authors would like to thank the Mrs. American Journal of Diseases of Children. Fatal infection with human pinworm, Enterobius vermicularisin a captive chimpanzee.
Journal of Medical Primatology. Growth of Enterobius vermicularis in a chimpanzee after anthelmintic treatment. Effects of repeated anthelmintic treatment on Oxiurissis vermicularis infection enetrobiasis chimpanzees. Human enterobiasis in evolution: Parasitological survey on pygmies in Central Africa.
Bambuti group Zaire Rivista de Parassitologia. Parasitological oxiurizsis on the Eskimos in the Kotzebue area of Alaska. The Journal of Parasitology.
A newly discovered mode of infection with Enterobius vermicularis. Nematode Parasites of Vertebrates: Their Development and Transmission. Sopra una cisti impiantata sulla salpinge contenente uova di Oxyuris vermicularis. Archives of Medical Science. Ovarian enterobiasis—a proposed pathogenesis. American Journal of Tropical Medicine and Hygiene. Enterobius vermicularis threadworm infestation of paraovarian tissue in a woman who has had a hysterectomy. British Journal of Obstetrics and Gynaecology.
Des tumeurs vermineuses chez les enfants.