This disease arises from a parasite that can inhabit humans and causes itching, irritation and other symptoms.
- You may be interested: “Taeniasis: causes, symptoms and treatment”
Enterobiasis is an exception to this general rule, since the nematode Enterobius is part of the 16% of parasitic pathogens that have evolved to use humans as a source of survival. Due to its specificity and prevalence, it is necessary to understand the mechanisms of infection and treatments for this widespread pathology.
Enterobiasis: a soil-transmitted helminthiasis
Before fully immersing ourselves in the symptoms and treatment of this disease, we see it necessary to briefly frame the causal agent and its global situation.
As we have said before, we are dealing with the Enterobius vermicularis nematode, a worm-shaped parasite of up to 12 millimeters that lives in the colon of infected people. Some of its characteristics are its whitish and opaque color and the presence of three lips in its mouthparts. Due to their size, a microscope is not required to observe them.
Next, we present the life cycle of Enterobius quickly and easily:
- Infection occurs when humans consume the eggs, either by coming into contact with contaminated surfaces or with infested areas of their own body.
- Once ingested, the larvae hatch in the small intestine and settle in the colon (usually in the cecum).
- From the moment of ingestion until the adult female begins to lay eggs, about a month passes.
- Adults survive a couple of months, reproducing and giving rise to offspring.
- The females migrate from the colon to the patient’s perianal area, where they lay eggs that will give rise to new larvae.
Enterobiasis, therefore, is the set of clinical manifestations that the patient experiences during the steps of the life cycle of the parasitetag. As we can see, it is an infection of an obvious nature, since the “worms” are visible and can be seen at night when they lay their eggs.
The importance of helminthiases globally
We cannot continue without making special mention of the socioeconomic importance of soil-transmitted helminthiases (or contaminated matter in general), such as enterobiasis.
According to the World Health Organization (WHO), this type of pathology has various effects on some population sectors :
- Worldwide there are about 1.5 billion people infected by helminths (mainly nematodes) from soils.
- This figure represents almost 27% of the world population.
- More than 500 million children live in populations at risk of transmission of these parasites.
- In infants, these infections have been shown to lead to malnutrition and lack of physical development.
In the case of Enterobius, more than 500 million infestations have been registered globally (42 million in the United States alone) and 50% occur in children (almost 28% of infants worldwide). Therefore, we are facing a parasitic disease with a preference for temperate climates and a clearly affected sector of the population.
Symptoms
Most enterobiasis infections are asymptomatic, but the most common reported symptom is pruritus (itching and irritation) of the perianal area, produced by the inflammatory response that adults , eggs and dead worms generate in the patient’s skin.
This annoying itching has a clear evolutionary significance, as it promotes scratching in the patient, which increases the chances that he will re-ingest the eggs when biting his nails or sucking his fingers. As unpleasant as it may sound, knowing these transmission mechanisms is essential to avoiding the disease in the first place.
Other symptoms, which depend mostly on the parasite load in the host, include insomnia, anorexia, irritability and abdominal distension that produces pain similar to those caused by appendicitis.
Possible complications
Like almost all diseases of a parasitic nature, when causative pathogens proliferate uncontrollably or escape their specific area of action, various medical complications can occur.
Enterobiasis is no exception, since, for example, these nematodes can colonize the genital organs of women, giving rise to pathologies such as vulvovaginitis (genital swelling) or pelvic granulomas, which are spherical masses of immune cells that form when the patient’s immune system tries to isolate a substance that is harmful to the body.
We go further, because depending on the geographical area, up to 40% of cases of appendicitis are correlated with a simultaneous infection by Enterobiustag. Despite the apparently obvious nature of this figure, it has not yet been possible to establish a clear relationship between both clinical processes.
Diagnosis
As rudimentary as it may seem, the use of transparent adhesive tape is often the best diagnostic tooltag. This is adhered to the patient’s perianal area, and subsequently, the elements that have been stuck on it are observed under a microscope.
Being mobile microorganisms of up to 13 millimeters, the females are easily identifiable. In addition, the eggs have a characteristic morphology that allows diagnosis even if no adults are observed. In general, these samples are obtained at night or first thing in the morning, since these periods comprise the moment of maximum oviposition activity of the females.
Contrary to what it may seem, obtaining stool samples to diagnose enterobiasis is not recommended, since eggs and adults do not usually travel in stool.
Treatment
The use of drugs such as mebendazole, pyrantel pamoate or albendazole are the ways to follow in the face of this infection, since all of them are drugs with antiparasitic effects.
These drugs are applied in a single dose, which is followed by another after two weeks. This second administration is necessary to prevent reinfection from occurring due to eggs that have not been eliminated previously and are found in the perianal region of the theoretically already cured patient. It is also recommended that these drugs be administered to all family members or sentimental partners who live with the patient, as they may be asymptomatic carriers of the parasites without knowing it.
Prevention
As you may have already guessed, the best prevention against enterobiasis is sanitation, both of the environment and of the elements for human use. As it is not spread through faeces, the chances of Enterobius being found in contaminated water is low. Some sources that can be infectious are the sheets, clothes and other belongings of an infected person.
For this reason, the Centers for Disease Control and Prevention (CDC) indicate a series of steps to follow in populations at risktag. For example, everyone is advised to thoroughly wash their hands after using the bathroom, changing diapers, and before handling food.
People who are aware of their infectious status are recommended to take a thorough shower every morning, as this encourages the eggs attached to the perianal region to detach from it. All this added to a correct disinfection of the patient’s daily use material (clothes and sheets, for example), should be enough to avoid transmission between people.
Conclusions
We are facing a pathology of parasitic origin that, unlike many others, is more common in temperate geographical areas than in tropical zones. Even so, it shares with other diseases that the risk of infection is greater the lower the sanitation conditions in the general population.
Enterobiasis is in many cases asymptomatic, but its clinical importance should not be underestimated for this reasontag. In children it can cause malnutrition and physical deterioration, and in any case, nobody is attracted to the idea of presenting live worms in their colon.
Bibliographic references
- Arca, M. J., Gates, R. L., Groner, J. I., Hammond, S., & Caniano, D. A. (2004). Clinical manifestations of appendiceal pinworms in children: an institutional experience and a review of the literature. Pediatric surgery international, 20(5), 372-375.
- Enterobiasis, CDC. Retrieved July 26 athttps://www.cdc.gov/dpdx/enterobiasis/index.html
- Soil-transmitted helminth infections, World Health Organization. Collected on July 26 athttps://www.who.int/es/news-room/fact-sheets/detail/soil-transmitted-helminth-infections
- Hugot, J. P., Reinhard, K. J., Gardner, S. L., & Morand, S. (1999). Human enterobiasis in evolution: origin, specificity and transmission. Parasite, 6(3), 201-208.
- Lohiya, G. S., Tan-Figueroa, L., Crinella, F. M., & Lohiya, S. (2000). Epidemiology and control of enterobiasis in a developmental center. Western Journal of Medicine, 172(5), 305.
- Mayers, C. P., & Purvis, R. J. (1970). Manifestations of pinworms. Canadian Medical Association Journal, 103(5), 489.
- Sinniah, B., Leopairut, J., Neafie, R. C., Connor, D. H., & Voge, M. (1991). Enterobiasis: a histopathological study of 259 patients. Annals of Tropical Medicine & Parasitology, 85(6), 625-635.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.
