Enterobiasis is an infectious disease that affects people worldwide, especially children, caused by pinworm parasite.
This article will discuss the Enterobius parasite, what it does in the body, how it is transmitted, and what symptoms it causes to the patient.
Furthermore, there will be explanations of the possible complications, how it is diagnosed and treated. Continue reading for more information on this common infection, directly from a doctor.
What does enterobiasis mean?
Enterobiasis refers to the infection by the parasite Enterobius vermicularis. Parasites are organisms that live inside or on a host, from which they get their food.
There are two main types of parasites; helminthic and protozoa. The first is multicellular, can be seen with the naked eye in most cases, and have a worm-like shape. The latter are unicellular and are microscopic, unlike the helminthic counterparts.
Both of them have complex life cycles in which they depend on a host for food and reproduction. They also have parts of their life in which they can live without a host, mostly to infect other hosts.
Enterobius vermicularis is a very common helminthic parasite that infects all humans but mostly affects children. It has a thin-round shape, is white-colored, and it is approximately half a centimeter or less. There are a male and a female worm, the male having a spiraled tail and the female a long-thin one. Because of the female’s long thin tail and round body shape, comes its popular name ¨pinworm¨ or ¨threadworm¨.
The parasites go through different stages, taking various forms that are part of their life cycle. There are eggs, embryonated eggs, larvae, and the adult worm.
The adult form resides in the appendix and the first part of the colon. In these, the worms copulate, and then the female pinworm goes to lay the eggs in the anus’s margins.
These eggs later become embryonated eggs, 6 hours after the female pinworm laid them. The embryonated eggs are the ones humans ingest and swallow, leading to them hatching in the small intestine.
They hatch larvae, which are a previous stage to the adult worm, and take two weeks to grow into their final form. Finally, the adult worm stays in the cecum and appendix, in which they can live for approximately two months.
How enterobiasis happens?
The primary way a person can get a threadworm infection is through the ingestion of infective eggs. There are different ways in which a person can ingest the eggs, whether they come from someone else or themselves. The fecal-oral route, in which the eggs go from the anus to the mouth, can be direct or indirect.
The direct route is when the person gets in touch with fecal material coming straightly from the infected individual. For example, this can be by scratching the area with the eggs and then putting their fingers in their mouth. The eggs can stay underneath the fingernails if the hands aren’t clean posteriorly. When the already infected person ingests the pinworm eggs again, this is known as reinfection. Another direct way is through sexual transmission by having oral sex in contact with the anus or perianal area.
The indirect route is by getting in contact with inanimate objects that have the eggs over them. This can happen because of a person with an Enterobius vermicularis infection putting their unclean hands over these objects. It can also occur by placing the object in direct contact with the infected person’s perianal region. Examples of these can be food, towels, underwear, bedsheets, furniture, toilets, and many others. The infection can happen by touching the eggs in these objects and then touching their mouth with unwashed hands. Eggs are light enough for them to float; therefore, it causes the person to inhale them and posteriorly swallow them. This happens in case the eggs are in bedsheets or clothes that a person manipulates constantly.
Some studies say the eggs can hatch in the perianal region and cause a retroinfection. This can happen by larvae reentering the anus, although it is not common.
What does the pinworm do in the body?
The pinworm lives predominantly in the first part of the colon and the very last of the small intestines. In these, they get the nutrients they need to live, and they reproduce as well.
These intestinal parasites live free in the intestines without attaching themselves to the walls most times. When they do attach themselves to the intestinal walls, they can cause small damage to none. In acute infections of E vermicularis, sometimes they can cause diarrhea, although this is not common, even with pinworm infestation.
After effectively copulating with their male counterpart, female pinworms migrate to the rectum. If the person in that period defecates, they go outside of the body with the feces.
If the worm persists in the body, they travel at night time to the margins of the anus. In this area, it introduces a pin it has on its tail to the mucosa to attach. The female can then lay nearly eleven thousand eggs, which takes around 6 hours to become embryonated eggs.
Afterward, these eggs can resist up to three weeks in the environment being infectious. When the female pinworm put the eggs, it finishes its life cycle and dies in the anus margins.
There aren’t particular risk factors for a person to get the parasite inherent to the person’s body functions but to their social conduct. This means there isn’t a disease that can make a person more likely to get the parasite. Although there are mental conditions that can influence people’s conduct, there isn’t a clear link to enterobiasis.
Living with a person who has the parasite actively is the most critical risk factor to be aware of. Others are poor hygiene and living in confined spaces with a large number of people.
What are the symptoms of a pinworm infection?
In most patients with this parasite, the disease can be asymptomatic (without symptoms), and it is discovered by accident. When it is not asymptomatic, the characteristic symptom in people with enterobiasis is perianal pruritus, which basically means itching in the anus margins. This happens because of the laying of the eggs in that region and the movements of the worm.
A vital characteristic this itching possesses is that it occurs at night time when the patient goes to sleep. In small children, this is significant to notice as they might not necessarily know how to express the itchiness. They can appear tired, restless, or irritated, or parents describe their child is not sleeping well.
The anal itching can lead to scratching that may cause redness and irritation in the skin surrounding the anus. There can also be pruritus or itching in the vulva in female patients due to infection of the area with the parasite.
In some pediatric patients, enuresis can happen because of the itchiness while sleeping. This means involuntarily peeing at night in children older than four years old that already had sphincter control. This is not as common, although it shows the different ways the disease can present itself, especially in children.
Some parents get their children to the doctor, not because of the pruritus ani (anal itching), but because of worms. In severe cases, worms may be visible in the perianal folds as tiny white strands. With confirmation by a doctor, this alone is enough to make a diagnosis and send treatment.
There is an association between diarrhea to pinworms in very few cases, and most believe it may be coincidental. Many times when a person has a parasitic infection, there might be other intestinal parasites that cause gastrointestinal symptoms.
What are the complications associated with a pinworm infection or enterobiasis?
Although this is a highly contagious infectious disease and can be hard to treat for different reasons, it isn’t severe. Most of the time, the weightiest thing to happen is the discomfort the patient can suffer due to the itching.
When the patient does undergo some sort of complication, it is an erratic movement to other body parts. One of the commonest is the worm infection of the female genitalia. In some cases, the patient scratches the anal area and can transport the worms or eggs to the vulva. In this, the parasite in any form can cause vulvovaginitis, which is the infection of the vulva and the vagina.
The adult worm can go up through the genital tract of the female, even to a fallopian tube. In this case, the body creates a granuloma, a group of immunological cells, around the pinworm. These appear when the body cannot get rid of an external threat and instead isolates it.
Some studies refer that appendiceal pinworms can cause appendicitis, which is the infection or swelling of the appendix. This would appear as a sudden abdominal pain and fever and needs surgical intervention.
Many other studies say that the appearance of appendicitis with pinworms in the organ is merely coincidental. This makes it still unclear whether a worm infection of this type can cause appendicitis or not.
How do you diagnose enterobiasis or a pinworm infection?
Doctors may suspect that you or your children are suffering from a pinworm infection based on clinical manifestations. The cardinal symptom is itching in the perianal region (in the anus surroundings). The doctor will confirm the diagnosis by identifying the worms or eggs.
Sometimes, patients could see the female helminth near the anus or underwear. This could happen at night when she comes out to lay her eggs. It is rare to observe pinworm in the feces; still, it is possible to see them in patients with a high parasite load.
Physicians recommend performing the Graham test or “tape test” to collect the Enterobius eggs. This test involves pressing the sticky side of a clear cellophane tape against the skin at the margins of the anus.
If there are eggs that adhere to the tape, then doctors can see them under a microscope. They also recommend doing this test when the person just wakes up in the morning. This is to prevent patients from bathing or using the toilet, which could remove the eggs from the skin.
Repeating the test for three consecutive days can increase the chance of detecting parasite eggs; it is even plausible to do it for five days. However, it is not rare for doctors to also order to take samples from under the nails. Less frequently, they can also find eggs in urine or vaginal smears.
What are the treatment options for enterobiasis or a pinworm infection?
The treatment against enterobiasis is the same medication used against helminth infections in general. These can be mebendazole, albendazole, or pyrantel pamoate. Usually, larvae can resist these medications, making the treatment consist of two doses of medication. The second dose comes two weeks after the first one, to terminate any previous larvae that are now an adult.
It is important to give mass medication to the people who constantly surround the patient, such as family members. This is because it is very likely they also got the parasite as it’s highly contagious. The mass medication also helps to reduce the prevalence of the disease. The prevalence is the number of cases a disease has in a certain period in a portion of the population.
How do you break the pinworm cycle?
After receiving treatment, there are some precautions patients should take and make part of their daily routine to avoid reinfection. These are nothing more than simple personal hygiene practices.
First of all, washing their hands with soap and warm water after using the toilet and before eating or cooking. Second, avoiding scratching the anal region and trimming their fingernails regularly. It is essential for them not to bite their fingernails to reduce the chance of picking up pinworm eggs.
Doctors recommend that infected people should take a shower every morning to help to remove the eggs. They also suggest not co-bathe with others while infected as well as not sharing towels.
Changing underwear, towels, and bedding when getting up in the morning would help prevent reinfections. The best way to do this is by carefully placing them in a washing machine and then in a hot dryer. If the above is not possible, patients can also boil water in a large pot and place them into it.
It is important not to shake the bedding to avoid spreading the eggs in the environment. Vacuuming beds and other frequently used areas in the household could also reduce the spreading of the infection. This is because the eggs can remain in the environment for up to 3 weeks and infect someone.
Do you have symptoms of enterobiasis or pinworm infection?
This tool is a Pinworm infection Symptoms Checker. It gathers the most important signs, symptoms, and risk factors for this disease. Therefore, the tool will tell anybody who uses it the likelihood of their symptoms because of enterobiasis or pinworm infection. Using this tool is free and would only take a few minutes.