The finding of worms in the stool is a rather revolting event, but certainly not uncommon. In fact, it is estimated that helminths (as these parasites are scientifically called) infect about three billion people in the world. The most common in our latitudes are undoubtedly the worms of children (Enterobius vermicularis), also called pinworms, whose prevalence in pediatric age ranges between 30 and 70%. Children are more susceptible to this infestation both for the immaturity of the defense systems and for the habit of playing with mud and putting their hands to their mouths without washing them. In this infestation, the worms in the stool appear as tiny, white, filiform, mobile strips. The females, in fact, measure on average from eight to thirteen millimeters (0.8 - 1.3 cm), while the males - smaller - do not exceed 5 mm. Beyond the macroscopic examination of the faeces, the presence of pinworms can be evidenced by a strong nocturnal itch in the anal and perianal region; the females, in fact, migrate from the intestine to this site to lay their eggs. The consequent scratching and the habit of putting the hands to the mouth, as you can easily guess, favor the self-infestation.
Analyzing a person's stool, however disgusting it may seem, can help reveal the presence of intestinal worms. Not always, however, as in the case of pinworms, the parasites are large enough to be easily identified with the naked eye. On the other hand, when the size of the worms becomes important the scenario becomes even more disgusting. The helminths, in fact, have very variable dimensions and in some cases they are well over one meter in length. This is the case of the tapeworm, a segmented flatworm (cestode ), which can reach 8-9 meters. Generally, in this case, not so much the whole worm is found in the faeces, but some on the white-yellowish segments, similar to pieces of tagliatelle and defined proglottids. The associated symptoms may be absent or limited to nausea, alvus disorders and abdominal pain. The main vehicle of transmission is represented by the ingestion of raw or undercooked meats infected by the larvae.
Duodenal ancylostoma (hookworm)
examined in electron microscopy
scanning.
Other sizable worms, called roundworms (Ascaris lumbricoides), determine the most frequent geohelminthiasis in our country. In the rest of the world, too, ascariasis is a ubiquitous and rather widespread infestation. The term geoelmentiasis explains the modes of transmission of these organisms; briefly, man eliminates the eggs in the soil, where they become embryonated and acquire the ability to infest other humans. The eggs, therefore, are not immediately infesting like those of pinworms, but must spend some time in the ground to "mature". The lack of sanitation or the use of black water to irrigate the fields contribute to the spread of the infestation, typical - but not exclusive - of rural areas. Ascaris lumbricoides reach a length of 40 cm for a weight of about 9 grams. In addition to the visual finding of these cream-white or pinkish worms in the faeces, ascariasis can be characterized by symptoms of a respiratory or gastrointestinal nature (depending on the development stage of the specimens). The first to appear - on the occasion of the migration of the larvae through the lungs - are the respiratory ones, with an irritating cough, dyspnea and traces of blood in the sputum. In the intestine, however, the symptoms are often specific or limited, characterized by abdominal cramps, nausea and vomiting. Especially in developing countries, ascariasis can cause potentially serious, if not life-threatening, complications.
Other common intestinal worms are the "Duodenal ancylostoma and the Necator americanus, responsible for hookworms. It is always a geohelminthiasis, in which however the larvae - instead of being ingested - penetrate through the skin that comes into contact with the contaminated soil. These nematodes, slightly curved, reach a length of 6-12 mm ( 0,6 - 1,2 cm). Thanks to the particular buccal apparatus, they are firmly anchored to the duoedeno-jejunal mucosa, absorbing considerable quantities of blood.The patient, therefore, can become anemic, manifesting pallor, weakness, dyspnoea and brittle nails.
In triocephalosis, the parasite (Trichuris trichiura) reaches a length of 3-5 cm and resembles a whip, with the cephalic end thin and cylindrical, and the posterior one squat and pink.
The finding of a worm in the stool is certainly not a pleasant experience, but the repercussions on the health of the victim are generally mild. Much worse, for example, to be infected with very small organisms, such as some viruses or bacteria. Once the parasite has been identified, moreover, it is generally possible to eradicate it easily, resorting to a short drug therapy. Prevention is essentially aimed at respecting the elementary hygiene rules, such as careful and frequent hand cleaning, careful washing of foods to be eaten raw and generous cooking of meats (in particular minced pork) Particular caution when going to underdeveloped countries (also pay attention to walking barefoot and where one takes a bath).
