Hymenolepiasis is a disease caused by the parasite Hymenolepis nana , which can infect children and adults and cause diarrhea, weight loss and abdominal discomfort.
Infection with this parasite is done through the consumption of contaminated food and water, so it is important to adopt some preventive measures, such as washing hands and food before preparing them. See other measures to prevent worms.
The diagnosis of himenolepiasis is made by searching for eggs in the feces and treatment is usually done with the use of antiparasitic agents, such as Praziquantel, for example.
Main symptoms
Symptoms of H. nana infection are rare, but when the person's immune system is weakened or when there are large numbers of parasites in the intestine, some symptoms can be noticed, such as:
- Diarrhea; Abdominal pain; Malnutrition; Weight loss; Lack of appetite; Irritability.
In addition, the presence of the parasite in the intestinal mucosa can lead to the formation of ulcers, which can be quite painful. In rarer cases, hymenolepiasis can lead to the appearance of symptoms related to the nervous system, such as seizures, loss of consciousness and seizure.
The diagnosis is made by examining feces that aims to identify the presence of parasite eggs, which are small, semi-spherical, transparent and surrounded by a thin membrane. Understand how the stool test is done.
How the treatment is done
The treatment of himenolepiasis is done with drugs that normally do not cause side effects, such as Praziquantel and Niclosamide.
Despite being an easy-to-treat parasitosis, it is important that hymenolepiasis is prevented by prophylactic measures to reduce infection by this parasite. Thus, it is important that better hygiene habits are adopted, such as washing hands before eating and after using the bathroom, washing food before preparing them and adopting control measures for insects and rodents, as they can be intermediate hosts of Hymenolepis nana.
Biological cycle
Hymenolepis nana can have two types of biological cycle: the monoxenic, in which there is no intermediate host, and the heteroxenic, in which there is an intermediate host, such as rats and fleas, for example.
- Monoxenic cycle: it is the most common cycle and begins with the accidental ingestion of parasite eggs present in contaminated water or food. Ingested eggs reach the intestine, where they hatch and release the oncosphere, which penetrates the villi of the intestine and develops into a cysticerccoid larva, which attaches to the intestinal mucosa. This larva develops into an adult worm and lays eggs, which are eliminated in the feces, giving rise to a new cycle. Heteroxenic cycle : this cycle occurs from the development of the parasite inside the intestine of the intermediate host, such as rats and fleas, which ingest the eggs released into the environment. The man acquires the infection through the contact with these animals, mainly, or through the consumption of food or water contaminated by the feces of these hosts, initiating the monoxenic cycle.
One of the factors that facilitates infection by this parasite is the short life span of the parasites: adult worms can only survive 14 days in the body and, therefore, they quickly release eggs, which can survive up to 10 days in the external environment, being enough time for a new infection to occur.
In addition, the fact that it is an easy infection to obtain, environments with a high concentration of people, such as daycare centers, schools and prisons, which in addition to having many people together, sanitary conditions are precarious, facilitate the transmission of the parasite.
