How does the parasite enter the body?
Eel larvae live in warm, moist soil, especially contaminated with feces. They penetrate through intact skin, most often through the feet, and an itching and reddish streak may appear at the site of penetration. With the blood flow, the larvae reach the lungs, make their way into the alveoli and rise through the respiratory tract to the pharynx, from where they are swallowed. In the small intestine, females lay eggs, from which larvae emerge. Some of them come out with feces, and some turn into an invasive form right in the intestine and are again introduced into its wall or the skin around the anus.
- Penetration of larvae through the skin of the feet
- Walking barefoot on wet ground, working in the fields and gardens
- Migration through the lungs with cough and throat irritation
- Self-infection within the body without new contact with soil
- Possible persistence of invasion for decades
Symptoms
Many infected people have no complaints for years, and the parasite is found by chance based on elevated eosinophils in the blood. With obvious invasion, pain in the upper abdomen, bloating, alternating diarrhea and constipation, and nausea are disturbing. Skin manifestations are typical: an itchy rash and rapidly moving stripes on the abdomen, buttocks and thighs, which can move several centimeters in an hour. Pulmonary symptoms include dry cough, wheezing, sometimes reminiscent of asthma. The combination of intestinal, skin and pulmonary complaints with high eosinophils is a reason for a targeted examination.
- Pain in the upper abdomen, bloating, rumbling
- Alternating loose stools and constipation
- Nausea, loss of appetite, weight loss
- Itchy, moving, streak-like rash
- Dry cough, shortness of breath, wheezing
- Urticaria and allergic manifestations
- Persistent increase in eosinophils in blood tests
Why is hyperinfection dangerous?
As long as the immune system is functioning normally, the number of parasites is contained. If a person starts taking glucocorticoids, undergoes chemotherapy, receives treatment after a transplant, or has severe immunodeficiency, self-infection becomes out of control. The number of larvae grows like an avalanche, they spread to the lungs, liver, brain and introduce intestinal bacteria into the blood. Severe pneumonia and sepsis develop. That is why in the regions of distribution, before starting hormonal and antitumor therapy, doctors try to exclude strongyloidiasis.
- Taking systemic glucocorticoids is the main provoking factor
- Chemotherapy and immunosuppression after transplantation
- Severe pneumonia and respiratory failure
- Bacterial sepsis and meningitis
- Intestinal obstruction and bleeding
- High mortality without timely treatment
Diagnostics
A routine stool test for helminth eggs in strongyloidiasis is often negative because the larvae are excreted inconsistently and in small quantities. Therefore, the study is repeated several times and special enrichment methods are used, about which the laboratory must be warned. Serological tests for antibodies are additionally helpful. In a general blood test, eosinophilia is typical, and total IgE is often elevated, although with hyperinfection, eosinophils may, on the contrary, be low. In cases of pulmonary symptoms, larvae are sometimes found in the sputum.
- Repeated examination of feces for larvae using special methods
- Serological antibody test
- Complete clinical blood test with eosinophils
- Total IgE
- Cough sputum analysis
- Duodenal contents or endoscopy as indicated
- Examination before prescribing hormones and chemotherapy
Treatment and prevention
Treatment is carried out with a specific antiparasitic drug, which is selected by the doctor; drugs that are effective for other helminthiases work less well for acne. Due to the potential for self-infection, monitoring is required after the course: repeated stool tests and assessment of eosinophil levels after several weeks and months. In case of hyperinfection, treatment is carried out in a hospital and the course is extended. If hormone therapy or chemotherapy is to be performed, the issue of examination and preventive treatment is decided before it begins, and not after the appearance of complications.
- Antiparasitic drug strictly as prescribed by the doctor
- Control tests of stool and eosinophils after the course
- Inpatient treatment for hyperinfection
- Examination before starting hormonal and antitumor therapy
- Do not walk barefoot on wet ground, wear closed shoes
- Gloves when working with soil
- Hand washing, boiled water, washing vegetables and herbs