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Strongyloidosis: an overview
Last reviewed: 23.04.2024
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Strongyloidosis (Latin strongyloidosis) is a helminthiosis from the group of intestinal nematodes, caused by Strongiloides stercoralis and proceeds with allergic reactions, and later with dyspeptic disorders. A person becomes infected by penetration of larvae through the skin or by ingesting them with food.
ICD-10 codes
- Q78. Strongyloidosis.
- B78.0. Intestinal strongyloidiasis.
- B78.1. Cutaneous strongyloidiasis.
- B78.7. Disseminated strongyloidiasis.
- B78.0. Strongyloidosis, unspecified.
Epidemiology of strongyloidiasis
Man is the main source of environmental contamination. The infection of a person in most cases occurs as a result of active penetration of the larvae through the skin when it comes in contact with the infected soil (percutaneous pathway). However, other ways of infection are possible: alimentary (with the use of vegetables and fruits contaminated by helminth larvae), water (when drinking water from contaminated sources of water supply). Cases of occupational infection are described in case of violation of safety regulations in laboratories during parasitological studies of faeces of patients. In strongyloidosis, intestinal self-infection and sexual transmission of infection (in homosexuals) are also possible.
Infection usually occurs in the spring, summer and autumn. Helminthiasis is more often recorded in rural areas, as strongyloidosis is attributed to individuals who are in contact with the soil by occupation. In addition, the risk group includes laboratory assistants of parasitological laboratories, persons in drug treatment units, psychiatric clinics and boarding schools for the mentally retarded.
Strongyloidosis is recorded everywhere due to intensive importation from endemic territories - countries of the tropical and subtropical belt (between 45 ° north latitude and 30 ° south latitude). In the temperate climatic zone sporadic cases are observed. The highest level of population hit in the CIS countries is in Moldova, Ukraine, Azerbaijan, Georgia.
[What causes strongyloidiasis?
Strongyloidosis causes Strongyloides stercoralis (small intestinal nematode), refers to the type Nemathelminthes, the class Nematoda, the order Rhabditida, the family Strongyloididae. In the development cycle of S. Stercoralis, the following stages are distinguished: a free-living and parasitic mature specimen, an egg, a rhabditoid larva, a filarial larva (invasive stage). Development takes place without an intermediate host.
Sexually mature parasitic females 2.2 mm long and 0.03-0.04 mm wide have a colorless filiform body tapering toward the anterior end and a conical tail. Free-living females are somewhat smaller: 1 mm long and about 0.06 mm wide. Male free-living and parasitic have the same dimensions (0.07 mm in length and 0.04-0.05 mm in width).
Pathogenesis of strongyloidiasis
In the early stage, pathological changes in tissues and organs along the migration routes of larvae are caused by sensitization of the body with products of helminth metabolism and their mechanical action. Parasitization of females and larvae causes an inflammatory reaction in the GI tract. During migration, larvae can enter the liver, lungs, kidneys and other organs and tissues where granulomas develop, dystrophic changes and microabscesses. When immunodeficient conditions caused by long-term use of glucocorticoids or cytostatics, HIV infection, hyperinvasia and disseminirovanny strongiloidosis occur. S. Stercoralis parasitize the host for many years. A perennial asymptomatic course of intestinal invasion, capable of quickly reactivating when suppressing cellular immunity, is possible.
What are the symptoms of strongyloidiasis?
The duration of the incubation period of strongyloidiasis is not established.
Strangyloidosis is divided into acute (early migratory) and chronic stages. In most cases, the early migration stage has no symptoms. In the manifest cases in this period strongyloidosis is dominated by the symptom complex of acute infectious-allergic disease. When percutaneous infection in the place of introduction of larvae, erythematous and maculopapular eruptions occur, accompanied by itching. Patients complain of general weakness, irritability, dizziness and headache.
How is strongyloidiasis diagnosed?
Strongyloidosis is diagnosed by the detection of S. Stercoralis larvae in feces or in duodenal contents using special methods (the Berman method, its modifications, etc.). With massive invasion, the larvae can be found in the native smear of feces. When the process is generalized, the helminth larvae can be detected in sputum, in urine.
Additional instrumental studies (radiographic examination of the lungs, ultrasound, EGDS with biopsy of the stomach and duodenal mucosa) are performed according to clinical indications.
What do need to examine?
What tests are needed?
How is strongyloidosis treated?
Strongyloidosis is treated with antihelminthic drugs. Means of choice - albendazole, carbendacim, Alternative medicine - mebendazole.
- Albendazole is prescribed in a daily dose of 400-800 mg (for children over 2 years of 10 mg / kg per day) in 1-2 doses for 3 days, with intensive infestation - up to 5 days.
- Carbendacim is recommended by mouth at a dose of 10 mg / kg per day for 3-5 days.
- Mebendazole is shown inside after a meal of 10 mg / kg per day in 3 doses for 3-5 days.
What is the prognosis of strongyloidiasis?
Strongiloidov has a favorable prognosis in uncomplicated cases when performing etiotropic therapy in the early stages of the disease. With severe current, especially taking place against the background of immunodeficiency, the prognosis is serious.