Strongyloides stercoralis

Strongyloides stercoralis
Nematode (nematode)
Strongyloididae
Adult parasite
Occurrence especially in tropical and subtropical areas
Disease strongyloidosis
Infectious stage and method of infection larva (percutaneous)
Diagnostics stool larvae detection, detection of specific antibodies, detection of parasitic DNA, marked eosinophilia and leukocytosis
Therapy Thiabendazole, Albendazole, Mebendazole
MeSH ID 68017171


Strongyloides stercoralis or intestinal nematode is a small worm causing strongyloidosis. It belongs to Nematoda - nematodes. It usually lives in the outdoor environment - in humid tropical, subtropical areas, but also in cold areas. If the larvae encounter a human at the stage, they will attack it.

Life cycle

They are small worms with a size of 0.8–2.2 mm  with a complex evolution. Upon contact with humans, they actively penetrate the skin and enter the bloodstream. They get through the lungs through the blood , where they irritate the airways and force a person to cough. They enter the esophagus through the alveoli, bronchi and trachea . They then settle in the small intestine, where the larvae mature, copulate and begin to produce eggs . Eggs enter the stool or may hatch in the host's digestive tract.

If a person is not immunocompetent enough, the eggs hatch in the GIT and the larvae penetrate the wall into the bloodstream, where they migrate to various tissues.

Clinical signs

The patient's clinical symptoms depend on where the parasite is located.

Skin phase

    • Itching on the skin.
    • Macroscopically visible path.
    • Local edema .

Pulmonary phase

The pulmonary phase usually manifests itself as 6-9. the day after infection .

GIT phase

We already have pathogenic agents in the digestive tract that cause problems. Females settle in Lieberkühn's crypts and produce eggs. Hatched larvae can invade the mucosa again, causing multiple ulcerations and subsequent wall thickening. Clinically, this will manifest itself as:

  • abdominal pain in the epigastrium,
  • diarrhea,
  • bleeding into the GIT.

Hyperinfection syndrome is the result of disseminated strongyloidosis (dissemination of larvae throughout the body, affected liver, heart, lungs, gallbladder and intestines) in immunosuppressed individuals (AIDS). In these people, the disease is severe. Severe diarrhea, ileus and bronchopneumonia are common.

Diagnostics

  • Microscopy: detection of larvae in stool about 27 days to 1 month after infection.
  • Detection of specific antibodies .
  • Detection of parasitic DNA (not performed in the Czech Republic).
  • Laboratory tests: marked eosinophilia and leukocytosis, decrease in values ​​in the chronic phase of infection.

Therapy

  • Albendazole
  • Thiabendazole
  • Ivermectin
  • Levamisole


Source

  • CHANOVÁ, Marta. Diseases caused by nematodes  [lecture on the subject Parasitology, General Medicine, 1st Medical Faculty, Charles University]. Prague. 12/10/2015 

Reference

  1. VOLF, Petr and Petr HORÁK. Parasites and their biology. 1st edition. Prague: Triton, 2007. 318 pp. 209–210. ISBN 978-80-7387-008-9 .
  2. ↑ FÖRSTL, Miroslav, Vladimír BUCHTA and Libuše KOLÁŘOVÁ. Overview of diagnostics and therapy of intestinal parasitosis. Internal medicine for practice. 2004, vol. 6, vol. 4, pp. 209, ISSN 1803-5256. 

References

  • BEDNÁŘ, Marek, A SOUČEK and V FRAŇKOVÁ, et al. MEDICAL MICROBIOLOGY: Bacteriology, virology, parasitology. 1st edition. Triton, 1996. 560 pp.  ISBN 859-4-315-0528-0 .


Parasites
Protozoa (Protozoa)
Amoeboid protozoa
Exchange offices Acanthamoeba spp. • Balamuthia mandrillaris • Naegleria fowleri
Whips
Leishmania Leishmania braziliens • Leishmania donovani • Leishmania infantum • Leishmania major • Leishmania tropica
intestinal parasites Dientamoeba fragilis • Entamoeba histolytica • Giardia intestinalis
Trichomonads Trichomonas vaginalis
Trypanosomes Trypanosoma cruzi • Trypanosoma gambiense • Trypanosoma rhodensiense
Rinning Balantidium coli
Sporozoa
Babesie Babesia bovis • Babesia divergens • Babesia microti
Coccidia Cryptosporidium parvum • Cyclospora cayetanensis • Isospora belli
Microsporidia Enterocytozoon bieneusi • Encephalitozoon spp.
interhost Toxoplasma gondii
Plasmodia Plasmodium falciparum • Plasmodium malariae • Plasmodium ovale • Plasmodium vivax
Helmint
Trematoda (Motolice)
liver and lung mites Clonorchis sinensis • Fasciola hepatica • Opistorchis spp. • Paragonimus spp.
Schistosomes Schistosoma haematobium • Schistosoma japonicum • Schistosoma intercalatum • Schistosoma mansoni • Schistosoma mekongi
intestinal tapeworm Fasciolopsis buski • Heterophyes heterophyes • Metagonimus yokogawai
Nematode (Nematode)
Filaria Brugia malayi • Dirofilaria immitis • Dirofilaria repens • Loa loa • Mansonella perstans • Onchocerca volvulus • Wuchereria bancrofti
intestinal nematodes Ancylostoma duodenale • Ascaris lumbricoides • Enterobius vermicularis • Necator americanus • Strongyloides stercoralis • Trichuris trichuria
tissue nematodes Dracunculus medinensis • Toxocara spp. • Trichinella spiralis
Cestoda (Tasemnice)
intestinal cestodes Diphyllobothrium latum • Dypilidum caninum • Hymenolepis nana • Taenia saginata • Taenia solium
tissue cestodes Echinococcus granulosus • Echinococcus multilocularis • Taenia solium
Arthropods
Insect Anoplura (lice) • Diptera (diptera) • Cimex lectularius • Siphonaptera (fleas)
Spiders Ixodes ricinus • Sarcoptes scabiei
Intracellular parasites
Chlamydia Chlamydia pneumoniae • Chlamydia psittaci • Chlamydia trachomatis
Portal: Microbiology

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