Strongyloidiasis Flashcards by Ezrah Isaac Roy

Strongyloidiasis is caused by what

strongyloides stercoralis

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what is the fourth most important nematode infection in the world

strongyloides stercoralis

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what is the mortality for strongyloides stercoralis

Dissemination in immunocompromised patients and those receiving
corticosteroids (mortality up to 85%)

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what caused diarrhee de la cochinchine

Strongyloides

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what are the names of Strongyloides

Bavay named Anguillula stercoralis and then Anguillula intestinalis

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who established the genus strongyloides

grassi

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who elucidated the life cycle of

Fulleborn (1911), Kreis (1932) and Faust (1933)

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what does S procyonis (raccoon) do

Threadworms, heterogenetic, free-living and parasitic generations, include
at least 40 named species)w

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what is the main strongyloides species

S. stercoralis

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how many people are infected with strongyloides

370 million of people

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where is strongyloides

All tropical and subtropical regions
Europe (Northern Italy, France, Spain, Switzerland, Poland)
USA (Appalachian region, West Virginia)
Japan (Okinawa)
Australia (aboriginal populations)

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explain life cycle strongyloides

-autoinfection
-homogonic cycle
heterogenic cycle

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The first-stage juveniles (J1) often are referred to as

rhabditiform because posterior
end and esophagus separated by a prominent bulb.

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how big is the free living female strongyloides

2-3 mm long
37 um wide

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what is the lenght of free living strongyloides

0.9mm

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why is strongyloides unique

has a free-living life cycle and
an autoinfective cycle in addition to the normal parasitic type life cycle.

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what are the hosts of strongyloides

Natural: Humans
other primates
dogs
cats
Experimentally:
gerbils
Patas monkeys
SCID mice

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reproduction of strongyloides

-Parasitic adults are parthenogenetic.
-Free-living adults are sexual.

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where does the stronfyloides female live

in the small intestibe in the epithelial mucosa and the crypts of liberkuhn

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true or false: in strongyloides, the eggs are embryonated when laid

yeah it is L1

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in strongyloides, which stage is the one in which life history decisions are made

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how big are the strongyloides eggs

(50-58 um by 30-34 um)

what does L1 have in terms of physical things

-esophagus
-genital primodium

what is the autoinfective stage in strongyloides

L3a
has an intestine and a filariform esophagus

autoinfection of strongyloides: triggers

1. Corticosteroids (prednisone) 2. Immunosuppression (tacrolimus) 3. Neonatal infections 4. Infections with transplanted adults 5. Co-infection with Th-1 inducing pathogens 6. Massive initial infections 7. Intestinal stasis

Homogonic (direct) development vs Heterogonic (indirect) development of strongyloides: determinants

1. Immune status of the host 2. Environmental parameters 3. Presence of food

Third stage infective larva (L3i): behavior

1. Positively thermotacic 2. Attracted to salt 3. Increased movement in presence of CO2 4. Attracted to urocanic acid 5. Positively geotactic

Migration starts with a “layover” in the skin for strongyloides

1-2 days

migration from the skin takes how long for strongyloides

4 days

in strongyloides how long does it take for the larva to reach the small intestine

5-6 days

how long does to take for stringyloides to reach l4

4 days

young adults of strongyloides in the intestine at ... days post infection

7 days post infection

to see l1 in feces for strongyloides how long does it take

10-14 days lol

CUTANEOUS MANIFESTATIONS of strongyloides

* Urticarial rashes * Migratory serpiginous dermatitis * Periumbilical cutaneous purpura

pulmonary manifestations of strongyloides

* Diffuse bronchopneumonia * Intra-alveolar hemorrrhage

GI manifestation of strongyloides

* Epigastric abdominal pain * Postprandial fullness * Heartburn * Brief episodes of diarrhea * Malabsorption

diagnostic challenges of strongyloides

-fatal disease in immunocompromised and lifelong autoinfection -intermittent larval excretion -insensitivity of standard lan techniques -insensitivity of our best larva finding technique aka agar plate -no available gold standard test like ag capture, pcr -non specificity of standard strongyloides serologies

true or false: there is. a test recombinant antigen for strongyloides

yeah

20 Canadian children between age 3 and 16 with eosinophilic oesophagitis, how many were seropositive for strongyloides crude antigen

45% -but they never travelled to strongyloides endemic areas -The parents and embarrassingly non-specific serology

Specificity Testing of Strongyloides Recombinant Antigen serology what are the advantages

.. no endemic Strongyloides stercoralis .. Plenty of trichinellosis in Arctic (non-travellers) .. Plenty of other eosinophilic enteridides (eg Eosinophilic esophagitis) .. Some sylvatic hydatids .. Very rare human dirofilariasis

Specificity Testing of Strongyloides Recombinant Antigen serology what are the disadvantages

.. Southern Canada endemic for Strongyloides procyonis (in raccoon) .. Other endemic Canadian helminths include Echinococcus granulosis (sylvatic), Toxocara canis, Baylisascaris procyonis, Diphyllobothrium spp.

TREATMENT for strongyloides

* Ivermectin: 200 ug/kg per day * Thiabendazole: 50 mg/kg per day * Albendazole: 400 mg orally for adults and 15mg/kg per day for children

Transmission of HTLV-1 occurs through

breast feeding, sexual intercourse, transfusion of contaminated blood products or sharing of contaminated syringes and needles.

HTLV-1: Human T-cell-lymphotropic virus (endemic....

in Japan, Africa, the Caribbean and South America

Patients with strongyloidiasis and HTLV-1 co-infection (n = 12) had more......

Strongyloides stercoralis larvae found in stool when compared to strongyloidiasis-only patients

Increased proportions of regulatory T cells in strongyloidiasis/...

HTLV-1 co-infected patients.

...... responses to larval Strongyloides stercoralis antigens are decreased in patients with strongyloidiasis and HTLV-1 co-infection compared to HTLV-1 negative subjects with strongyloidiasis

IL-5

Increased numbers of regulatory T cells correlates with reduced....

IL-5 responses to Strongyloides Stercorarius larval antigens

the hyperinfection is has a high mortality rate of?

15-87%

what are the risk factors for hyperinfection syndrome

-predisposing conditions -htlv-1 infection

which immune response is inhibited caused by hyperinfection syndrome

th2 cell mediated

recommendations for strongyloides

-Immigrant…screening -Investigating peripheral eosinophilia -Chemotherapy Pre-immunosuppression screening -Human T-lymphotropic virus type 1 (HTLV-1) patient -Strongyloides post-treatment follow-up