Anguillulose

The anguillulose or strongyloïdose is a human Parasitose caused by a Nématode (round worm) tiny, Strongyloides stercoralis whose females Parthénogénétique S parasites, deeply fixed in the mucous membrane duodénale, determine the disease. There exist other worms of the group Strongyloides in particular Strongyloides fülleborni , which infects the Chimpanzé S and the Babouin S and can cause infections limited at the man.

Cycle parasite

The parthenogenetic female saw deeply inserted in the duodéno-jejunal mucous membrane. Not hematophagus, it lays, in the mucous membrane, of eggs resembling those of the ankylostome, but long 50 microns only, Morulé S as of the laying, and which evolve/move very quickly on the spot. At the beginning of the larvae (rhabditoïdes) which leave there, 3 evolutionary cycles are possible:

a sexué indirect cycle ( long cycle );
a parthenogenetic direct cycle ( short cycle );
an endogenous hyper-infectious cycle ( cycle of car-infestation ).

Thus the parasitic cycle of Strongyloïde (or Anguillule) is more complex than that of the majority of the nematodes with its alternation between free life and parasitic cycles, and its potential of autoinfestation and multiplication inside the organization of the Hôte (biology). There exist two types of cycles:

a free life cycle : The Larve rhabditoïde eliminated in the saddles can change twice in the external medium to become an infesting larva strongyloïde (direct development) or to change four times to give rise to males and to adult females (adult stercoraux) which couple and produce eggs from which are resulting from the larvae rhabditoïdes (known as of second generation). The last alternative can lead to a new generation of adults sexués, or with infesting larvae strongyloïdes. The larvae strongyloïdes penetrate through the Peau of the human host to start the parasitic cycle.

parasitic Cycle : The larvae filariformes which live in the ground contaminated penetrate the human skin, and are transported by blood way in the middle right then migrate in the Poumon S where they penetrate the air cells; they go up the bronchioles, the Bronche S, the trachea to the aéro-digestive crossroads (Pharynx where they are swallowed, then they reach the Duodénum after having crossed the Pylore. In the intestine they moult twice to become adult females known as parthenogenetic (in the form it parasitizes does not exist male adult worm); The females live deeply enchased in the mucous membrane duodénale (but they are not hematophagous contrary to the Ankylostome). Their esophagus has only one bulge (form strongyloïde). After Parthénogénèse they lay eggs, which hatch in the intestine to give rise to larvae known as rabditoïdes (because their esophagus has a double bulge). The larvae rabditoïdes (known as of first generation) can be eliminated in the saddles (see “the free life cycle” above), or can enter the internal cycle of autoreinfestation. It is about a cycle runs in which the larvae of rhabditoïdes change into directly into larvae strongyloïdes infesting in the intestine, without passing by again by the external medium. They can penetrate the intestinal mucous membrane (internal autoinfestation) or the skin of the area anopérinéale or the abdomen (external autoinfestation); in one or the other case, the larvae strongyloïdes follows the route previously described, and gains successively the lungs, the bronchial tree, the pharynx, and the duodenum where they become adult (hyperinfestations at the immunodéprimés subjects). In certain cases they can be disseminated largely in all the organization. Up to now, the possibility of a autoinfestation at the man by helminths is known only in the infestations by Strongyloides stercoralis and Capillaria philippinensis . In the case of the Strongyloidose , the autoinfestation can explain the possibility of persistent infestations during many years (up to 30 years) at the people who do not remain any more in endemic zone for a long time whereas the females have one lifespan which does not exceed three months.

Geographical distribution and importance

The disease prevails primarily in the tropical and subtropical areas, but of the cases also occur in the moderate areas (including the south of the the United States), where it is more frequently met in the rural areas, in institutions and in underprivileged socio-economic groups. The disease in the moderate zones is due to carriers coming from the zones of traditional endémie.

Often benign , it does not pose any less, sometimes, a difficult medical problem , and by its resistance to therapeutic, and the existence, at the subjects debilities, of the hyper-infectious cycle; this last, indeed, without free stage of life and external réinfestations, involves an increase increasing in the rate of the parasites by internal car-infestation, with generalization and fatal outcome.

Morphology

The anguillule parasite of the intestine is a tiny parthenogenetic female strongyloïde, very thin and long from 2 to 3 Misters Of other forms adult, male and female stercoraux (which relate to the excrements) exist only in a free state; they are rhabditoïdes and reach 1 mm for the female, a little less for the male.

Clinical characteristics

Noncomplicated Strongyloïdose

Frequently Asymptomatic .

The gastro-intestinal Symptôme S that one can meet are abdominal pains and Diarrhée.

The symptoms Pulmonaire S in particular including the Syndrome of Löffler can occur during the pulmonary migration of the larvae strongyloïdes.

The dermatological demonstrations are presented in the form of eruption of Urticaire in the area of the buttocks and the size.

A éosinophilie Sang uine is generally present.

The strongyloïdose can become chronic and be completely asymptomatic.

Diffuse Strongyloïdose

This form develops among immunodéprimés patients, reached chronic strongyloïdose.

The disease appears by abdominal pains, pulmonary, neurological, abdominal complications and a state of shock, it is potentially mortal. The éosinophilie is often present but not always.

This diffuse form can be declared decades after the initial infection. One quoted the case of an English veteran of the second world war which presented a strongyloïdose diffuses after having received a high amount of corticosteroids, for a Greffe of body. One also observed cases among patients reached of the AIDS, Lèpre, of tertiary Syphilis, medullary Aplasie, advanced Malnutrition, Tuberculose or after Irradiation. It is recommended to seek a chronic strongyloïdose among patients who must receive a immunosuppressor treatment; however in practice this research is often impracticable (the tests serologic are not always available) and in the developed countries, the prevalence of the chronic strongyloïdose is very weak, also systematic tracking is generally not it profitable, except in zones of Endémie.

Private clinic

Although close to the ankylostomose on the biological level, the anguillulose is different from it clearly in its clinical translation:

the period of infestation , whether it is trans-cutaneous or trans-mucous membrane, is seldom individualized;
the period of invasion leads only exceptionally to a Syndrome of notable Löffler, and, only, a éosinophilie with multiple peaks represents the larval migrations successive trans-organics;
the period of state is dominated by the digestive disorders. There is no table of anemia: parthenogenetic females not being neither hematophagous nor toxigenic.

The intestinal signs are very marked; they sign the duodénite and perished-duodénite: violent painful crises, during 3 to 4 days, evolving/moving recurringly every 3 weeks; prolonged diarrheal crises, with type enteritic or colitic, alternating with long phases of constipation; crises urticariennes generalized or located with the areas périnéales and fessiaires.

In the massive infestations of the hyper-infectious cycles, usually announced by the observation of " larva currens" périnéales radiant around the anus, it is not rare that disorders of the assimilation appear, a major deterioration of the general state, then a state cachectic opening to the door with the intercurrent affections quickly mortals. Formerly the prerogative of the subjects debilities and dénutris, this anguillulose malignant can, nowadays, complicate a banal anguillulose at a subject subjected to the Corticoïde S or the Immuno-depressor S.

Diagnosis

association with the ankylostomose frequently makes the diagnosis difficult . It is very difficult to distinguish the larvae from ankylostome of the larvae strongyloïdes. Any diarrhea with the long course, evolving/moving by successive crises, with éosinophilie will order the parasitologic confirmation by tests of laboratory. The Diagnostic rests on the identification with the Microscope of the larvae (rhabditoïdes and sometimes strongyloïdes) in the saddles or the liquid duodénal. The examination of the taking away is necessary, but not always sufficient, because the direct examination of the saddles is relatively not very sensitive.

The saddles can be examined under the microscope:

directly
after concentration
after the recovery of the larvae by the technique of Baermann
after culture by the technique of filter paper of Harada-Mori
after culture on gélose of Agar.

The farming techniques are more sensitive, but are not always achievable in practice current. The direct examination must be made on the saddles coldly collected, which did not have time to cool, because the larvae of ankylostome enkystent themselves when the temperature drops.

The fluid duodénal can be analyzed by using techniques such as the aspiration duodénale. Larvae can also be detected in the Expectoration S among patients reached of strongyloïdose diffuses .

Treatment

The drug of reference for the treatment of the noncomplicated strongyloïdose is the Ivermectine. There also exists of other effective molecules, the Albendazole and the Thiabendazole (with the amount of 25 mg/kg twice a day during 5 days). All the patients who present a risk of strongyloïdose diffuse should be treated. In this possibility, the optimal duration of the treatment is not clearly established.

Individual disease prevention

The wearing of ankle boots, especially in the muddy areas, as well as the immediate and vigorous cleaning and drying of the skin, in the event of contact with mud, are enough to prevent the transmission. It is the same for the ankylostomose.

External bonds

Course anguillulose

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