User:Gibungeri

Strongyloides stercoralis. This is a human pathogenic parasitic roundworm causing a disease called strongyloidiasis.

PATHOLOGY: S.stercoralis has very low prevalence in areas where fecal contamination of the soil and water is minimal. It can be found in tropics and subtropics.

LIFE CYCLE: S.stercoralis has two typical life cycles; the parasitic cycle which is homogonic that occurs inside the host and the free living cycle which is heterogonic that occurs in the soil.

In the free living cycle, the rhabditiform larvae passed in the stool can either molt twice into infective flariform larvae (direct development) or moult four times and become free living adult males and females that mate and produce eggs from which rhabditiform larvae hatch. The hatched rhabditiform larvae can either develop into a new generation of free living adults or develop into infective flariform larvae. The flariform larvae penetrate the human skin to initiate the parasitic cycle. Some of them enter the superficial veins and are carried in the blood to the lungs, they enter the alvepki. They are then coughed up and swallowed into the gut where they parasitize the intestinal mucosa. In the small intestine, they molt twice and become adult female worms. The female strongyloides reproduce through parthenogenesis. The eggs hatch in the intestine and young larvae are then excreted in the feces. In either case the rhabditiform larvae become infective flariform larvae that may penetrate the intestinal mucosa or perianal surface back to the veins and follow the previous route being carried successively to the lungs, the bronchial tree, throat, and the small intestine where they mature into adults.

Through this they cause autoinfection the host's body.

MORPHOLOGY: Males grow to only about 0.9mm in length and the females can grow from 2.0-2.5mm. Both sexes possess a tiny buccal capsule and cylindrical esophagus. Males and females can be distinguished by two structers; the spicules and gubernaculum.

SYMPTOMS: Dermatitis, swelling, itching, larva currens and mild hemorrhage at the site where the skin has been penetrated. Spontaneous scratch like lesions maybe seen on the face. The chest may feel as if burning and wheezing and coughing may result alongside pneumonia like symptoms if S.stercoralis reaches the lungs. Burning pain, tissue damage, sepsis and ulcers in the intestine. Smelly yellow mucous feces. Chronic diarrhea. Obstruction of intestinal tract and loss of peristaltic contractions.

DIAGNOSIS: Locating juvenile larvae (rhabditiform or flariform) in stool samples will confirm the presence of parasite. Techniques used are: Direct fecal smear, culturing fecal samples, serodiagnosis through ELISA and duodenal fumigation.

PREVENTION AND TREATMENT. Proper disposal of feces. Washing of hands. Treat with drugs like ivermectin(very effective), albendazole, mebendazole and piperazine.