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Strongyloidiasis remains endemic throughout the Island of New Guinea. While many infections are caused by Strongyloides stercoralis, a second human-infecting Strongyloides species, Strongyloides fuelleborni kellyi, is also present. S. f. kellyi infections are most common in infants and young children, and those with high-intensity infections might develop a potentially fatal protein-losing enteropathy, swollen belly syndrome. Surprisingly little work has been performed on S. f. kellyi. Unlike S. stercoralis, S. f. kellyi is passed in faeces as eggs rather than rhabditiform larvae. There is no specific diagnostic test. This review summarises what is currently known about the biology, epidemiology, and clinical impact of S. f. kellyi infections. Features that might be used to differentiate S. f. kellyi from hookworm and S. stercoralis are also discussed. S. f. kellyi remains a neglected, ignored, and unexplored human helminth infection, worthy of further research.

Strongyloidiasis is chronic parasite infection caused by Strongyloides stercoralis . It is endemic in tropical and subtropical areas (1,2). Skin contact with dirty soil and poor sanitary conditions are risk factors for infection. Rhabditiform larvae in warm and moist soil can develop into filariform larvae that can penetrate human skin and migrate through circulation to lungs (3). These larvae escape to alveolar space and migrate to pharynx. By being swallowed in pharyngeal secretion, larvae can settle in small intestine and mature into adults.

Chronic strongyloidiasis is an infection of the tropical regions, caused by the nematode Strongyloides stercoralis. In the United States, patients are typically immigrants. The very long asymptomatic phase followed by the clinical presentation of the disease mimics asthma, chronic obstructive pulmonary disease (COPD), or inflammatory bowel disease (IBD) as in this case report. The inconsistency of eosinophilia and the low sensitivity of microscopic stool examination make chronic strongyloidiasis a disease that is frequently misdiagnosed in the United States. The use of corticosteroids in these misdiagnosed cases transforms chronic strongyloidiasis into disseminated strongyloidiasis or hyperacute syndrome, which leads to high mortality. Iatrogenic errors represent the essential cause of mortality due to chronic strongyloidiasis in the United States. We recommend a high index of suspicion of chronic strongyloidiasis when a physician approaches an immigrant presenting with symptoms mimicking asthma, COPD, and IBD with subcutaneous masses.

Out of 239 samples, 119(49.79%) were positive for parasitic stages, the highest percentage of contamination was detected in leek (64.17%) followed by celery (51.61%), cress (48.1%), lettuce 11(33.33%), and Green onion (32%). The results show that vegetables were positive for different species of parasites; the most prevalent were the cysts of Entamoeba histolytica (14.66%), Rhabditiform larvae (12.44%), ova of Ascaris lumbricoides (12%), Entamoeba coli (12%), Taenia spp. (10%), while the lowest prevalent were ova of Ancylostoma spp. (0.88%), Oesophagostomum spp. (0.88%), and Protostrongylus spp. (0.44%). There was significant difference between prevalence of parasitic organisms among the vegetables.

We report the rare finding of Strongyloides stercoralis rhabditiform larvae in biliary fluid, here associated with cholecystitis and near total portal vein thrombosis. The role of S. stercoralis leading to atypical clinical presentations and difficulty diagnosing strongyloidiasis in such patients with appropriate geographic exposure is discussed.

The course ofStrongyloides stercoralisinfection is usually asymptomatic with a low discharge of rhabditoid larva in feces. However, the deleterious effects of alcohol consumption seem to enhance the susceptibility to infection, as shown by a fivefold higher strongyloidiasis frequency in alcoholics than in nonalcoholics. Moreover, the association betweenS. stercoralisinfection and alcoholism presents a risk for hyperinfection and severe strongyloidiasis. There are several possible mechanisms for the disruption of the host-parasite equilibrium in ethanol-addicted patients with chronic strongyloidiasis. One explanation is that chronic ethanol intake stimulates the hypothalamic-pituitary-adrenal (HPA) axis to produce excessive levels of endogenous cortisol, which in turn can lead to a deficiency in type 2 T helper cells (Th2) protective response, and also to mimic the parasite hormone ecdysone, which promotes the transformation of rhabditiform larvae to filariform larvae, leading to autoinfection. Therefore, when untreated, alcoholic patients are continuously infected by this autoinfection mechanism. Thus, the early diagnosis of strongyloidiasis and treatment can prevent serious forms of hyperinfection in ethanol abusers.

Introduction: Cancer patients are susceptible to severe parasitic infections particularly Strongyloides stercoralis (S.s) infection. Accordingly, this study aimed to determine the prevalence of parasitic infections with highlighting Strongyloides stercoralis infections in 139 cancer patients admitted to oncology ward of Imam Khomeini hospital of Sari during 2009. Material and Methods: In this descriptive and cross-sectional study, fecal samples (n=139) were collected from different cancer patients. After completing the questionnaires, the samples were examined by direct smear and formalin ether sedimentation methods. Results: In this study, of 139 patients with different types of cancer 53.9 % (n=75) and 46.1% (n=64) were male and female, respectively. In the stool exam, two cases (1.4%) infected with Rhabditiform larvae of S.s were detected while both of them were affected with Multiple Myeloma cancer. Conclusion: This study showed that in endemic areas, three times stool examination by formalin-ether technique for detecting Strongyloides stercoralis must be requested before chemotherapy in cancer patients.

Answer: Disseminated strongyloidiasis presenting with larva migrans or cutaneous strongyloidiasis. A repeated stool examination for ova and parasites revealed a few typical rhabditiform larvae (not shown); examination of a fresh sputum smear revealed no larvae. On hospital day 6, the patient

Dispersion or dilution of stool by water from heavy rainfall may affect Strongyloides stercoralis free-living development producing infective filariform larvae (FL). This study examined effect of water dilution of stool on survival of S. stercoralis free-living development. One g of stool was prepared in water so that its soluble component was diluted sequentially from 1:2 to 1:480. Three dishes were used to compare FL production in three culture conditions: stool suspension, stool sediment deposited in soil and isolated rhabditiform larvae (RhL) deposited in soil. The fourth dish was for developmental observation of RhL into free-living stages. Numerous FL were generated from undiluted or 1:2 diluted stool and stool sediment placed on soil. However, starting from dilution 1:5, FL production continuously decreased in both stool suspensions and stool sediments placed on soil. RhL isolated from stool dilutions placed on soil gave rise to few FL. Worm mating were seen at 24-30 hours in dilutions 1:20-1:120 only. Highest numbers of FL from indirect free-living cycle were 1/3 of those from control. FL production decreased as stool dilution increased and reached zero production at 1:160 dilution. Rainfall may disperse or dilute stool so that nutritional supplement for S. stercoralis free-living development is insufficient.

Strongyloides stercoralis, nemátode intestinal de alta prevalencia en zonas tropicales y subtropicales, se presenta clínicamente de forma asintomática u oligosintomática en personas inmunocompetentes. No obstante, la diseminación o hiperinfección por este parásito, puede producir severas complicaciones, a veces fatales en pacientes inmunosuprimidos. Este reporte describe a un paciente masculino de 53 años, trasplantado renal, cuyas complicaciones coinciden con la detección de larvas en las heces. La terapia inmunosupresora usual no impidió el desarrollo de nefritis aguda en este paciente. Los métodos de Baermann y cultivo en agar resultaron positivos en tres muestras consecutivas. Adicionalmente, en el sedimento urinario, se encontraron larvas rabditoides. Posterior al tratamiento con ivermectina la función renal evidenció significativa mejoría. El caso presentado enfatiza la necesidad de investigar la infección por S. stercoralis en los protocolos pre-trasplante en donantes y receptores, y en las complicaciones post-trasplante asociadas con eosinofilia, especialmente cuando proceden del trópico.

Hepatobiliary manifestations of strongyloidiasis are rare. A case is described of biliary obstruction associated with the presence of Strongyloides stercoralis in the duodenal mucosa and 250 microns rhabditiform larvae in bile. Biliary obstruction resulted from papillary stenosis, which resolved after treatment with thiabendazole. It is proposed that papillary stenosis may be responsible for obstructive jaundice associated with Strongyloides stercoralis infection, and that strongyloidiasis should be added to the causes of papillary stenosis.

Strongyloidiasis has been recognized as one of the life-threatening parasitic infections in the immunocompromised patients. We report an intestinal infection case of Strongyloides stercoralis in a 61-year-old man. Rhabditiform larvae were detected in the stool examination and developed to filariform larvae having a notched tail through the Harada-Mori filter paper culture. The patient received five courses of albendazole therapy but not cured of strongyloidiasis.

This study was undertaken to define the precise anatomical location of S. stercoralis in the intestinal mucosa of the dog. In order to facilitate finding worms, hyperinfection was induced by immunosuppression of the host with prednisolone. Light microscopy showed adult worms in vacuoles in close relationship with the columnar epithelium although portions of worms were sometimes seen in the intestinal lumen. Electron microscopy demonstrated that adult worms were situated between the enterocytes. The enterocytes were compressed and distorted and appeared to form a tunnel through which the worm probably moved. Adult worms were never observed to penetrate the basement lamina and enter the lamina propria. Rhabditiform and filariform larvae were never seen in the mucosa. These data suggest that autoinfection does not occur by rhabditiform larvae being seeded directly into the tissues, but supports the hypothesis that they are deposited in the small bowel lumen, moult, then penetrate the mucosa of the lower gastrointestinal tract. Since adult worms dwell in the epithelial layer of the mucosa, they are susceptible to attack by cellular elements of the host's defences, although this was not observed in the present study because the host was immunosuppressed.

SUMMARYThe effects of duration of infection and of temperature and nourishment in cultures on development of free-living generations of Strongyloides stercoralis were studied quantitatively. Rhabditiform larvae, 228–353 μm long, were collected from infected dogs with or without prednisolone treatment using the Baermann apparatus. Cultures were carried out by the filter paper test-tube method under the following conditions: incubation temperature 15–40°C and faecal dilution 1:0–1:16. Rhabditiform larvae developed predominantly to free-living females at incubation temperatures of 15–30°C and low faecal dilutions, but filariform larvae appeared mainly under extreme conditions such as high temperature. Recovery rates of filariform larvae were inversely related to those of females. It was remarkable that high temperature, but not low faecal dilution, affected development of filariform larvae. Although the appearance of free-living males was constant in various environmental conditions, the present study indicated an increase in free-living males with the duration of infection. Thus, it seems that free-living males are already fixed as male in the egg stage, and potential female rhabditiform larvae differentiate into free-living females or filariform larvae depending on environmental factors. There is no marked difference in the development of rhabditiform larvae into filariform larvae in either the immunosuppressed dog or the intact dog.

Rhabditiform larvae of Rhabditis (Pelodera) strongyloides caused pruritic lesions in an 11-year-old girl, and persisted for 2 1/2 months. Larvae were found in skin scrapings from the child and in the family dog's hair.

Among 10,072 examinations of concentrated stools, Strongyloides stercoralis rhabditiform larvae were found in 93, and filariform larvae in four. In two of the four cases harboring filariform larvae, subsequent stools revealed only rhabditiform larvae, but filariform larvae continued to be found in the stools and sputum of the other two cases. It was concluded that only two of the cases were true autoinfections, and the other two apparent cases resulted from prolonged storage of unrefrigerated stools in the hospital ward. The importance of distinguishing true autoinfections from a free-living Strongyloides life cycle in stools is stressed.

Dawkins H. J. S. and Grove D. I. 1981 Kinetics of primary and secondary infections with Strongyloides ratti in mice. International journal for Parasitology 11 : 89–96. The kinetics of infection with S. ratti were quantitated in normal and previously exposed C57B1 /6 mice. In primary infections, larvae penetrated the skin rapidly and were seen in peak numbers 12 h after infection. By 24 h after infection, larval numbers had declined appreciably and there was a slow decrease in numbers thereafter. Larvae were first observed in the lungs at 24 h and maximal recovery occurred at 48 h. It is thought that larval migration through the lungs is rapid. Worms were first seen in the intestines two days after infection. Maximum numbers were seen on the fifth day and worm expulsion was complete by day 10. Two moults took place in the small intestine during days 3 and 4 after infection. Rhabditiform larvae were first noted on the fourth day after infection. Mice exposed to S. ratti four weeks previously had significantly less larvae in the skin 4 and 12 h after infection but by 24 h there was no difference when compared with mice with primary infections. Peak recovery of larvae from the lungs occurred 24 h after infection; significantly less larvae were recovered on days 2 and 3 when compared with normal mice. There was a marked reduction in the adult worm burden in the gut; the number of worms recovered was less than one fifth of that seen in primary infections. Those worms which did mature were less fecund and were expelled from the intestines within 7 days of infection. It is suggested that in previously exposed animals, the migration of larvae from the skin is hastened, many of these larvae are destroyed in the lungs and that expulsion of worms which do mature in the intestines is accelerated.

Rhabditiform larvae, and in two cases eggs, of Strongyloides spp. identified in the stools of Zambian patients were cultured to the free-living adult stage. Free-living adults of S. fulleborni, a parasite common in primates in Africa and Asia, were present in cultures from 13 (9.9%) of 131 cases of strongyloidiasis. In three of these cases, both S. fulleborni and S. stercoralis free-living adults were found.

Bronchoalveolar lavage was performed on a patient with disseminated strongyloidiasis and 4.5 × 10 7 cells/65 ml of lavage fluid were recovered. Eighty-five percent of cells were polymorphonuclear leukocytes; 15 percent were pulmonary alveolar macrophages. Rhabditiform larvae (1 × 10 4 ) were recovered in 65 ml of lavage fluid. This is the first report of bronchoalveolar lavage used in diagnosing disseminated strongyloidiasis. (Chest 1988; 94:643-44)