Case Report: Incidentally Discovered Strongyloides stercoralis Infection after Urinary Diversion.

Strongyloidiasis is a disease caused by the parasite Strongyloides stercoralis in humans. We present a case of incidentally discovered Strongyloides urinary tract infection in a patient in whom there was a urologic surgery consisting of urinary diversion created by self-bowel transplantation and conduit creation. Historical review demonstrated eosinophilia before surgery and detection of the parasite. Social review demonstrated endemic exposure. Our patient's case was differentiated from hyperinfection by the presence of rhabditiform larvae, and not filariform larvae, in the urine, suggesting localized small bowel infection was transferred to the urinary tract secondary to the creation of the ileal loop conduit. This patient's clinical course improved with antibiotic treatment of the bacterial infectious complications of surgery and resolution of Strongyloides infection with ivermectin. To our knowledge, this is the first case of Strongyloides infection of the urinary tract secondary to ileal loop conduit creation and not as a result of hyperinfection.

Prevalence of strongyloidiasis and schistosomiasis among migrants: a systematic review and meta-analysis.

BACKGROUND: Global migration from regions where strongyloidiasis and schistosomiasis are endemic to non-endemic countries has increased the potential individual and public health effect of these parasitic diseases. We aimed to estimate the prevalence of these infections among migrants to establish which groups are at highest risk and who could benefit from screening. METHODS: We did a systematic review and meta-analysis of strongyloidiasis and schistosomiasis prevalence among migrants born in endemic countries. Original studies that included data for the prevalence of Strongyloides or Schistosoma antibodies in serum or the prevalence of larvae or eggs in stool or urine samples among migrants originating from countries endemic for these parasites and arriving or living in host countries with low endemicity-specifically the USA, Canada, Australia, New Zealand, Israel, and 23 western European countries-were eligible for inclusion. Pooled estimates of the prevalence of strongyloidiasis and schistosomiasis by stool or urine microscopy for larvae or eggs or serum antibodies were calculated with a random-effects model. Heterogeneity was explored by stratification by age, region of origin, migrant class, period of study, and type of serological antigen used. FINDINGS: 88 studies were included. Pooled strongyloidiasis seroprevalence was 12·2% (95% CI 9·0-15·9%; I2 96%) and stool-based prevalence was 1·8% (1·2-2·6%; 98%). Migrants from east Asia and the Pacific (17·3% [95% CI 4·1-37·0]), sub-Saharan Africa (14·6% [7·1-24·2]), and Latin America and the Caribbean (11·4% [7·8-15·7]) had the highest seroprevalence. Pooled schistosomiasis seroprevalence was 18·4% (95% CI 13·1-24·5; I2 97%) and stool-based prevalence was 0·9% (0·2-1·9; 99%). Sub-Saharan African migrants had the highest seroprevalence (24·1·% [95% CI 16·4-32·7]). INTERPRETATION: Strongyloidiasis affects migrants from all global regions, whereas schistosomiasis is focused in specific regions and most common among sub-Saharan African migrants. Serological prevalence estimates were several times higher than stool estimates for both parasites. These data can be used to inform screening decisions for migrants and support the use of serological screening, which is more sensitive and easier than stool testing. FUNDING: None.

Transrenal DNA-based diagnosis of Strongyloides stercoralis (Grassi, 1879) infection: Bayesian latent class modeling of test accuracy.

For epidemiological work with soil transmitted helminths the recommended diagnostic approaches are to examine fecal samples for microscopic evidence of the parasite. In addition to several logistical and processing issues, traditional diagnostic approaches have been shown to lack the sensitivity required to reliably identify patients harboring low-level infections such as those associated with effective mass drug intervention programs. In this context, there is a need to rethink the approaches used for helminth diagnostics. Serological methods are now in use, however these tests are indirect and depend on individual immune responses, exposure patterns and the nature of the antigen. However, it has been demonstrated that cell-free DNA from pathogens and cancers can be readily detected in patient's urine which can be collected in the field, filtered in situ and processed later for analysis. In the work presented here, we employ three diagnostic procedures-stool examination, serology (NIE-ELISA) and PCR-based amplification of parasite transrenal DNA from urine-to determine their relative utility in the diagnosis of S. stercoralis infections from 359 field samples from an endemic area of Argentina. Bayesian Latent Class analysis was used to assess the relative performance of the three diagnostic procedures. The results underscore the low sensitivity of stool examination and support the idea that the use of serology combined with parasite transrenal DNA detection may be a useful strategy for sensitive and specific detection of low-level strongyloidiasis.