Parasitological, Immunological, and Molecular Methods in Diagnosis of Human Strongyloidiasis

Strongyloidiasis is caused by intestinal nematode called Strongyloides stercoralis (S. stercoralis) which can lead to hyperinfection syndrome and disseminated infections. If not diagnosed and properly treated, it can even lead to death. The sensitivity of parasitological methods is not high enough and multiple stool sampling over consecutive days is essential to improve the detection rate. The agar plate culture method is more sensitive to the detection of S. stercoralis in fecal samples than other parasitological techniques. Serological tests have demonstrated higher sensitivity, but they have low specificity because of cross-reactivity with other helminthes. Moreover, they are not helpful for follow-up of treatment, because they cannot distinguish between new and old infections. Recently, some Polymerase Chain Reaction (PCR)-based techniques have been developed for detection of S. stercoralis with high sensitivity and specificity. These methods are rapid but expensive and need well-equipped laboratories. In this paper, conventional and novel methods for laboratory diagnosis of strongyloidiasis are reviewed.