Serological and molecular tests for the diagnosis of Strongyloides stercoralis infection in dogs

Strongyloides stercoralis can cause severe infection both in humans and dogs. Coproparasitological examination has low sensitivity for the diagnosis of this parasite; hence, different diagnostic techniques have been implemented. However, serology and molecular methods have been assessed almost exclusively in humans. In this study, two serologic assays and a real-time PCR (RT-PCR), routinely used for the diagnosis of strongyloidiasis in humans, have been tested for the diagnosis in dogs. Five dogs living in the same kennel in Bari, southern Italy, were diagnosed with S. stercoralis infection by detection of larvae in fecal samples processed by the Baermann method. Serum, fecal, and tissue (lungs, scraping of intestinal tract) samples from the same dogs were tested with two serologic assays (commercial ELISA, in-house IFAT) and with an in-house RT-PCR, routinely used for diagnosis in humans. IFAT was positive in all serum samples, ELISA in 3/7 (42.8%) samples. RT-PCR was positive in all pre-treatment fecal samples, in all fecal debris, and in intestinal scraping (three samples from the same deceased dog). The results suggest that IFAT and RT-PCR techniques routinely used for S. stercoralis diagnosis in humans could be useful for the diagnosis of the infection in dogs.