Strongyloides spp. in cats: a review of the literature and the first report of zoonotic Strongyloides stercoralis in colonic epithelial nodular hyperplasia in cats

Abstract

Background Four species of Strongyloides , Strongyloides felis , Strongyloides planiceps , Strongyloides stercoralis and Strongyloides tumefaciens , have been identified in cats based on morphology and location in the host with limited data on the prevalence and disease potential of these different species. Strongyloides tumefaciens adults are located in colonic nodules while the other three species are in the small intestine. The literature on Strongyloides in cats is scattered and has never been compiled. The aim of this article is to provide a short review of the existing literature on Strongyloides spp. in cats, to describe the pathology of colonic nodules containing Strongyloides sp. seen at necropsies of cats in St. Kitts, West Indies, and to provide the first unequivocal report of zoonotic S. stercoralis in cats based on sequencing analysis of a portion of the cytochrome c oxidase subunit 1 ( cox 1) gene, and supported by phylogenetic analysis. Results Colonic nodules containing sections of nematodes, histologically compatible with Strongyloides sp. were seen during necropsy in six cats in St. Kitts, West Indies. Sequencing of the cox 1 gene of the mitochondrial DNA extracted from colonic nodules from two of these cats matched sequences of the zoonotic strain of S. stercoralis. Conclusions The morphological similarities between S. stercoralis- associated colonic nodules and previous reports of S. tumefaciens , together with the insufficient defining criteria for S. tumefaciens raises questions about the validity of the species. Further sampling and genetic characterization of isolates is needed to understand the species in cats and their zoonotic potential.

Pearsonema spp. (Family Capillariidae, Order Enoplida) Infection in Domestic Carnivores in Central–Northern Italy and in a Red Fox Population from Central Italy

“…and, more in general, of nematodes in a cat urinary sample. On the contrary, the presence of nematode larvae in urine samples of dogs and humans has been previously reported, especially in cases of disseminated Strongyloides stercoralis infections [43,44], which is a nematode species that can affect also the cat [45]. The larger width of the nematode fragment found in the positive cat allowed its differentiation from S. stercoralis adults and larvae [12].…”

Machine learning-based analyses support the existence of species complexes for Strongyloides fuelleborni and Strongyloides stercoralis

“…infecting cats is a more complex question, and it appears multiple species are involved, including S. stercoralis. Chandler first reported S. stercoralis in cats in India (Chandler, 1925), and some attempts to infect cats with S. stercoralis from dogs and humans have been successful; though infections were usually short-lived, and it appears that cats are competent but abnormal hosts for S. stercoralis (Sandground, 1928; Desportes, 1944; Wulcan et al ., 2019). Strongyloides felis has been described from India and Australia, and is somewhat similar morphologically to S. stercoralis although no molecular data are available (Speare and Tinsley, 1986).…”

“…These sequences were assigned to genetic cluster 4 in this study (Fig. 2), suggesting that S. tumefaciens infections could simply be an unusual pathological presentation of S. stercoralis (Wulcan et al ., 2019). There is clearly a need for further investigation into Strongyloides spp.…”

“…Even today, the epidemiology of canine strongyloidiasis remains poorly understood, and strongyloidiasis is generally considered a rare disease of dogs outside of East and Southeast Asia and the USA (Kreis, 1932; Galliard, 1951 a ). Reports of S. stercoralis or S. stercoralis -like species in domestic cats further complicates the question surrounding possible zoonotic reservoirs and Strongyloides species diversity (Chandler, 1925; Thamsborg et al ., 2017; Wulcan et al ., 2019).…”

Advances in the Molecular and Cellular Biology of Strongyloides spp.

“…S. stercoralis infections have also been described in dogs, cats, and several nonhuman primates [2,[9][10][11][12]. The prevalence of S. stercoralis in dogs ranges from 0 to over 45%, with younger dogs and puppies more likely to be infected and to exhibit serious or fatal illness [2].…”