A Review of Strongyloides spp. Environmental Sources Worldwide

Abstract

Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are capable of causing disease. These nematodes affect an estimated 3–300 million humans worldwide. Identifying the environmental reservoirs of Strongyloides spp. is essential for the development of appropriate control strategies. This systematic literature review examined all published studies that identified Strongyloides stercoralis, Strongyloides fuelleborni, Strongyloides fuelleborni kellyi, and Strongyloides spp. from an environmental source. Most studies detected the nematode from dog and primate fecal samples. Other environmental sources identified were ruminants, cats, rodents, insects, water, soil, as well as fruit and vegetables. Most studies used microscopy-based identification techniques; however, several employed molecular-based techniques, which have become increasingly popular for the detection of Strongyloides spp. A limitation identified was a lack of studies that comprehensively screened all potential environmental samples in a region. Future research should undertake this holistic screening process to identify which environmental reservoirs pose the greatest significance to human health. Potential controls can be identified through the identification of environmental sources. Understanding where Strongyloides spp. is commonly found within the environment of endemic areas will inform environmental control strategies to reduce this neglected disease.

Pathologic characteristics of infectious diseases in macaque monkeys used in biomedical and toxicologic studies

“…The number of eggs per gram (EPG) of feces indicates the severity of infestation 160 , 162 , 163 . Molecular techniques have also been used to identify infectious species 164 , 165 .…”

Factors associated with the presence of helminth eggs in the soil of public areas in Concepción, Chile

“…Some have focused on domestic environments, either considering dogs visiting a veterinary clinic (Ferreira et al, 2016;Tamponi et al, 2017) or analyzing the presence of parasites in dog feces within the domicile (Acosta-Jamett et al, 2014;Quilodrán-González et al, 2018). Others have analyzed the presence of zoonotic parasites in public areas (Sprenger et al, 2014;Medina-Pinto et al, 2018;White et al, 2019), where many have reported parasite findings of high diversity or frequency (Sprenger et al, 2014;Ferreira et al, 2016); still, others have reported not finding any parasites at all (Melín-Coloma et al, 2016). Interpreting the level of risk in these studies is not easy to accomplish given the differences in the design and laboratory techniques used, which can yield different results (Collender et al, 2015).…”

Advances in the Molecular and Cellular Biology of Strongyloides spp.

“…Strongyloidiasis, caused mainly by Strongyloides stercoralis, is one of the most neglected soil-borne tropical diseases. Human infections with Strongyloides fuelleborni and S. fuelleborni kellyi have also been reported in Asia, Papua New Guinea, and some African locales [1][2][3][4][5]. Globally, S. stercoralis is reported to infect more than 370 million people mainly in tropical and subtropical regions [6].…”

“…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].…”

“…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]. S. stercoralis iL3s in the external environment generally infect the host by skin penetration (percutaneous route) [1], but in addition, transmammary transmission has been observed in lactating bitches [13,14].…”