The severely under‐recognized public health risk of strongyloidiasis in North American cities—A One Health approach

Abstract

Strongyloides and other soil-transmitted helminths represent a severely under-recognized zoonotic public health risk, especially in North American cities. They are present throughout North America, including in urban areas, causing morbidity and mortality in human and non-human animals. Epidemiological "masking" of strongyloidiasis due to overlapping symptoms with other systemic diseases, including allergies, and diagnostic limitations complicate our understanding of the epidemiological extent of this disease, and auto-infection allows long-term persistence of individual infections. Zoonotic transmission and environmental transmission are critical components in the epidemiology of strongyloidiasis, and other diseases caused by soil-transmitted helminths. In this review, we bring together medical, veterinary and environmental expertise in a "One Health" context, to document and analyse this under-recognized risk. We also present implementable opportunities for action with respect to diagnostics, treatment, community engagement and land management to mitigate the impact and transmission of strongyloidiasis and other diseases caused by soil-transmitted helminths.

Prevalence of parasitic infections among recent immigrants to Chicago

“…Serologic tests can have significant limitations as they often have cross-reactivity among multiple parasites and these tests cannot distinguish between prior and current infections. [3, 6, 8, 17, 28, 37, 71, 72]…”

“…Additionally, these tests are frequently unavailable in the community. [4, 6, 7, 17, 25, 28, 29] Serologic testing, the primary method of diagnosis for many parasitic infections, has several important shortcomings, which contributes to the lack of accurate information regarding these infections. These limitations include: an inability to distinguish between active and past infections, the presence of significant crossreactivity between serologic tests for different parasites, and the fact that some infections (such as many stool helminthiases) do not cause a detectable serologic response.…”

Parasitic infections represent a significant health threat among recent immigrants in Chicago

“…Among select populations within the USA, parasitic diseases are thought to be an under-recognized public health problem (Garg et al 2005;Hotez 2007;Hotez 2008;Hotez 2014;Hotez et al 2012;Jariwala et al 2017;Parise et al 2014). Although exact numbers are not available, studies have suggested that within the USA there may be up to 300,000 people with Chagas disease (Bern et al 2011;Bern and Montgomery 2009;Leiby et al 2002;Manne-Goehler et al 2016;Sarkar et al 2010;Schmunis and Yadon 2010;Zaniello et al 2012), 1.3-2.8 million with serological evidence of exposure to Toxocara spp.…”

“…Both diagnostic and methodologic problems have impeded research regarding parasitic infections among US immigrants. Diagnostic inaccuracies can occur because laboratory tests for parasites can have significant limitations including poor sensitivities and lack of availability in the community (Belhassen-Garcia et al 2014;Hotez 2014;Jariwala et al 2017;Ostera and Blum 2016;Parise et al 2014;Posey et al 2007;Shulman et al 1997). Further, the primary method of diagnosis for many parasitic infections, serologic testing, has several important shortcomings, including an inability to distinguish between active and past infections, cross-reactivity between different parasites, and in many cases a reduced sensitivity due to the focal nature of some parasitic diseases (Khurana and Sethi 2017;Maddison 1991;Ndao 2009).…”

“…Many of the published studies evaluating health impacts of parasitic infections on immigrants either screened for only a small number of parasites or screened immigrants from a single country (Bern et al 2011;Bern and Montgomery 2009;Ostera and Blum 2016;Ostera et al 2017;Rapoport et al 2015;Sarkar et al 2010;Won et al 2008;Zaniello et al 2012). Improved data regarding these health impacts is badly needed as parasitic infections can have significant morbidity (Fitzpatrick et al 2010;Hotez 2007;Hotez 2008;Hotez et al 2012;Jariwala et al 2017;Parise et al 2014;Posey et al 2007;Starr and Montgomery 2011). For example, Chagas disease causes cardiomyopathy and/or esophageal or colonic dilation in up to 20-30% of those infected (Bern et al 2011;Moncayo and Ortiz Yanine 2006); those with toxocariasis may have an increased risk for asthma (Buijs et al 1997;Cobzaru et al 2012;Kanobana et al 2013;Walsh 2011); and intestinal parasite infection has been associated with delayed cognitive development and impaired nutrition in some studies (Ezeamama et al 2005;Yap et al 2012).…”