Fatal Sarcocystis cruzi–induced eosinophilic myocarditis in a heifer in Uruguay

Abstract

Sarcocystis spp. are causative agents of bovine eosinophilic myositis and/or myocarditis, which are chronic subclinical myopathies that are occasionally responsible for condemnation at slaughterhouses. Sarcocystis cruzi is a protozoan parasite of worldwide distribution transmitted by canids, most commonly associated with subclinical infection in cattle. Although S. cruzi infections can rarely lead to fatal systemic disease, fatal cardiac cases with confirmation of the etiologic diagnosis have not been reported, to our knowledge. We describe herein an unusual case of S. cruzi–induced fatal bovine eosinophilic myocarditis. A 22-mo-old, Holstein–Hereford heifer, in a group of 110 cattle on pasture, manifested growth retardation and died in February 2017. Autopsy revealed myriad yellow-green 1–3-mm coalescing foci, surrounded by fibrosis, affecting ~75% of the ventricular myocardium. Pulmonary edema, ascites, and hydrothorax were consistent with chronic congestive heart failure. Histology revealed severe eosinophilic, granulomatous, necrotizing myocarditis, with multinucleate giant cells, fibrosis, and mineralization. Numerous thin-walled protozoan cysts resembling Sarcocystis spp. were present in the necrotic foci and within the sarcoplasm of adjacent cardiomyocytes. PCR and sequencing of the 18S rRNA gene revealed 99.9–100% homology with S. cruzi. Sarcocystosis can be a rare cause of fatal myocarditis in cattle.

Sarcocystis infection in red deer (Cervus elaphus) with eosinophilic myositis/fasciitis in Switzerland and involvement of red foxes (Vulpes vulpes) and hunting dogs in the transmission

“…Besides, a genetical predisposition of some individual animals was also suggested to play a role in the pathogenesis of eosinophilic myositis ( Herd et al, 2015 ; Granstrom et al, 1989 ). This hypothesis would be in agreement with the low prevalence of eosinophilic myositis despite the high prevalence of Sarcocystis infection in certain animal species like cattle ( Aráoz et al, 2019 ; Vangeel et al, 2013 ). Observation of damaged intralesional sarcocysts in histologic sections has been an argument in favour of the role of these parasites in the pathogenesis of eosinophilic myopathy ( Vangeel et al, 2013 ; Gajadhar and Marquardt, 1992 ; Wouda et al, 2006 ).…”

“…Several studies provided evidence for a causal association between Sarcocystis spp. infection and eosinophilic myositis in different animal species such as cattle ( Gajadhar et al, 1987 ; Wouda et al, 2006 ; Aráoz et al, 2019 ; Jensen et al, 1986 ; Vangeel et al, 2013 ), sheep ( Jensen et al, 1986 ), horses ( Herd et al, 2015 ) and alpacas ( La Perle et al, 1999 ), including the experimental reproduction of the lesions in cattle ( Vangeel et al, 2012 ). However, the details of the pathological mechanisms of sarcosporidiosis causing eosinophilic myositis/fasciitis and grey-greenish tissue discolouration are mostly unknown.…”

“…Even though the Sarcocystis species found in red deer are not regarded as zoonotic, the affected carcasses can be declared as unfit for human consumption due to the extensive pathological changes ( Stephan et al, 2012 ). Association of Sarcocystis infection with greenish discolouration of the carcasses due to eosinophilic myositis/fasciitis has been described in several animal species including cattle, sheep, horses and South American camelids ( Gajadhar et al, 1987 ; Wouda et al, 2006 ; Aráoz et al, 2019 ; Jensen et al, 1986 ; Vangeel et al, 2013 ; Herd et al, 2015 ; La Perle et al, 1999 ), but this was considered infrequent in cervids ( Stephan et al, 2012 ).…”

Sarcocystis spp. in Romanian Slaughtered Cattle: Molecular Characterization and Epidemiological Significance of the Findings

“…For instance, S. cruzi appears to be able to cause abortions that are clinically indistinguishable from those caused by Neospora and differentiation depends on immunohistochemistry or PCR [25]. In addition, S. cruzi is strongly suspected to be implicated in cases of fulminant death [2, 26], as well as in cases of eosinophilic myositis in cattle [7].…”

“…Naturally, infections occurring in cattle have been occasionally associated with eosinophilic myositis [5, 6], fatal eosinophilic myocarditis [7], and economic losses (e.g., reduced milk production, abortion, or neonatal mortality). The infected intermediate hosts can harbor thin-walled ( S. cruzi and S. heydorni ), and/or thick-walled ( S. hominis , S. hirsuta , and S. rommeli ) muscle sarcocysts, easily differentiable with ultrastructural microscopy [3].…”