Clinical signs, treatment, and outcome for California sea lions (Zalophus californianus) with Sarcocystis-associated polyphasic rhabdomyositis.

OBJECTIVE: To describe clinical signs, treatment, and outcome for California sea lions (Zalophus californianus) with Sarcocystis-associated polyphasic rhabdomyositis. ANIMALS: 38 free-ranging juvenile to adult California sea lions examined at a rehabilitation center in California between September 2015 and December 2017. PROCEDURES: Medical records at The Marine Mammal Center were reviewed to identify sea lions in which sarcocystosis had been diagnosed. RESULTS: Clinical signs were highly variable and associated with polyphasic rhabdomyositis attributed to Sarcocystis neurona infection. Generalized severe muscle wasting, respiratory compromise, and regurgitation secondary to megaesophagus were the most profound clinical findings. Respiratory compromise and megaesophagus were associated with a poor prognosis. Eight of the 38 sea lions were treated and released to the wild, and 2 subsequently restranded and were euthanized. Two additional animals received no targeted treatment and were released. The remaining 28 animals were either euthanized or died during treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that unlike other marine mammals, which typically develop encephalitis, California sea lions with sarcocystosis often have polyphasic rhabdomyositis with highly variable clinical signs and that extensive diagnostic testing may be required to confirm the diagnosis. Treatment with an antiprotozoal drug in combination with corticosteroids may resolve clinical disease, but the prognosis is guarded.

Molecular detection of Sarcocystis neurona in cerebrospinal fluid from 210 horses with suspected neurologic disease.

An ante-mortem diagnosis of equine protozoal myeloencephalitis (EPM) is presently based on clinical presentation, immunodiagnostics performed on serum and cerebrospinal fluid (CSF), and ruling out other neurological disorders. Molecular techniques introduce a novel and promising approach for the detection of protozoal agents in CSF. Hypothesizing that real-time PCR (rtPCR) can be a useful complement to EPM diagnostics, 210 CSF samples from horses suspected of neurological disease with EPM included as a differential diagnosis were tested using rtPCR to detect Sarcocystis neurona DNA and immunodiagnostics targeting antibodies against the same pathogen, performed on serum and CSF samples. Molecular and immunological results were compared with respect to origin of the horse, time of the year, signalment, clinical signs and treatment history. Twenty-five horses tested positive in CSF for S. neurona by rtPCR only, while 30 horses had intrathecally-derived antibodies to S. neurona only (serum to CSF ratio ≤ 64 by indirect fluorescent antibody test - IFAT), and 13 horses tested rtPCR-positive in CSF with evidence of intrathecally-derived antibodies to S. neurona. Previous treatment for EPM was the only variable presenting statistical difference between the two testing modalities, highlighting that animals with history of anti-protozoal treatment were more likely to test positive solely in IFAT, while horses without treatment were more likely to test positive by rtPCR only. The results support the use of molecular diagnosis for EPM caused by S. neurona as a complement to immunodiagnostics. The use of rtPCR in CSF for the detection of S. neurona may improve the diagnostic work-up of neurologic disease suspected horses, especially in animals without previous anti-protozoal treatment.

Protozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States.

BACKGROUND: Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. HYPOTHESIS/OBJECTIVES: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. ANIMALS: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. METHODS: Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii, as well as serum and CSF for N. hughesi. RESULTS: Horses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P < .00001), and serum : CSF titer ratio (91.8% versus 0%, P < .00001). Positive results for Neospora and Toxoplasma were uncommon, with total seroprevalence rates of 12.9% and 14.9%, respectively. The proportions of EPM cases testing positive for Neospora and Toxoplasma (16% and 12%) were not different from the proportions of CVSM cases testing positive (10% and 17%, P = .31 and .47, respectively). CONCLUSION: Results do not indicate an important role for protozoal coinfection in EPM in the eastern United States.

Acute fulminant necrotizing myopathy in a dog caused by co-infection with ultrastructural Sarcocystis caninum and Sarcocystis svanai-like apicomplexan protozoa.

Typically, carnivores are the definitive and herbivores the intermediate hosts for protozoan Sarcocystis spp. In the definitive host, the parasite has sexual multiplication in the intestine. Asexual phases occur in the musculature of different intermediate hosts. Although intestinal sarcocystosis is common in dogs, muscular symptomatic sarcocystosis is rarely reported. Here we report a fatal dual Sarcocystis spp. infection in a dog. The dog had acute onset of non-ambulatory tetraparesis. While neurological findings suggested a generalized neuromuscular disease with peripheral neuropathy concordant with the neurological deficits, the highly elevated muscle enzymes were more suggestive of a myopathy. Despite supportive therapy, the dog died three days after the onset of clinical signs. Necropsy revealed severe monophasic multifocal myodegeneration with severe pyogranulomatous inflammation. Histology revealed multiple sarcocysts in skeletal muscles and a smaller number in the heart. In light microscopy, both thin-walled and very thin-walled sarcocysts were found in skeletal muscles. Transmission electron microscopy confirmed the presence of two types of mature sarcocysts. Morphologically, cysts were indistinguishable from Sarcocystis caninum and Sarcocystis svanai, which were previously reported in a dog from USA. A region of the 18S rRNA gene sequence confirmed the presence of one species, S. arctica/caninum, without evidence for a dual infection. This is the first report of muscular sarcocystosis in a dog in Europe and, intriguingly, revealed morphologically similar species across the Atlantic.

Molecular identification of Sarcocystis lutrae in the European otter (Lutra lutra) and the European badger (Meles meles) from the Czech Republic.

Muscular sarcosporidial infections by Sarcocystis lutrae (Apicomplexa: Sarcocystidae) from the otter (Lutra lutra) and badger (Meles meles) (Carnivora: Mustelidae) were found in the Czech Republic. As part of a diversity evaluation of Sarcocystis in wild carnivores during 2016-2017, samples of diaphragm, tongue and hind-limb muscles were collected from nine districts, examined by compression and characterized molecularly. Cyst walls were thin, with no visible protrusions, and histological sections of infected muscle tissue showed no host responses. Fourteen of 17 badgers (82% prevalence) and one otter (100% prevalence) were positive for sarcocysts. Sequence analyses at four loci (18S rRNA, 28S rRNA, ITS1 and cox1) confirmed the identity as S. lutrae. This is also the first report of a co-infection with muscular sarcocystosis and Trichinella in badger. The finding of Trichinella is important from the zoonotic point of view, since badgers are used for meat consumption. Similar and future monitoring of both parasitic taxa are needed.

Unusual Necrotizing Encephalitis in Raccoons and Skunks Concurrently Infected With Canine Distemper Virus and Sarcocystis sp.

Canine distemper virus commonly infects free-ranging, terrestrial mesopredators throughout the United States. Due to the immunosuppressive effects of the virus, concurrent opportunistic infections are also common. Among these, secondary systemic protozoal infections have been described in a number of species. We report an unusual presentation of necrotizing encephalitis associated withSarcocystissp in four raccoons and one skunk concurrently infected with canine distemper virus. Lesions were characterized by variably sized necrotizing cavitations composed of abundant mineral admixed with inflammatory cells and protozoa.Sarcocystissp was confirmed via immunohistochemistry using a monoclonal antibody toSarcocystis neurona The pathologic changes are similar to lesions in human AIDS patients infected withToxoplasma gondii.

Sarcocystis fayeri in skeletal muscle of horses with neuromuscular disease.

Recent reports of Sarcocystis fayeri-induced toxicity in people consuming horse meat warrant investigation on the prevalence and molecular characterization of Sarcocystis spp. infection in horses. Sarcocysts in skeletal muscle of horses have been commonly regarded as an incidental finding. In this study, we investigated the prevalence of sarcocysts in skeletal muscle of horses with neuromuscular disease. Our findings indicated that S. fayeri infection was common in young mature horses with neuromuscular disease and could be associated with myopathic and neurogenic processes. The number of infected muscles and number of sarcocysts per muscle were significantly higher in diseased than in control horses. S. fayeri was predominantly found in low oxidative highly glycolytic myofibers. This pathogen had a high glycolytic metabolism. Common clinical signs of disease included muscle atrophy, weakness with or without apparent muscle pain, gait deficits, and dysphagia in horses with involvement of the tongue and esophagus. Horses with myositis were lethargic, apparently painful, stiff, and reluctant to move. Similar to humans, sarcocystosis and cardiomyopathy can occur in horses. This study did not establish causality but supported a possible association (8.9% of cases) with disease. The assumption of Sarcocysts spp. being an incidental finding in every case might be inaccurate.

Dual congenital transmission of Toxoplasma gondii and Sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (Enhydra lutris nereis).

Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection.

MANAGEMENT OF ACUTE RENAL FAILURE WITH DELAYED HYPERCALCEMIA SECONDARY TO SARCOCYSTIS NEURONA-INDUCED MYOSITIS AND RHABDOMYOLYSIS IN A CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS).

A 3-yr-old captive-born California sea lion (Zalophus californianus) developed Sarcocystis neurona-induced myositis and rhabdomyolysis that led to acute renal failure. The sea lion was successfully managed with fluid therapy, antiprotozoals, antibiotics, anti-inflammatories, antiemetics, gastroprotectants, and diuretics, but developed severe delayed hypercalcemia, a syndrome identified in humans after traumatic or exertion-induced rhabdomyolysis. Treatment with calcitonin was added to the management, and the individual recovered fully. The case emphasizes that animals with rhabdomyolysis-induced renal failure risk developing delayed hypercalcemia, which may be life threatening, and calcium levels should be closely monitored past the resolution of renal failure.

First detection of acalculous cholecystitis associated with Sarcocystis infection in a patient with AIDS.

Acalculous cholecystitis and cholangitis are increasingly being recognized as complications of AIDS. The opportunistic parasites that have been most commonly associated with these disorders are Cryptosporidium species, Isospora belli, Cyclospora cayetanensis and Enterocytozoon bieneusi. The authors performed a parasitological survey on the gallbladder tissue sections of patients underwent cholecystectomy due to chronic acalculous cholecystitis at the Shiraz University of Medical Sciences, Iran. Light microscopic investigation in more than three hundred archived histopathological slides revealed the presence of sexual stages (i.e., mature sporocysts) of a coccidial protozoan in a patient with AIDS who developed acalculous cholecystitis as confirmed by histological, parasitological and molecular tests in which Sarcocystis species was the only identifiable pathogen in gallbladder sections. In the best of our knowledge it's the first documented case of chronic non-calculous cholecystitis due to Sarcocystis parasite in an Iranian AIDS patient from worldwide.

Sarcocystis neurona schizonts-associated encephalitis, chorioretinitis, and myositis in a two-month-old dog simulating toxoplasmosis, and presence of mature sarcocysts in muscles.

Sarcocystis neurona is an unusual species of the genus Sarcocystis. Opossums (Didelphis virginianus, D. albiventris) are the definitive hosts and several other species, including dogs, cats, marine mammals, and horses are intermediate or aberrant hosts. Sarcocysts are not known to form in aberrant hosts. Sarcocystis neurona causes fatal disease in horses (Equine Protozoal Myeloencephalitis, EPM). There are numerous reports of fatal EPM-like infections in other species, usually with central nervous system signs and associated with the schizont stage of S. neurona. Here, we report fatal disseminated S. neurona infection in a nine-week-old golden retriever dog from Mississippi, USA. Protozoal merozoites were identified in smears of the cerebrospinal fluid. Microscopically, lesions and protozoa were identified in eyes, tongue, heart, liver, intestines, nasal turbinates, skeletal muscle and brain, which reacted intensely with S. neurona polyclonal antibodies. Mature sarcocysts were seen in sections of muscles. These sarcocysts were ultrastructurally similar to those of S. neurona from experimentally infected animals. These data suggest that the dog is another intermediate host for S. neurona. Data suggest that the dog was transplacentally infected.

Glomerulopathy in a patient with sarcocystis infestation.

To date, sarcocystis has been considered an asymptomatic infection in humans. Even though cases with glomerulonephritis have been reported in animals with sarcocystis, there have been no reports of a similar occurrence in humans. We report a case of acute proliferative glomerulonephritis and leukocytoclastic vasculitis in a patient with sarcocystis infestation.

[Cardiac involvement in adults with echinococcosis].

Experiments have established that the first target for echinococcus is the liver and lung and that for pathogenic fungi and protozoa is the heart. Adult patients with hepatic hydatid disease complicated by paecilomycosis have been found to have atypical paecilomycosis-associated myocarditis, the treatment of which was developed by the authors, by using antibiotics, fungicides, and homeopathic remedies.

Severe myositis associated with Sarcocystis spp. infection in 2 dogs.

BACKGROUND: Dogs are definitive hosts for numerous species of the intracellular protozoan parasite Sarcocystis. Reports of sarcocysts in muscles of dogs most often represent incidental findings. HYPOTHESIS/OBJECTIVES: To report the clinicopathologic, ultrastructural, and molecular findings in 2 dogs with myositis associated with Sarcocystis spp. infection, as well as the response to treatment with antiprotozoal drugs. ANIMALS: Two dogs with severe myositis in association with massive sarcocystosis. METHODS: Retrospective case review. Affected dogs were identified by a diagnostic laboratory. Attending clinicians were contacted, and the medical records reviewed. Immunostaining and electron microscopy were performed on muscle biopsies. Biopsies also were subjected to 18S rRNA gene PCR. RESULTS: Both dogs had fever, lymphopenia, thrombocytopenia, and increased serum alanine aminotransferase (ALT) activity when first evaluated. One dog developed hyperbilirubinemia. Subsequently, both dogs had increased serum creatine kinase activity and clinical signs of myositis, with reluctance to move, generalized pain, and muscle wasting. Histopathology of muscle biopsies showed severe inflammatory and necrotizing myopathy with numerous sarcocysts. Ultrastructural studies and 18S rRNA gene sequence results were consistent with infection with a Sarcocystis spp. other than Sarcocystis neurona. Both dogs initially were treated unsuccessfully with clindamycin and anti-inflammatory drugs. One dog died. The other dog subsequently responded to treatment with decoquinate. CONCLUSIONS AND CLINICAL IMPORTANCE: Sarcocystis spp. infection should be included in the differential diagnosis for dogs that develop fever, thrombocytopenia, increased liver enzyme activities, and clinical and biochemical evidence of myositis. Although additional studies are required, decoquinate holds promise as an effective treatment for the disease.

Meningoencephalitis associated with Sarcocystis spp. in a free-living Japanese raccoon dog (Nyctereutes procyonoides viverrinus).

A free-living, young adult, male Japanese raccoon dog (Nyctereutes procyonoides viverrinus) was rescued in Gifu, Japan in March 2009. The animal was weak and emaciated with neurological signs that included head tilt, tremor and tic. The brain showed no gross abnormality at necropsy, but microscopically there was severe meningoencephalitis associated with protozoa, which were morphologically consistent with the asexual developmental stage of Sarcocystis spp. The protozoa were immunohistochemically negative for Toxoplasma gondii and Neospora caninum, but reacted weakly with antiserum specific for Sarcocystis cruzi. Analysis of the partial 18S rRNA gene sequence revealed that the protozoa were most closely related to an unidentified Sarcocystis species that was isolated from the white-fronted goose (Anser albifrons).

A novel Sarcocystis-associated encephalitis and myositis in racing pigeons.

Sarcosporidian cysts in the skeletal muscle of domestic pigeons (Columba livia f. domestica) have previously been attributed to infection with Sarcocystis falcatula, which is shed in the faeces of the opossum (Didelphis virginiana). Here, we describe fatal spontaneous encephalitis and myositis associated with Sarcocystis infections in three flocks of racing pigeons with 47 of 244 animals affected. The clinical course was characterized by depression, mild diarrhoea, torticollis, opisthotonus, paralysis and trembling. Histopathological examination of 13 pigeons revealed generalized severe granulomatous and necrotizing meningoencephalitis and myositis with sarcosporidian cysts. Light and transmission electron microscopy identified cysts in heart and skeletal muscle of 1 to 2 mm in length and 20 to 50 microm in width. These were subdivided into small chambers by fine septae and filled with lancet-shaped cystozoites (7.5 x 1.5 microm) and dividing metrocytes, which is characteristic for Sarcocystis. The cysts had smooth walls and were devoid of protrusions typical of S. falcatula. Polymerase chain reaction amplification and sequencing of the internal transcribed spacer region (ITS-1) and the complete 28S rRNA identified a novel Sarcocystis species with only 51% ITS-1 nucleotide sequence similarity with S. falcatula. A phylogenetic comparison of the 28S rRNA revealed close sequence homologies with Frenkelia microti, Frenkelia glareoli and Sarcocystis neurona. The clinical, histopathological, electron microscopic and genetic data are unlike any previously described protozoan infections in pigeons, suggesting a novel, severe disease due to an as yet undescribed Sarcocystis species.

Diagnosis of Sarcocystis cruzi, Neospora caninum, and Toxoplasma gondii infections in cattle.

The aim of the study was to diagnose Sarcocystis sp. infections in cattle and to detect coinfections by Toxoplasma gondii and/or Neospora caninum. Blood, diaphragm, esophagus, and myocardium from 90 beef cattle from Argentina were collected. Histopathological, immunohistochemical, polymerase chain reaction assays, and direct microscopical examination were carried out. Sarcocysts from myocardium were measured and counted. Indirect fluorescent antibody test (IFAT) for the three protozoans was performed. Sarcocystis cruzi sarcocysts were found in 100% of myocardium samples. Sarcocysts per gram ranged from 8 to 380 with higher values found in adult cattle (p < 0.001). T. gondii and N. caninum were not detected by immunohistochemistry. T. gondii DNA was found in myocardium of 2/20 seropositive animals, while N. caninum DNA was not found. Antibodies against S. cruzi were detected in all samples, those against N. caninum in 73% and against T. gondii in 91% of the samples (IFAT titer > or =25). It is concluded that serology by IFAT is a suitable method to diagnose these protozoan infections due to its specific IgG detection; therefore, IFAT may be a useful tool to evaluate the impact of each protozoan infection in coinfected animals.

Sarcocystis and its complications in camels (Camelus dromedarius) of eastern provinces of Iran.

The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area.