Epizootic disseminated toxoplasmosis in captive slender-tailed meerkats (Suricata suricatta)

Toxoplasmosis in Human and Animals Around the World. Diagnosis and Perspectives in the One Health Approach

Toxoplasmosis is a unique health disease that significantly affects the health of humans, domestic animals, wildlife and is present in ecosystems, including water, soil and food. Toxoplasma gondii is one of the best-adapted parasites in the word. This parasite is able to persist for long periods in its hosts, in different geographic regions of the word. This review summarizes the current literature of these themes, focusing on: (1) toxoplasmosis, a zoonotic infection; (2) One health approach and toxoplasmosis; (3) human toxoplasmosis; (4) animal toxoplasmosis; (5) toxoplasmosis diagnosis, as immunological, parasitological and molecular diagnosis; (6) T. gondii outbreaks caused by infected meat, milk and dairy products, as well as, vegetables and water consume; (7) studies in experimental models; (8) genetic characterization of T. gondii strains; (9) extracellular vesicles and miRNA; and (10) future perspectives on T. gondii and toxoplasmosis. The vast prevalence of toxoplasmosis in both humans and animals and the dispersion and resistence of T. gondii parasites in environment highlight the importance of the one health approach in diagnostic and control of the disease. Here the different aspects of the one health approach are presented and discussed.

Fatal disseminated toxoplasmosis in a brown-throated sloth (Bradypus variegatus) from Northern Brazil - Case report

The clinical and pathological findings of a case of fatal disseminated toxoplasmosis in a captive brown-throated sloth (Bradypus variegatus) from the northern region of Brazil are reported. Clinical signs were nonspecific and included apathy, prostration, dyspnoea, and loss of appetite. Treatment with penicillin was attempted, but the animal died within five days of the onset of clinical signs. Microscopically, there was acute inflammation in the liver, spleen, and lungs associated with necrosis and a few cysts and extracytoplasmic tachyzoites, with a morphology compatible with Toxoplasma gondii. Tissue sections were submitted for immunohistochemistry that confirmed T. gondii as the aetiological agent. To the authors' knowledge, this is the first report of toxoplasmosis in B. variegatus.

Exposure to Toxoplasma gondii in zoo animals in Spain

A serosurvey was performed to assess exposure to Toxoplasma gondii in zoo animals in Spain and to determine the dynamics of seropositivity in some zoo species over time. Sera from 393 zoo animals belonging to 91 species were collected in eight zoos in Spain between 2007 and 2019. Additionally, 39 of the 393 animals from five of the analyzed zoos were longitudinally sampled during the same study period. Antibodies to T. gondii were detected in 165 (42.0 %; CI95 %: 37.1-46.9) of 393 animals by the modified agglutination test (MAT, cut-off = 25). Antibody titers of 25, 50, 100 and ≥500 were found in 25 (15.2 %), 65 (39.4 %), 26 (15.8 %), and 49 (29.7 %) of the seropositive animals, respectively. Feeding habits (carnivorous species) was a risk factor (OR = 5.6; P < 0.001; CI95 %: 3.8-9.0) potentially associated with T. gondii exposure. Eighteen (46.2 %) of the 39 animals longitudinally sampled were always seropositive and five animals (12.8 %) (two spotted hyaena [Crocuta crocuta], one blesbok [Damaliscus pygargus], one white rhinoceros [Ceratotherium simum] and one mouflon [Ovis aries musimon]) seroconverted during the study period. Our results evince a wide circulation of T. gondii in zoos in Spain, including wild felids. Zoo animals can be useful sentinel species to monitor T. gondii circulation in epidemiological scenarios with a close human-wildlife interface. Control measures should be implemented in zoo parks to minimize the risk of exposure of zoo species to T. gondii.

Procyonidae, Viverridae, Hyenidae, Herpestidae, Eupleridae, and Prionodontidae

This chapter covers the diseases and pathology of multiple taxonomic groups within the order Carnivora including Procyonidae several of the Feliformia carnivores. The overwhelming majority of knowledge about disease pathogenesis for these species is biased toward raccoons and concern for disease spread to humans and companion animals. Procyonids and feliform carnivores are ubiquitous in their environments and share habitat and environmental resources with other nondomestic and domestic carnivores and humans. As reservoirs for a number of important multispecies or zoonotic pathogens, surveys for pathogens that may be harbored or vectored by several of the species in this chapter, for example, raccoons (e.g., canine distemper virus, rabies, and leptospirosis) and civets (e.g., SARS coronavirus), have been active areas of investigation. Unfortunately, less research has focused on the potential effects of these pathogens on their hosts.

Fatal disseminated toxoplasmosis in a zoological collection of meerkats (<i>Suricata suricatta</i>)

Two confirmed cases of fatal disseminated toxoplasmosis occurred in an urban zoological collection of meerkats (Suricata suricatta). Both cases are suspected to be the result of feral cats gaining access to the enclosure. Toxoplasmosis has rarely been documented in meerkats. Subsequent to prophylactic treatment of all the animals and structural changes being implemented within the enclosure, no new cases have been recorded to date. Very little information is available on the disease in viverrids.

Small intestinal inflammation following oral infection with Toxoplasma gondii does not occur exclusively in C57BL/6 mice: review of 70 reports from the literature

Small intestinal immunopathology following oral infection with tissue cysts of Toxoplasma gondii has been described in C57BL/6 mice. Seven days after infection, mice develop severe small intestinal necrosis and succumb to infection. The immunopathology is mediated by local overproduction of Th1-type cytokines, a so-called 'cytokine storm'. The immunopathogenesis of this pathology resembles that of inflammatory bowel disease in humans, i.e., Crohn's disease. In this review, we show that the development of intestinal pathology following oral ingestion of T. gondii is not limited to C57BL/6 mice, but frequently occurs in nature. Using a Pubmed search, we identified 70 publications that report the development of gastrointestinal inflammation following infection with T. gondii in 63 animal species. Of these publications, 53 reports are on accidental ingestion of T. gondii in 49 different animal species and 17 reports are on experimental infections in 19 different animal species. Thus, oral infection with T. gondii appears to cause immunopathology in a large number of animal species in addition to mice. This manuscript reviews the common features of small intestinal immunopathology in the animal kingdom and speculates on consequences of this immunopathology for humankind.

Accuracy of three diagnostic tests for determining Mycobacterium bovis infection status in live-sampled wild meerkats (Suricata suricatta)

Accurate diagnosis of Mycobacterium bovis infection (bovine tuberculosis [bTB]) in live animals is notoriously problematic. The aim of the present study was to evaluate the diagnostic potential of 2 new serologic tests (multiantigen print immunoassay [MAPIA] and lateral flow immunoassay rapid test [RT]) in comparison with mycobacterial culture of tracheal washes for determining M. bovis infection status in a free-ranging population of wild meerkats (Suricata suricatta). During a longitudinal study lasting 2.5 years, 240 individually identifiable meerkats were each sampled up to 8 times under anesthesia every 3 months. Diagnostic accuracy was determined through Bayesian and maximum likelihood estimations of sensitivity, specificity, and likelihood ratios for each diagnostic test when used independently and in parallel to classify the disease status of individual meerkats in the absence of a gold standard. Culture of tracheal washes was highly specific (0.99; 95% confidence interval [CI] = 0.77, 1.00) but of low sensitivity (0.36; 95% CI = 0.24, 0.50) for diagnosing M. bovis-infected individuals. The longitudinal nature of the study with repeated sampling of the same individual animals served simultaneously to improve chances of detecting infection and increase confidence in a negative result in individual animals repeatedly testing negative. Although MAPIA and RT were individually of limited diagnostic use, interpreting the results of these 2 tests in parallel produced estimates of sensitivity (0.83; 95% CI = 0.67, 0.93) and specificity (0.73; 95% CI = 0.62, 0.82) high enough to usefully inform decision making when determining exposure to bTB in wild meerkats and potentially other species in which bTB poses a diagnostic challenge.

Toxoplasmosis in a colony of sugar gliders (Petaurus breviceps)

Eleven of a group of 16 sugar gliders died acutely over a period of 2 to 3 weeks. Histopathologic examination revealed a protozoal infection with tachyzoites present in multiple organs, including the intestine, heart, brain, spleen, pancreas, adrenal gland, and kidney. Immunostaining confirmed disseminated toxoplasmosis. Marsupials are susceptible to toxoplasmosis. It was thought that the sugar gliders acquired the infection through foraging in wood chips used as a substrate that were contaminated with feline fecal material.

Acute disseminated toxoplasmosis in a captive three-toed sloth (Bradypus tridactylus)

Fatal toxoplasmosis was diagnosed in a captive three-toed sloth (Bradypus tridactylus), an arboreal species of the tropical rainforests of South and Central America. In view of its specialized lifestyle and ecosystem and its low metabolic rate, B. tridactylus would seem to warrant further investigation in respect of its susceptibility to Toxoplasma gondii.