Serological evidence of exposition to Toxoplasma gondii in Saimiri spp. kept in a research institution as biomodels in Rio de Janeiro.

Anti-Toxoplasma gondii antibodies were investigated in 125 Saimiri spp. kept at a research institute. A total of 12% of primates tested positive, all of which were Saimiri sciureus. These results highlight the need to minimize the possibility of this protozoan's circulation, which can lead to fulminant infection in these animals.

Diagnostic features of metastatic endometrioid carcinoma in a captive black-tufted marmoset (Callithrix penicillata).

A captive marmoset developed metastatic endometrioid carcinoma (EnC), a rare uterine tumor in non-human primates (NHPs). The neoplasm showed marked microscopical malignant and tubulopapillary aspects, immunopositivity for pan-cytokeratin, CK7, estrogen receptor, and a high mitotic index (Ki-67). These features may contribute to the diagnosis and therapeutics of EnC in NHPs.

Thyroblastoma in a rhesus macaque (Macaca mulatta): A case report.

In this report, we describe the gross, histopathology, and immunohistochemical findings of a thyroblastoma that arose in the right lobe of the thyroid gland in a 2-month-old rhesus macaque (Macaca mulatta).

Lingual neoplasia in nonhuman primates: Description of five cases and a literature review.

BACKGROUND: Documentation of lingual tumors is scarce in nonhuman primates. METHODS: Through a multi-institutional retrospective study we compile cases of primary and metastatic neoplasia in non-human primates. RESULTS: We describe five cases of lingual neoplasia. Three cases are primary lingual tumors: chondro-osteoblastic lipoma in a howler monkey, squamous cell carcinoma, and fibroma in two baboons. We describe two cases of metastatic lymphoma in the tongue in rhesus macaques. A literature review of published lingual neoplasia in nonhuman primates is included in this manuscript. CONCLUSION: Lingual neoplasia is seldom reported in non-human primates.

An exploratory deep learning approach to investigate tuberculosis pathogenesis in nonhuman primate model: Combining automated radiological analysis with clinical and biomarkers data.

BACKGROUND: Tuberculosis (TB) kills approximately 1.6 million people yearly despite the fact anti-TB drugs are generally curative. Therefore, TB-case detection and monitoring of therapy, need a comprehensive approach. Automated radiological analysis, combined with clinical, microbiological, and immunological data, by machine learning (ML), can help achieve it. METHODS: Six rhesus macaques were experimentally inoculated with pathogenic Mycobacterium tuberculosis in the lung. Data, including Computed Tomography (CT), were collected at 0, 2, 4, 8, 12, 16, and 20 weeks. RESULTS: Our ML-based CT analysis (TB-Net) efficiently and accurately analyzed disease progression, performing better than standard deep learning model (LLM OpenAI's CLIP Vi4). TB-Net based results were more consistent than, and confirmed independently by, blinded manual disease scoring by two radiologists and exhibited strong correlations with blood biomarkers, TB-lesion volumes, and disease-signs during disease pathogenesis. CONCLUSION: The proposed approach is valuable in early disease detection, monitoring efficacy of therapy, and clinical decision making.

Simian retrovirus transmission in rhesus macaques.

Historically, to generate Simian Retrovirus (SRV) positive control materials, we performed in vivo passage by inoculating uninfected rhesus macaques with whole blood from an SRV-1 infected (antibody and PCR positive) macaque. However, recent attempts using this approach have failed. This study reports observations and explores why it has become more difficult to transmit SRV via in vivo passage.

Histopathological characterization and grading of chronic enterocolitis in Sulawesi crested macaques (Macaca nigra).

Sulawesi crested macaques (Macaca nigra) (SCMs) are critically endangered and frequently suffer from chronic intestinal disease in captivity. Often, despite routine diagnostic investigations and confirmation of intestinal inflammation, an aetiology cannot be identified, leading to a non-specific categorization as chronic enterocolitis rather than an aetiological diagnosis. This study evaluates the histological features of gastrointestinal tissues from 23 SCMs, comparing animals with a clinical history suggestive of chronic enterocolitis (n = 14) with those without gastrointestinal clinical signs (n = 9). Tissues were graded according to the Nancy index (NI), a scoring system used in human medicine to evaluate disease activity in ulcerative colitis, a common form of human inflammatory bowel disease (IBD). Additionally, inflammatory cells in the colonic lamina propria were visually identified by type, counted and subsequently compared between diseased and control animals. Moderate to severe lymphoplasmacytic inflammation and structural changes were most common in the colons of affected SCMs, whereas histopathological changes were absent or mild in all examined small intestine (n = 17) and stomach (n = 11) tissues. The colonic NI had a significant positive correlation with clinical disease severity and 57% (n = 8) of animals with clinical signs had a NI grade of ≥2, consistent with moderate to severe, active IBD. Half of SCMs with recurrent rectal prolapse (n = 6) had a NI grade of 0, suggesting that intestinal inflammation is not always part of this condition's pathogenesis. The numbers of colonic lymphocytes, plasma cells, neutrophils, macrophages and total leucocytes were significantly higher in diseased animals. This study validated the use of the NI in SCMs, enabling a more standardized histopathological evaluation of the colon in this species.

COVID-19 in a common woolly monkey (Lagothrix lagothricha): First evidence of fatal outcome in a nonhuman primate after natural SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by the World Health Organization in March 2020. Since then, viral spread from humans to animals has occurred worldwide. Nonhuman primates (NHPs) have been found to be susceptible to reverse-zoonosis transmission of SARS-CoV-2, but initial research suggested that platyrrhine primates are less susceptible than catarrhine primates. Here we report the natural SARS-CoV-2 infection of a common woolly monkey (Lagothrix lagothricha) from a wildlife rehabilitation center in Ecuador. The course of the disease, the eventual death of the specimen, and the pathological findings are described. Our results show the susceptibility of a new platyrrhine species to SARS-CoV-2 and provide evidence for the first time of a COVID-19-associated death in a naturally infected NHP. The putative route of transmission from humans, and implications for captive NHPs management, are also discussed. Given that common woolly monkeys are at risk of extinction in Ecuador, further understanding of the potential threat of SARS-CoV-2 to their health should be a conservation priority. A One Health approach is the best way to protect NHPs from a new virus in the same way that we would protect the human population.

DETECTION OF SARS-COV-2 IN A SQUIRREL MONKEY (SAIMIRI SCIUREUS): A ONE HEALTH INVESTIGATION AND RESPONSE.

Through collaborative efforts, One Health partners have responded to outbreaks of COVID-19 among animals, including those in human care at zoos. Zoos have been faced with numerous challenges, including the susceptibility of many mammalian species, and therefore the need to heighten biosecurity measures rapidly. Robust One Health collaborations already exist in Arizona to address endemic and emerging zoonoses, but these have rarely included zoos. The pandemic shed light on this, and Arizona subsequently expanded its SARS-CoV-2 surveillance efforts to include zoo animals. Testing and epidemiologic support was provided to expedite the detection of and response to zoonotic SARS-CoV-2 infection in zoo animals, as well as to understand possible transmission events. Resulting from this program, SARS-CoV-2 was detected from a rectal swab collected from an 8-yr-old squirrel monkey (Saimiri sciureus) from a zoo in Southern Arizona. The animal had rapidly become ill with nonrespiratory symptoms and died in July 2022. Genomic sequencing from the swab revealed mutations consistent with the Omicron (BA.2) lineage. An epidemiologic investigation identified an animal caretaker in close proximity to the affected squirrel monkey who tested positive for COVID-19 the same day the squirrel monkey died. Critical One Health partners provided support to the zoo through engagement of local, state, and federal agencies. Necropsy and pathologic evaluation showed significant necrotizing colitis; the overall clinical and histopathological findings did not implicate SARS-CoV-2 infection alone as a causal or contributing factor in the squirrel monkey's illness and death. This report documents the first identification of SARS-CoV-2 in a squirrel monkey and highlights a successful and timely One Health investigation conducted through multisectoral collaboration.

Gastrointestinal helminths of captive proboscis monkey (Nasalis larvatus) in Surabaya zoo, Indonesia.

BACKGROUND: One of the constrain in proboscis monkey (Nasalis larvatus) conservation is gastrointestinal helminth (GH) infection. Here, we conducted a study to determine the prevalence of GHs in captive proboscis monkeys in Surabaya Zoo, Indonesia. METHODS: Twenty fecal samples were collected from three groups (i.e., nursery cage [NC] [n = 1], communal show cage [SC] [n = 8], and free-ranging colonies [FC] [n = 11]). The fecal samples have been examined through McMaster and sugar floatation techniques. RESULTS: The total prevalence of GH infection was 85.00% (17/20). We confirmed infection of Trichuris sp., Ascaris sp., Strongyloides sp., and Hymenolepis nana with Trichuris eggs was dominant. Although the prevalence of infection was high, the number of eggs per gram (epg) was low. CONCLUSION: GH infection in captive proboscis monkeys in Surabaya Zoo, Indonesia, is highly prevalent. These results were useful for future research, control, and prevention of zoonotic potency purposes.

Natural mycobacterium tuberculosis complex infection in a brown howler monkey (Alouatta guariba clamitans) in Brazil.

Neotropical primates rarely exhibit active tuberculosis. A brown howler monkey was found injured in an urban area. Histopathology revealed granulomatous inflammation in the lungs, lymph nodes, and liver. Immunohistochemistry and molecular analysis confirmed the presence of Mycobacterium tuberculosis complex. The findings highlight the importance of TB surveillance in nonhuman primates.

Contribution of ultrasound examination in diagnosing platynosomiasis and correlation with macro and microscopic findings in callitrichids kept under human care.

BACKGROUND: Platynosomiasis in non-human primates kept under human care causes chronic disease of the bile ducts and liver, which initially presents with nonspecific signs and can culminate in the death of the animal. Diagnosing this disease is a challenge, and an ultrasound examination can be an excellent tool when it is suspected. METHODS: This study describes the ultrasound findings from 57 marmosets with suspected infection by Platynosomum sp., the correlated hepatobiliary changes, and the anatomopathological findings that confirmed the occurrence of platynosomiasis. RESULTS: In six marmosets (one C. aurita, two C. jacchus, and three Callithrix sp.), Platynosomum infection was confirmed macroscopically (presence of adult trematodes in the gallbladder) and microscopically (adults, larvae, and eggs in histological examinations and eggs in bile and feces). These findings were compatible with the hepatobiliary changes and with images suggestive of parasitic structures in ante-mortem assessments. CONCLUSION: Ultrasound examination demonstrated its usefulness within the clinical routine for investigating this parasitosis.

Diversity of gastrointestinal parasites and molecular characterization of Giardia duodenalis in free-living and captive howler monkeys (Alouatta guariba clamitans) in southern Brazil.

Non-human primates (NHPs) are the group that most share infectious agents with humans due to their close taxonomic relationship. The southern brown howler monkeys (Alouatta guariba clamitans) are endemic primates from Brazil and Argentina's Atlantic Forest. This study aimed to investigate the presence of intestinal parasites in free-living (FL) and captive (CA) southern brown howler monkeys. Thirty-nine stool samples were collected in two areas in southern Brazil, 15 FL and 24 CA. Stool sediments obtained by centrifugal sedimentation technique were used for microscopic analysis and direct immunofluorescence assay and evaluated by molecular analysis through amplification and sequencing of TPI fragments. Intestinal parasites Giardia duodenalis, Cryptosporidium spp., and Trypanoxyuris minutus were detected at coproparasitological analysis. This is the first report of the presence of Cryptosporidium spp. in free-living howlers. The molecular characterization of G. duodenalis isolates indicated assemblage B for the first time found in free-living A. guariba clamitans. The high prevalence of G. duodenalis transmission in CA howler monkeys can be explained by direct contact with humans and frequent soil contact. The presence of a potentially zoonotic assemblage in these animals indicates that the process of fragmentation and cohabitation with humans and livestock affects the wildlife, thus indicating a need for eco-health measures.

Oral cavity squamous cell carcinomas in zoo-managed Goeldi's monkeys (Callimico goeldii).

BACKGROUND: Oral cavity squamous cell carcinomas (OCSCCs) are relatively common in multiple non-human primate species but are poorly documented in Goeldi's monkeys. METHODS: Four Goeldi's monkeys with OCSCC, from three zoological collections, underwent necropsy with cytology, histopathology, immunohistochemistry, and pan-herpesvirus PCR analysis. RESULTS: All animals were euthanised and exhibited poor-to-emaciated body condition. Three OCSCCs arose from the maxillary oral mucosa and a single OCSCC was primarily mandibular, with bone invasion evident in three cases. Histologically, one OCSCC in situ was diagnosed, whilst the rest were typically invasive OCSCCs. Neoplastic cells were immunopositive for pancytokeratin and E-cadherin. All examined cases were negative for regional lymph node (RLN) and/or distant metastases, cyclooxygenase-2 (COX-2) immunoexpression, and panherpesvirus PCR expression. CONCLUSIONS: OCSCCs in Goeldi's monkeys may be deeply invasive, but not readily metastatic. No herpesvirus-association or COX-2 expression was evident; the latter suggesting that NSAIDs are unlikely to be a viable chemotherapeutic treatment.

Evaluation of the main disorders and microbiota of the oral cavity of capuchin monkeys (Sapajus apella) under human care.

BACKGROUND: Although critical to the overall condition of animals under human care, there is still limited information about oral health in neotropical primates. METHODS: We analyzed the main oral conditions and microbiota using mass spectrometry from 13 capuchin monkeys (Sapajus apella) under human care. The findings were registered on odontograms following the Triadan system. RESULTS: The most prevalent conditions were dental fractures (n = 9), mainly enamel fractures, and periodontal disease (n = 8), mainly grade 1 calculi. When exanimating teeth, alterations were identified in 90 out of the 416 evaluated pieces, being periodontal disease the most common (n = 60), followed by enamel fracture (n = 15) and missing teeth (n = 10). In the oral microbiota analyses, Staphylococcus and Streptococcus species were the most prevalent, although no obvious association was observed between isolated organisms and oral conditions. CONCLUSIONS: These findings hold the potential to prevent oral disorders, including fractures and periodontal diseases, contribute to molecular identification of oral microbiota, and to improve the well-being of primates under human care.

Real-time fluorescence loop-mediated isothermal amplification assays for detection of zoonotic malaria Plasmodium parasites.

BACKGROUND: Natural human infections by Plasmodium cynomolgi and P. inui have been reported recently and gain the substantial attention from Southeast Asian countries. Zoonotic transmission of non-human malaria parasites to humans from macaque monkeys occurred through the bites of the infected mosquitoes. The objective of this study is to establish real-time fluorescence loop-mediated isothermal amplification (LAMP) assays for the detection of zoonotic malaria parasites by combining real-time fluorescent technology with the isothermal amplification technique. METHODS: By using 18S rRNA as the target gene, the primers for P. cynomolgi, P. coatneyi and P. inui were newly designed in the present study. Four novel real-time fluorescence LAMP assays were developed for the detection of P. cynomolgi, P. coatneyi, P. inui and P. knowlesi. The entire amplification process was completed in 60 min, with the assays performed at 65 °C. By using SYTO-9 as the nucleic acid intercalating dye, the reaction was monitored via real-time fluorescence signal. RESULTS: There was no observed cross-reactivity among the primers from different species. All 70 field-collected monkey samples were successfully amplified by real-time fluorescence LAMP assays. The detection limit for P. cynomolgi, P. coatneyi and P. knowlesi was 5 × 109 copies/µL. Meanwhile, the detection limit of P. inui was 5 × 1010 copies/µL. CONCLUSION: This is the first report of the detection of four zoonotic malaria parasites by real-time fluorescence LAMP approaches. It is an effective, rapid and simple-to-use technique. This presented platform exhibits considerable potential as an alternative detection for zoonotic malaria parasites.

First record of Cebidicola armatus (Phthiraptera: Trichodectidae) on the Brachyteles hypoxanthus (Primate: Atelidae) in Brazil.

This study reports for the first time the infestation of Cebidicola armatus in Brachyteles hypoxanthus. In total, 14 lice were recovered of an individual in Minas Gerais, Brazil. These were subjected to a microscopic analysis and the identification of C. armatus was carried out through its very characteristic morphology.

Golden lion tamarin metapopulation dynamics five years after heavy losses to yellow fever.

The golden lion tamarin (GLT) is an Endangered primate endemic to Brazil's lowland Atlantic Forest. After centuries of deforestation and capture for the pet trade, only a few hundred individuals survived, all in isolated forest fragments 85 km from Rio de Janeiro city. Intensive conservation actions, including reintroduction of zoo-born tamarins, increased numbers to about 3700 in 2014. The most severe yellow fever epidemic/epizootic in Brazil in 80 years reduced two of the largest GLT populations by over 90%. Herein we report the results of a 2023 survey of GLTs designed to examine the dynamics of population recovery following yellow fever. Results indicate that populations hard hit by yellow fever are recovering due in part to immigration from adjacent forest fragments. No local extirpations were observed. About 4800 GLTs live in the survey area. This represents a 31% increase since the baseline survey completed in 2014. Two factors explain most of the increase: four large areas that had no GLTs or very low-density populations in 2014 are now at moderate density (three areas) or low density (one area), explaining 71% of overall increase since 2014. Increase in forest area within our survey area may explain up to 16% of the increase in GLT numbers since 2014. Results of computer simulations suggest that strengthening forest connectivity will facilitate metapopulation resilience in the face of mortality factors such as yellow fever.

Gastric emphysema and pneumatosis intestinalis in two common marmosets with duodenal dilation syndrome.

BACKGROUND: Common marmosets (Callithrix jacchus) are widely used as primate experimental models in biomedical research. Duodenal dilation with chronic vomiting in captive common marmosets is a recently described life-threatening syndrome that is problematic for health control. However, the pathogenesis and cause of death are not fully understood. CASE PRESENTATION: We report two novel necropsy cases in which captive common marmosets were histopathologically diagnosed with gastric emphysema (GE) and pneumatosis intestinalis (PI). Marmoset duodenal dilation syndrome was confirmed in each case by clinical observation of chronic vomiting and by gross necropsy findings showing a dilated, gas-filled and fluid-filled descending duodenum that adhered to the ascending colon. A diagnosis of GE and PI was made on the basis of the bubble-like morphology of the gastric and intestinal mucosa, with histological examination revealing numerous vacuoles diffused throughout the lamina propria mucosae and submucosa. Immunostaining for prospero homeobox 1 and CD31 distinguished gas cysts from blood and lymph vessels. The presence of hepatic portal venous gas in case 1 and possible secondary bacteremia-related septic shock in case 2 were suggested to be acute life-threatening abdominal processes resulting from gastric emphysema and pneumatosis intestinalis. CONCLUSIONS: In both cases, the gross and histopathological findings of gas cysts in the GI tract walls matched the features of human GE and PI. These findings contribute to clarifying the cause of death in captive marmosets that have died of gastrointestinal diseases.

Molecular detection of Sarcocystis sp. in a kept under human care black capuchin monkey (Sapajus nigritus., Goldfuss 1809) with necrotizing encephalitis.

A senile male black capuchin monkey (Sapajus nigritus) kept under human care in a Zoo was found dead after 2 weeks presenting signals of weight loss and hyporexia. Histopathological revealed a necrotizing encephalitis. Although it was not observed microscopically, Sarcocystis sp infection was detected in brain tissue from molecular assays. These infections have been rarely described in neotropical primates, particularly associated with tissue lesions.