INTRODUCTION:Neotropical primates (NTPs) present varying susceptibility to toxoplasmosis caused by Toxoplasma gondii, but their immunopathogenic responses remain poorly understood. MATERIALS AND METHODS:Local immune responses were characterized in the liver, spleen, and central nervous system (CNS) of 50 naturally infected NTPs (31 Callithrix spp.; 19 Alouatta spp.) by immunohistochemistry. Splenic white pulp morphometry, CD3+ T lymphocyte, Iba1+ macrophage/microglia, polymorphonuclear neutrophil quantification, and IFN-γ and IL-10 semi-quantification were performed. RESULTS:Both genera exhibited splenic white pulp hyperplasia. Within genera, marmosets showed predominant CD3+ infiltrates in the spleen and histiocytic infiltrates in the liver and CNS, whereas howler monkeys exhibited predominantly histiocytic infiltrates in all tissues. Between genera, marmosets had significantly higher splenic CD3+ T-cell (p < 0.05), Iba1+ macrophage (p = 0.030), and IFN-γ (p = 0.018) immunolabeling than howler monkeys.
An unconscious free-ranging rhesus macaque with suspected maternal trauma presented with dystocia and stillbirth. Following the stabilization, assisted obstetrical intervention resulted in the successful delivery of a full-term stillborn foetus with uneventful maternal recovery. Maternal trauma was considered a plausible contributor to foetal death, highlighting the importance of timely obstetrical management.
BACKGROUND:Rectal prolapse in wild chimpanzees has been rarely reported. We document a case of rectal prolapse in a wild young male chimpanzee at Mahale Mountains National Park, Tanzania. METHODS:An affected young male in the Mahale M group was observed with photographs/video and diagnosed according to operational criteria used in human (Oxford grading system). Cause and course of the prolapse were estimated by a set of longitudinal field data. RESULTS:An intermittently self-reducing full-thickness rectal prolapse was diagnosed. Protrusion fluctuated within minutes; tenesmus and diarrhea were absent; and the mucosa remained bright red and viable, without necrosis or myiasis. Post-traumatic pelvic-floor/anal-sphincter nerve dysfunction after conspecific bite injury on the buttock was estimated as the cause. CONCLUSIONS:This is the first report of rectal prolapse in wild chimpanzees. The detailed natural course of this persistent condition without medical intervention provides information relevant to case-specific management decisions in wild apes.
Pulmonary tuberculosis caused by the Mycobacterium tuberculosis complex (MTC) was diagnosed in a 6-year-old female rhesus macaque (Macaca mulatta) presented with a three-month history of intermittent coughing, dyspnea, weight loss, and inappetence. Hematological evaluation revealed moderate regenerative anemia and neutrophilic leukocytosis, while the thoracic radiography demonstrated a diffuse nodular interstitial pulmonary pattern consistent with tuberculosis. The diagnosis was confirmed by IS6110-targeted PCR. This case underscores the utility of combining radiographic and molecular diagnostic approaches for the early confirmation of tuberculosis in nonhuman primates and highlights its important zoonotic implications.
INTRODUCTION:Klebsiella spp. are opportunistic enterobacteria associated with a wide range of infections in humans and animals and are increasingly recognized as important pathogens due to their ability to acquire antimicrobial resistance. Captive wildlife populations, including non-human primates, may serve as carriers of these bacteria and are susceptible to bacterial outbreaks under certain management and environmental conditions. This study aimed to describe the antimicrobial susceptibility profile of Klebsiella spp. isolated from clinically healthy captive night monkeys (Aotus nancymaae) housed at the IVITA-Iquitos breeding center in the Peruvian Amazon. MATERIALS AND METHODS:A total of 86 clinically healthy night monkeys were sampled. Rectal swabs were collected for bacterial isolation and identification. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Associations between bacterial isolation and demographic variables were evaluated. RESULTS:Klebsiella spp. were isolated from 10.5% (9/86) of the animals. The frequency of isolation was highest among juveniles, followed by infants and adults, with a significant association between age group and bacterial isolation (p < 0.05). No association was observed with sex. Most isolates (79.2%) were susceptible to all tested antimicrobials, four isolates (16.7%) exhibited intermediate susceptibility to at least one antimicrobial, and only one isolate (4.2%) showed resistance, specifically to ciprofloxacin. No multidrug-resistant isolates were identified. DISCUSSION:The results indicate a low frequency of antimicrobial resistance among Klebsiella spp. isolates recovered from clinically healthy captive night monkeys. These findings provide baseline information on the occurrence of Klebsiella spp. and antimicrobial susceptibility in this population. Continued microbiological surveillance is recommended to support preventive health management and facilitate the early detection of changes in antimicrobial susceptibility patterns in captive neotropical primates.
INTRODUCTION:Natural hosts of simian immunodeficiency virus (SIV), including sooty mangabeys (SMs), maintain high viremia without progressing to AIDS and AIDS-associated histopathogenesis. The mechanisms underlying this protection and lack of pathogenesis remain incompletely understood, particularly in relation to monocyte/macrophage activation. METHODS:Plasma soluble CD163 (sCD163), monocyte CD163 expression, and monocyte subset phenotypes were quantified in uninfected and naturally SIV-infected SMs and compared with uninfected and SIV-infected rhesus macaques (RMs). Flow cytometry and multivariate analyses were used to assess monocyte activation and subset distribution. RESULTS:sCD163 levels and CD163 surface expression were increased in SIV-infected RMs but not SMs. SIV-infected SMs exhibited reduced CD14+CD16+ monocyte expansion and lower expression of CD64, MAC387, CD11b, and CCR2 compared with SIV-infected RMs. Machine learning identified CD14+CD16+CCR8+ monocytes as the top discriminator of SIV infection in SMs. CONCLUSION:These findings indicate a lack of monocyte activation in SMs that correlates with non-pathogenic infection.
BACKGROUND:The nonhuman primate (NHP) captive-bred colony of rhesus macaques (Macaca mulatta) maintained at the Primate Unit and Delft Animal Centre has shown a prevalence of spontaneous obesity. METHODS AND METHODS:Eight females were selected based on their body composition measurements. The study evaluated the impact of different environmental housing conditions and monitored biochemical parameters. This was followed by molecular screening for obesity-related genes. RESULTS:Statistically significant changes (p ≤ 0.05) were observed for body weight, abdominal circumference, and abdominal skinfold thickness, which remained higher in the obese group. Significant differences in the relative mRNA gene expression were also observed for leptin and circulating tumor necrosis factor alpha (TNFα). CONCLUSION:Based on these findings, the observed significant differences are likely attributable to the two distinct environmental housing conditions. Furthermore, this study identifies HbA1c, leptin, and TNFα as potential obesity biomarkers in this rhesus colony, offering valuable insight into mechanisms of human obesity.
BACKGROUND:Human-macaque conflict has become an increasing concern in urban and residential areas. Existing deterrent systems, particularly ultrasonic-based approaches relying on fixed frequencies or simple motion detection, have limited effectiveness and high false alarm rates. Moreover, most systems lack integration between detection, risk assessment, and adaptive response mechanisms. OBJECTIVE:To develop a smart-alarm system for detecting and mitigating long-tailed macaque intrusion in human residential environments. METHODS:Computer vision-based object detection was integrated with real-time risk assessment using distance and group size as key parameters. The system dynamically activates deterrent sound signals and sends real-time alerts via communication platforms. The system was deployed and evaluated in a real-world setting (Sriracha Campus, Kasetsart University). RESULTS:The system could effectively detect macaques and provide appropriate, timely deterrence responses, thereby reducing human-macaque conflict. CONCLUSIONS:This novel AI-based integrated framework combines detection, behavior analysis, and risk assessment for nonlethal wildlife management in shared human-animal environments.
Wildlife captive populations are important tools for threatened species conservation, and early identification of diseases must be prioritized. In this study, we test for the presence of anti-Toxoplasma gondii antibodies in non-human primates at a Zoo from Pernambuco State, Brazil. A Modified Agglutination Test (MAT ≥ 25) was carried out on serum samples from 28 individuals of nine species (Ateles chamek, Ateles marginatus, Ateles paniscus, Chlorocebus aethiops, Papio anubis, Papio hamadryas, Lagothrix lagotricha, Sapajus flavius, and Sapajus libidinosus) from two parvorders (Catarrhini and Platyrrhini). Among the tested animals, 19 (67.85%) from eight different species were seropositive, and only one S. flavius developed clinical toxoplasmosis. A statistical association was observed between age and presence of T. gondii antibodies, with adults and geriatric animals showing higher (p < 0.05) association than young ones. Local of born (in the zoo or out of the zoo), parvorder, and gender were not significantly associated (p > 0.05).
BACKGROUND:Infection of Entamoeba (amoebiasis) in the proboscis monkey (Nasalis larvatus), a Bornean endemic and endangered species of non-human primates (NHPs), has not been reported in Indonesia. PURPOSE:This study aimed to identify Entamoeba from captive proboscis monkeys at Surabaya Zoo, Indonesia. METHOD:Twenty fecal samples were collected from captive proboscis monkeys in the study area. Fecal samples were examined through coprological and molecular methods. FINDINGS:The prevalence of Entamoeba spp. by coprological and molecular techniques was 90% (18/20) and 100% (20/20), respectively, with two species identified: E. coli and E. moshkovskii. Molecular analysis confirmed Entamoeba spp. and E. coli infection, which have high genetic similarity to isolates previously reported in European countries and Asia. CONCLUSION:This study provides the first documentation of Entamoeba spp., E. coli, and E. moshkovskii from the captive proboscis monkeys in Indonesia. This data supports ex situ health management and assesses potential cross-species transmission risks.
A free-ranging road-killed brown howler monkey (Alouatta guariba clamitans) presented multiple mucosal-colored papules and plaques on oral mucosa. Pathological evaluation confirmed the diagnosis of epithelial hyperplasia with koilocytosis. Papillomavirus antigens were demonstrated by immunohistochemistry, and PCR was positive for partial amplification of Alouatta guariba papillomavirus 1 DNA.
Enteroparasites were investigated in free-ranging Saguinus ursulus from the eastern Brazilian Amazon. Parasites were detected in 76.5% (13/17) of capture events, with Prosthenorchis sp. most frequently detected (58.8%; 10/17). Animals showed good body condition and no clinical abnormalities. This is the first report of Prosthenorchis sp. infection in S. ursulus.
BACKGROUND:Owl monkeys (Aotus spp.) are a nocturnal nonhuman primate (NHP) native to central and South America that are used as infectious disease research models for human diseases, such as malaria and human immunodeficiency virus. Natural and infectious diseases may cause alterations in the hematology and serum biochemistry values, which necessitate the availability of reliable reference intervals for healthy animals. METHODS:In this study, hematology and serum chemistry reference intervals for Aotus nancymae were calculated from 191 healthy animals (95 female, 96 male) and were generated based on age class (juvenile, adult, geriatric), sex (adults only), and across the entire sample. RESULTS:Significant differences were observed in multiple parameters as a function of sex and age, some of which are inconsistent with existing data from Aotus spp. and other NHPs. CONCLUSIONS:The availability of age and sex specific reference intervals will be a valuable resource for monitoring the clinical health and effects of research interventions in owl monkeys.
This case represents the first reported use of Siemens Cios Spin mobile 3D C-arm system for diagnostic imaging for a congenital cleft palate in an adult rhesus macaque (Macaca mulatta). This technology provided a versatile, rapid, and on-site imaging modality with diagnostic value for craniofacial assessment that may also be applicable to other nonhuman primate species and the evaluation of additional anatomical structures.
INTRODUCTION:Bonobos (Pan paniscus) are endangered and uncommon in managed care. Prothrombotic and hypofibrinolytic states are encountered with cardiovascular disease, ischemic stroke, and neoplasia. MATERIALS AND METHODS:Twelve bonobos from one institution were evaluated during anesthetized exams. Samples were analyzed on a VCM Vet analyzer, obtaining results within 1 h. RESULTS:VCM parameters (median [IQR]) reflected clot formation: clot time 300 s [265-332], clot formation time 97 s [82-107], α-angle 65° [63-69]; clot strength: maximum clot formation 50 units [47-52], amplitude 10 min 40 units [35-44], and amplitude 20 min 47 units [43-51]; and clot lysis: index 30 min 99.97% [99.95-100.00] and index 45 min 98.10% [97.50-99.20]. VCM was compared to thromboelastography and coagulation testing. DISCUSSION:Bonobos were hypercoagulable when compared to canine reference intervals, consistent with chimpanzees. Bonobos medicated for hypertension in this study were hypocoagulable compared to normotensive individuals.
BACKGROUND:Toxoplasmosis and leishmaniosis are zoonotic diseases that affect several species of neotropical primates. METHODS:Three black lion tamarins (Leontopithecus chrysopygus) kept at a Brazilian zoo died due to a superacute disease. Tissue samples were collected for histopathology, cytology, PCR, and genotyping by PCR-RFLP and microsatellite (MS) analysis. RESULTS:Toxoplasma gondii was detected by PCR in all tissue samples analyzed. The Brazilian lineage Type BrII (ToxoDB-PCR-RFLP #11 genotype) was identified in three animals, and the analysis with MS confirmed the same source of infection. Amastigotes of Leishmania sp. were visualized in cytology and confirmed by IHC in the three animals. CONCLUSION:This is the first time that this genotype has been confirmed associated with an outbreak of toxoplasmosis affecting neotropical primates in Brazil, or associated with infection by Leishmania sp.
BACKGROUND:Anti-Müllerian hormone is widely used as a marker of ovarian reserve, but its stage-specific follicular origin remains unclear in the common marmoset (Callithrix jacchus). METHODS:Follicle diameters were reassessed histologically, and plasma anti-Müllerian hormone concentrations were measured using an ultrasensitive enzyme-linked immunosorbent assay and analyzed in relation to stage-specific follicle populations across 57 females of different ages. Age-related differences in plasma anti-Müllerian hormone were also evaluated. RESULTS:Histological measurements showed that antral follicles were smaller than previously reported. Plasma anti-Müllerian hormone declined with age (R2 = 0.51, p < 0.001) and was most strongly associated with bilateral medium antral follicle count per animal (R2 = 0.64, p = 0.0002), whereas associations with preantral stages were minimal. Immunostaining localized anti-Müllerian hormone mainly to granulosa cells of antral follicles. CONCLUSIONS:Circulating anti-Müllerian hormone in the common marmoset primarily reflects the developing antral follicle pool and may serve as a stage-specific biomarker of ovarian function.
Nonhuman primates (NHPs) have emerged as an indispensable model for studying HIV pathogenesis, vaccines, and therapies. The development of chimeric Simian/Human immunodeficiency viruses (SHIVs) has been constructed by inserting HIV-1 Env into the SIV (usually SIVmac239) backbone, and these have proved essential for evaluating HIV neutralizing antibody dynamics and efficacy in vivo, making studies testing the protective efficacy of human broadly neutralizing monoclonal antibodies (bNAbs) in nonhuman primates possible. The original constructs have been improved in several new SHIV strains to improve binding of the Env to the macaque CD4 receptor by an additional mutation, and further improvements continue to be made. Even with some limitations, NHP models using SHIV infection have contributed substantially to the advancement of HIV bNAb use in both adult and pediatric settings.
Juvenile and infant nonhuman primate models are critical for advancing pediatric HIV prevention and cure research but present unique biological and logistical challenges. Studies in juvenile Rhesus macaque must address seasonal breeding constraints, genetic diversity, limited tissue access, infant rearing complexities and age-specific drug dosing and anesthesia considerations. Neonatal immune systems differ markedly from adults, exhibiting heightened plasticity, rapid CD4+ T cell turnover and evolving antibody responses, suggesting a narrow window in early life when antiretroviral therapy may limit viral reservoir formation and support durable remission. To improve rigor and reproducibility, structured quality management systems were applied to non-GxP research, enhancing data integrity, and traceability. In this framework, once-weekly oral Islatravir provided complete protection against repeated low-dose vaginal challenge with SIVmac251, preventing viremia, seroconversion, and detectable proviral DNA. Standardized assays, centralized laboratories, and robust statistical design were emphasized to maximize translational impact.
