The nonhuman primate (NHP) model has been a cornerstone in the development of effective therapeutic and prophylactic interventions for HIV-1 infection. Yet, despite promising results in this key preclinical setting, major efficacy trials of HIV vaccines have failed to exhibit sufficient protection to meet their endpoint efficacy criteria. Similarly, the recent Antibody-Mediated Prevention (AMP) trials (HVTN 703, 704), which tested the ability of passive immunization with the broadly neutralizing antibody VRC01, also failed to meet predetermined overall efficacy criteria. Cumulatively, both active and passive vaccination regimens that have demonstrated the ability to provide protection in NHPs have not provided sufficient benefits in clinical field trials, raising questions about how to optimally model the challenging clinical reality facing HIV-1 vaccine developers. Here, with a goal of highlighting means whereby gaps might be addressed, we discuss some factors that may influence consistency between NHP experiments and translation between clinical and preclinical settings in both active and passive vaccine regimens. We conclude that results from the AMP trials provide a key benchmark that has high value in gauging the clinical prospects of humoral immune responses induced by vaccines or provided by passive antibody prophylaxis. The promise of new knowledge gained through carefully designed testing of new interventions and therapeutics motivates continued exploration of means to model humoral immunity to HIV-1 in preclinical models.

An infant Brown Howler Monkey with a fracture of the left humerus was treated using a titanium locking plate and screws. The patient showed excellent recovery, using the limb within 24 h post-procedure. The surgical technique was effective, enabling early limb function recovery and the animal release.

Ultrasound is a key diagnostic tool for evaluating reproductive anatomy and monitoring reproductive health in nonhuman primates. This study describes the reproductive system of female Alouatta caraya using ultrasonography.

The primate gastrointestinal tract is home to bacteria, which may be associated with its habitat. In Malaysia, wild stump-tailed macaques (Macaca arctoides) are found solely in the northern region of Peninsular Malaysia. No information is currently available regarding the intestinal microbiota of wild or captive Malaysian stump-tailed macaques. In this study, a fecal metabarcoding approach was utilized to determine the gut microbiome composition of wild and captive M. arctoides and how these microbial communities respond to the host's external environment. To elucidate these relationships, 16S rRNA was amplified and sequenced using the MiSeq platform, with 300 paired-end sequences. We identified 18 phyla, 38 orders, 46 families, 76 genera, and 131 species in the stump-tailed macaque samples. The most prevalent bacterial families in the gut of M. arctoides were Firmicutes (4.69%), Spirochaetes (2.87%), and Proteobacteria (2.40%). Our analysis did not reveal any substantial differences between the habitat environment and gut microbiome composition in M. arctoides. Nonetheless, to the best of our knowledge, this study is the first to document the gut microbiome of the wild M. arctoides population in Peninsular Malaysia. Future studies are required to explore and better understand potential zoonotic pathogens harbored in stump-tailed macaques.

Spontaneous meningiomas are rarely reported in nonhuman primates, and among the documented cases, only a few are thoroughly characterized. This report describes a case of atypical meningioma in a pregnant rhesus macaque (Macaca mulatta) that exhibits pathobiological features that mirror humans.

Cardiovascular and hemodynamic status can both be modified by cardiovascular risk factors which themselves depend on housing conditions.

The Bonnet macaque (Macaca radiata radiata) is a highly adaptive, anthropocentric, and commensal species that inhabits urban habitats with provisioned dietary habits. It is a subject of various scientific studies, particularly concerning its hematological and serum biochemical parameters. However, comprehensive baseline datasets are scarcely available, with existing data mostly derived from lab-maintained animals rather than wild individuals. The objective of this study is to establish reference values for hematological and serum biochemical parameters of Bonnet macaques living in Bengaluru urban ecological conditions with varied dietary habits. The study area lies between 12°58' N and 13°00' N latitude and 77°30' E and 77°40' E longitude. Blood samples were collected with KFD permission from urban macaques across different parts of the city by trained veterinary professionals following all due standard protocols and ethics. The results revealed crucial comparative differences from the available literature data and across age and sex groups. The Shapiro-Wilk test was performed to determine the normal distribution of the dataset, and the results obtained are variable-specific. The established reference values will enable more accurate interpretation of hematological and serum biochemistry values specific to urban macaque populations.

Canine distemper virus (CDV) has markedly expanded its known host range over the recent past decades. CDV infection has been reported in old-world primates of the genus Macaca, with reports between the 1980s and 2008 in Japan and China. Over the past months, independent research groups in Brazil reported an individual case and two outbreaks of CDV infection affecting free-ranging marmosets (Callithrix spp.) from different regions of the country. Clinical manifestations, pathological changes and viral tropism in neotropical primates are discussed. Furthermore, potential consequences on conservation of endangered species of neotropical primates and potential host adaptation to primates that may eventually favor human infections are also discussed. It is still unclear whether these independent reports of CDV infection in neotropical primates in such a short period of time may be due to an epizootic situation or to an increased efficiency of the surveillance system in place in Brazil.

The Peruvian Amazon is an endemic region for integumentary leishmaniasis, characterized by multiple vectors species, diverse wildlife reservoirs, and human activities that influence disease transmission. Non-human primates (NHPs) have been implicated as potential reservoirs for Leishmania spp. and Trypanosoma cruzi in neighboring Brazil, but their role in Cacajao spp. remains unknown. This study aimed to detect Leishmania spp. and T. cruzi DNA in semi-captive Peruvian bald uakaris (Cacajao calvus) housed at the Pilpintuwasi Rescue Center, Iquitos, Peru.

Leptospirosis is an emerging zoonotic disease caused by pathogenic Leptospira spp., affecting a wide range of domestic and wild mammals including nonhuman primates (NHPs). Despite rising incidence rates in both NHPs and humans, there is a lack of comprehensive resources addressing leptospirosis in NHPs from a veterinary perspective in a One Health approach. The close phylogenetic relationship between NHPs, humans and the similarities in disease progression may reveal valuable insights into the pathophysiology, diagnosis, treatment, control measures, and surveillance of leptospirosis. This review synthesizes existing literature on leptospirosis in NHPs, focusing on diagnosis, control measures, and surveillance. It offers insights into the prevalence among NHPs, environmental and civilization factors affecting Leptospira spp. dynamics, and recommendations for the diagnosis, management, and monitoring of leptospirosis. The findings highlight the need for coordinated research efforts and integrated surveillance systems to reduce leptospirosis risk in NHPs.

Tongue squamous cell carcinoma (TSCC) is a typical and prevalent neoplasm in non-human primates (NHPs). However, comprehensive pathological and immunohistochemical analyses of TSCC in rhesus monkeys have been infrequently documented.

A managed-care female common marmoset developed a rare C-cell carcinoma in the right thyroid lobe, characterized by capsular and intrathyroidal invasion. Neoplastic plasmacytoid cells arranged in sheets exhibited a morphological and immunophenotypic profile (calcitonin+, chromogranin A+, CK7+, INSM1+, TTF-1) that closely resembles human thyroid C-cell tumors.

Acclimation involves physiological adjustments to environmental factors such as geographic origin and housing conditions. Proper acclimation is essential for animal welfare and ensuring the reliability of experimental data. However, the long-term acclimation of cynomolgus macaques has not been systematically examined. Therefore, we compared serum chemistry values between cynomolgus macaques from Vietnam and housed in Laos. The Vietnamese-imported macaques were then monitored while housed indoors at the Korean Institute of Toxicology (KIT), Korea for 13 months.

Two male marmosets underwent vasectomy without complications. Azoospermia was confirmed by computer-assisted semen analysis (CASA) 5 weeks later. Both were co-housed with embryo transfer recipient females 6 weeks after surgery. Vasectomy may be accompanied by post-vasectomy semen analysis such as CASA, to ensure safe and reliable sterilization for research and captive breeding management in marmosets.

Baboons are valuable models for human health research, yet existing hematology, serum chemistry, and growth reference data are limited by small sample sizes, narrow age ranges, and inconsistent reporting.

Spontaneous peripheral nerve sheath tumors (PNSTs) are rare and often benign neoplasms in veterinary species and humans. This report describes the clinical, gross, histopathological, and immunological findings of a spontaneous malignant PNST embedded deep within the soft tissue in the forearm of a 4-year-old captive male rhesus macaque (Macaca mulatta).

Evaluation of the cardiothoracic ratio (CTR) using chest radiography is a valuable tool for screening cardiac diseases; however, age-related changes in CTR remain unclear, particularly in Japanese macaques. This study assessed the CTR in juvenile Japanese macaques and examined its relationship with age and sex.

Liver injuries are among the most common and can have a major impact on primates' health. This study aimed to describe the occurrence and frequency of hepatobiliary morphological changes in wild and human-cared non-human primates from the state of Rio Grande do Norte, Brazil.

This study aimed to conduct a serological and molecular survey of Toxoplasma gondii in nonhuman primates under human care in the state of Rio de Janeiro.

Perinephric pseudocysts consist of variable accumulations of either urine, lymph, or blood in a fibrous sac surrounding one or both kidneys. Perinephric pseudocysts are occasionally reported in cats and humans and very rarely in other species. Here we describe a case of bilateral perinephric pseudocysts in an owl monkey.

Reproduction in captive chimpanzees (Pan troglodytes) can be controlled by the insertion of intrauterine devices (IUDs) for females who do not reliably take oral contraceptives. Previous literature describes the use of improvised devices made from syringe cases as a speculum to accommodate the depth of the vaginal vault.