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The absence of an adequate animal model for studies has limited the understanding of congenital Zika syndrome (CZS) in humans during the outbreak in America. In this study, we used squirrel monkeys ( Saimiri collinsi ), a neotropical primate (which mimics the stages of human pregnancy), as a model of Zika virus (ZIKV) infection. Seven pregnant female squirrel monkeys were experimentally infected at three different gestational stages, and we were able reproduce a broad range of clinical manifestations of ZIKV lesions observed in newborn humans. Histopathological and immunohistochemical analyses of early-infected newborns (2/4) revealed damage to various areas of the brain and ZIKV antigens in the cytoplasm of neurons and glial cells, indicative of CZS. The changes caused by ZIKV infection were intrauterine developmental delay, ventriculomegaly, simplified brain gyri, vascular impairment and neuroprogenitor cell dysfunction. Our data show that the ZIKV infection outcome in squirrel monkeys is similar to that in humans, indicating that this model can be used to help answer questions about the effect of ZIKV infection on neuroembryonic development and the morphological changes induced by CZS.

During the Zika virus (ZIKV) outbreak in Brazil (2015–2016), the clinical manifestations associated with its infection were complex and included miscarriage and congenital malformations, not previously described. In this study, we evaluated the prenatal conditions of pregnant female squirrel monkeys ( Saimiri collinsi ) infected during different gestational thirds (GTs) and assessed all clinical aspects, diagnostic imaging, viremia and the immune response. In our study, 75% of the infected animals in the 1st GT group had significant clinical manifestations, such as miscarriage and prolonged viremia associated with a late immune response. Consequently, their neonates showed fetal neuropathology, such as cerebral hemorrhage, lissencephaly or malformations of the brain grooves, ventriculomegaly, and craniofacial malformations. Thus, our study demonstrated the relevance of pregnant squirrel monkeys as a model for the study of ZIKV infection in neonates due to the broad clinical manifestations presented, including the typical congenital Zika syndrome manifestations described in humans.

In the history of yellow fever (YF) outbreaks in Brazil, howler monkeys (Alouatta sp.) and marmosets (Callithrix sp.) have been among the most affected genera, exhibiting significant hepatic injuries similar to those seen in humans. However, limited information exists regarding yellow fever virus (YFV) infection in their central nervous system (CNS). To address this gap, an epidemiological study was conducted to assess tissue changes, viral detection, and cytokine profiles in the brains of both neotropical primate species when they are naturally infected with YFV. A total of 22 brain samples from these species (8 from Alouatta sp. and 14 from Callithrix sp.) showing infection with YFV in the liver via immunohistochemistry (IHC) were selected. From them, YFV antigen detection occurred in 35.7% (5/14) of Callithrix sp. brain samples and 87.5% (7/8) of Alouatta sp. samples, with a higher frequency of viral antigen quantification in Callithrix sp. Both species exhibited similar CNS lesions, characterized by congestion, low hemorrhage, limited inflammatory infiltration interstitial and perivascular edema associated with neuronal degeneration, neurophagy, and higher cell death (necrosis and apoptosis) quantification. Pro- and anti-inflammatory cytokine profiles were balanced, with TNF-α and IL-1β playing a key role in inflammation, while IL-10 and IL-13 exhibited a prominent role in immunomodulation, suggesting an anti-inflammatory modulation typical of flaviviruses occurs. This study demonstrates that YFV can induce CNS lesions in neotropical primates, establishing it as a secondary target of viral tropism. These findings highlight the importance of collecting nervous tissue during epizootics, particularly in Callithrix sp., as such tissue is often overlooked despite its critical role in disease monitoring.

During the Zika virus (ZIKV) outbreak and after evidence of its sexual transmission was obtained, concerns arose about the impact of the adverse effects of ZIKV infection on human fertility. In this study, we evaluated the clinical-laboratory aspects and testicular histopathological patterns of pubertal squirrel monkeys (Saimiri collinsi) infected with ZIKV, analyzing the effects at different stages of infection. The susceptibility of S. collinsi to ZIKV infection was confirmed by laboratory tests, which detected viremia (mean 1.63 × 106 RNA copies/µL) and IgM antibody induction. Reduced fecal testosterone levels, severe testicular atrophy and prolonged orchitis were observed throughout the experiment by ultrasound. At 21 dpi, testicular damage associated with ZIKV was confirmed by histopathological and immunohistochemical (IHC) analyses. Tubular retraction, the degeneration and necrosis of somatic and germ cells in the seminiferous tubules, the proliferation of interstitial cells and an inflammatory infiltrate were observed. ZIKV antigen was identified in the same cells where tissue injuries were observed. In conclusion, squirrel monkeys were found to be susceptible to the Asian variant of ZIKV, and this model enabled the identification of multifocal lesions in the seminiferous tubules of the infected group evaluated. These findings may suggest an impact of ZIKV infection on male fertility.

Oropouche virus (OROV) is an arbovirus endemic in the Amazon region that closely resembles other arboviruses in terms of human disease, leading to potential misdiagnoses. The virus ecology has mostly restricted its occurrence to the Amazon biome; however, after a large 2023–24 OROV epidemic in the Brazilian Amazon region, outbreaks are being reported across Brazil and in other countries in Latin America. Here, we investigate the OROV spread outside Amazonia. In this genomic and epidemiological study, OROV cases from January, 2023, to July, 2024, provided by the General Coordination of Public Health Laboratories of Brazil on Aug 1, 2024, were compared by geographical location (Amazon vs non-Amazon) and municipal population size, and a linear mixed model was employed to assess the relationship between agricultural area size and cases. OROV-positive samples from central laboratories of five non-Amazonian Brazilian states were sequenced using an amplicon-based approach. Bayesian phylogeographical analysis was performed with near full-length viral genomes, incorporating individual travel histories when relevant. The estimated dates of viral introductions in each sampled location were then contextualised with public epidemiological data. Epidemic data show that outside the Amazon region, OROV cases frequency was 3·9-times higher in small municipalities than in large municipalities. The planted areas of some agricultural products, such as banana plantations, were positively correlated (r=0·39, p<0·0001) with OROV cases. The linear mixed model revealed that, besides banana, cassava also has larger (p<0·05) planted areas in municipalities with OROV cases when compared with those with no cases. The phylogenetic analysis of 32 new OROV genomes reconstructed multiple exportation events of the newly identified reassortant lineage from the Amazon to other Brazilian regions between January and March, 2024. At least three of the previously described OROV phylogenetic clades circulating in the Amazon were the source of viral introductions. Molecular clock analysis estimated that viral introductions happened from 50 days to 100 days before detecting the outbreaks in each state. Our results confirm that the novel OROV reassortant lineage spread from the Amazon to other regions in early 2024, successfully establishing local transmission. The fact that outbreaks were observed in small municipalities, instead of large urban centres, suggests that local ecological conditions that are ideal for OROV vector occurrence, such as the banana plantation environment, might be important factors driving its spread in Brazil. DECIT, CNPq, FAPEAM, and Inova-Fiocruz. For the Portuguese translation of the abstract see Supplementary Materials section.

Background Dignity Therapy is a person-centered psychotherapeutic intervention designed for people approaching the end of life, fostering reflection on meaningful aspects of life and creating a testimonial legacy. Since 2011, randomized trials have demonstrated its value in addressing psychospiritual needs and preserving dignity in palliative care. However, no controlled studies have been conducted in Latin America to assess its effectiveness within local cultural contexts. Methods This is a protocol for an exploratory, randomized, parallel-group clinical trial (1:1 allocation) with an open-label design. A total of 96 hospitalized individuals with advanced cancer will participate, all receiving care from the Palliative Care Service of a university hospital in Fortaleza, Brazil. The control group will receive usual palliative care, while the intervention group will receive the same care along with Dignity Therapy, delivered in three structured sessions. Assessments will be conducted at baseline (T1), at the end of the intervention (T2), and short-term follow-up (T3). The primary outcome will be the perceived dignity impact of the intervention, measured by the Dignity Impact Scale. Secondary outcomes will include spiritual well-being, hope, anxiety, depression, and distress. Perceptions of the intervention experience will also be collected from individuals in the intervention group. The primary analysis will be performed using linear mixed models. Discussion This trial will provide evidence on the feasibility and potential benefits of Dignity Therapy in supporting dignity and spiritual well-being among individuals with advanced cancer, while also examining how the intervention performs within distinct cultural contexts that may shape perceptions of dignity and end-of-life care. Trial registration Registro Brasileiro de Ensaios Clínicos (ReBEC), RBR-8r3vzw5. Registered on 13 October 2025.

Background and aim Diabetes mellitus (DM) represents an important risk factor for diseases, with impact on morbidity and mortality in the Brazilian population. Comprehensive care of people with diabetes is a great challenge in all levels of healthcare. Digital care coupled with Primary Health Care (PHC) strategies has become an appealing alternative. This study aimed to analyze characteristics of a population within a diabetes care pathway and to investigate associations between digital monitoring and reduction in levels of glycated hemoglobin (HbA1 c ). Methods This is a longitudinal study with 88 working adults within the diabetes care pathway of a digital PHC service. All data came from patients’ medical records, from March 2022 to December 2023. A multilevel model was described considering 117 HbA1 c measurements over time as a fixed effect. Also, the intraclass correlation coefficient (ICC) was calculated to quantify the proportion of clinical and total variance. A survival analysis with changes in HbA1 c levels was performed using Kaplan–Meier survival curves with log-rank test. Results The digital monitoring of DM within a diabetes care pathway, via digital health services, led to reductions in HbA1c levels over time. A significant difference was observed between the first and last measurements (7.3% and 6.4%, respectively; p  < 0.05). Conclusions The study provides a type of diabetes care that can contribute to the health and disease control and demonstrates the strength of digital PHC for monitoring diabetic patients and should help PHC decision-makers and researchers to better understand how to improve diabetic patient management services using digital health.