Lack of molecular evidence of fecal-borne viruses in capybaras from São Paulo state, Brazil, 2018-2020: a minor public health issue.

Capybara (Hydrochoerus hydrochaeris) is the world's largest rodent species distributed throughout South America. These animals are incredibly tolerant to anthropogenic environments and are occupying large urban centers. Capybaras are known to carry potentially zoonotic agents, including R. rickettsia, Leishmania spp., Leptospira spp., Trypanosoma spp., Salmonella spp., Toxoplasma gondii, and rabies virus. Focusing on the importance of monitoring potential sources of emerging zoonotic viruses and new viral reservoirs, the aim of the present study was to assess the presence of fecal-borne viruses in the feces of capybaras living in urban parks in São Paulo state, Brazil. A total of 337 fecal samples were collected between 2018 and 2020 and screened for the following: (i) Rotavirus group A (RVA) by ELISA; (ii) non-RVA species and Picobirnavirus (PBV) using PAGE; (iii) Human Bocaparvovirus (HBoV), Bufavirus (BuV), Tusavirus (TuV), and Cutavirus (CuV) qPCR; (iv) Human Enterovirus (EV), Norovirus GII (NoV), and Hantavirus by in houses RT-qPCR; (v) SARS-CoV-2 via commercial RT-qPCR kit assay; and (vi) Astrovirus (AstV) and Adenovirus (AdV) using conventional nested (RT)-PCRs. All fecal samples tested were negative for fecal-borne viruses. This study adds further evidence that the fecal-borne viruses is a minor public health issue in Brazilian capybaras, at least during the surveillance period and surveyed areas. Continuous monitoring of sylvatic animals is essential to prevent and control the emergence or re-emergence of newly discovered virus as well as viruses with known zoonotic potential.

Predicting Antigenic Peptides from Rocio Virus NS1 Protein for Immunodiagnostic Testing Using Immunoinformatics and Molecular Dynamics Simulation.

The mosquito-borne disease caused by the Rocio virus is a neglected threat, and new immune inputs for serological testing are urgently required for diagnosis in low-resource settings and epidemiological surveillance. We used in silico approaches to identify a specific antigenic peptide (p_ROCV2) in the NS1 protein of the Rocio virus that was theoretically predicted to be stable and exposed on its surface, where it demonstrated key properties allowing it to interact with antibodies. These findings related to the molecular dynamics of this peptide provide important insights for advancing diagnostic platforms and investigating therapeutic alternatives.