With the arrival of coronavirus disease 2019 (COVID‐19) in Brazil in February 2020, several preventive measures were taken by the population aiming to avoid severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection including the use of masks, social distancing, and frequent hand washing then, these measures may have contributed to preventing infection also by other respiratory viruses. Our goal was to determine the frequencies of Influenza A and B viruses (FLUAV/FLUBV), human mastadenovirus C (HAdV‐C), Enterovirus 68 (EV‐68), and rhinovirus (RV) besides SARS‐CoV‐2 among hospitalized patients suspect of COVID‐19 with cases of acute respiratory disease syndrome (ARDS) in the period of March to December 2020 and to detect possible coinfections among them. Nucleic acid detection was performed using reverse‐transcription quantitative polymerase chain reaction (RT‐qPCR) in respiratory samples using naso‐oropharyngeal swabs and bronchoalveolar lavage. A total of 418 samples of the 987 analyzed (42.3%) were positive for SARS‐CoV‐2, 16 (1.62%) samples were positive for FLUAV, no sample was positive for FLUBV or EV‐68, 67 (6.78%) samples were positive for HAdV‐C, 55 samples were positive for RV 1/2 (26.3%) and 37 for RV 2/2 (13.6%). Coinfections were also detected, including a triple coinfection with SARS‐CoV‐2, FLUAV, and HAdV‐C. In the present work, a very low frequency of FLUV was reported among hospitalized patients with ARDS compared to the past years, probably due to preventive measures taken to avoid COVID‐19 and the high influenza vaccination coverage in the region in which this study was performed.

Rotavirus (RV) is an important viral pathogen causing diarrhea in piglets and other mammals worldwide. We describe 34 cases from 4 diarrheal outbreaks caused by RV in unvaccinated farrowing units in southern Brazil from 2011 to 2013. We performed autopsy, histologic examinations, bacterial culture, RV immunohistochemistry (IHC), and enteric virus detection through molecular assays for rotavirus A, B, and C, transmissible gastroenteritis virus, porcine epidemic diarrhea virus, sapovirus, norovirus, and kobuvirus. Histologically, villus atrophy (29 of 34) and epithelial vacuolation (27 of 34) occurred in all 4 outbreaks. Cell debris in the lamina propria occurred in 20 cases, mostly from outbreaks A (8 of 11), C (4 of 6), and D (7 of 11). IHC was positive for RV in 21 of 34 samples. RT-PCR was positive for RV in 20 of 30 samples; RV-C was the most frequently detected RV (n = 17). Kobuvirus was detected in 11 samples, and, in 3 of them, there was single detection of this enteric virus.

Summary: Mosquito borne flaviviruses cause a series of important diseases in humans and animals. These viruses are maintained in cycles involving replication in mosquito and in vertebrate hosts. Most natural hosts are vertebrate animals living in sylvatic or peridomestic environments. Human contact with these environments may result in host shifts that lead to the establishment of urban transmission cycles. Zika virus is a Flavivirus that persists in nature in a transmission cycle involving non-human primates (NHP). Its recent emergence in Brazil has shed light upon the importance of surveying this agent in Brazilian sylvatic environments. Here we present histopathological and molecular evidence that free ranging howler monkeys ( Alouatta guariba ) in Southern Brazil are infected by ZIKV closely related to African lineage MR766. Nine NHP were nested RT-PCR positive for ZIKV RNA. Sequence analysis revealed 96 to 98% identity to ZIKV MR766 and 85% identity to ZIKV P6-740, the current epidemic strain. The affected howler monkeys presented discrete inflammatory infiltrates in several tissues and immunohistochemichal (IHC) labeling of viral antigen was observed in placenta. These findings point to the circulation of African lineage Zika virus in the Americas in non-human primates. And raises the possibility that ZIKV was introduced into the Americas on more than one occasion.

Arboviral diseases comprise a group of important infectious diseases imposing a heavy burden to public health in many locations of the world. Orthoflaviviruses are viruses belonging to the genus Orthoflavivirus; this genus includes some of the most relevant arboviruses to human health. Orthoflaviviruses can infect several different hosts, with some species being transmitted in cycles involving birds and anthropophilic mosquitoes and others transmitted between mammals and mostly Aedes sp. mosquitoes. Some of the most important sylvatic reservoirs of orthoflaviviruses are non-human primates (NHPs). Many flaviviruses that infect NHPs in nature have the potential to cause epidemics in humans, as has been observed in the cases of Orthoflavivirus denguei (dengue virus – DENV), Orthoflavivirus flavi (yellow fever virus – YFV), and Orthoflavivirus zikaense (Zika virus – ZIKV). In this minireview, we discuss important aspects regarding history, ecology involving NHP, distribution, disease outcome, and pathogenesis of these three major orthoflaviviruses that affect humans and NHP and relate this information to the potential of using NHP as experimental models. In addition, we suggest some orthoflaviviruses that could be better investigated, both in nature and in experimental studies, in light of the recent revolution in molecular biology.