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Chikungunya virus (CHIKV) is primarily associated with non-human-primates (NHPs) in Africa, which also infect humans. Since its introduction to Brazil in 2014, CHIKV has predominantly thrived in urban cycles, involving Aedes aegypti mosquitoes. Limited knowledge exists regarding CHIKV occurrence and implications in rural and sylvatic cycles where neotropical NHPs are potential hosts, from which we highlight Leontopithecus chrysomelas (Kuhl, 1820), the golden-headed lion tamarin (GHLT), an endangered species endemic to the Atlantic Forest (AF) in Southern Bahia State, Brazil. The present study investigated wild GHLT groups across two municipalities, Ilhéus and Una, Bahia. Surveys were conducted in three groups within cocoa agroforests (cabrucas) in Ilhéus, and four groups in anthropized forest and agroforestry fragments in Una, between 2021 and 2022. Thirty-two GHLT specimens were captured and chemically immobilized, examined and submitted to blood sample collection; nine specimens were later recaptured in 2022, totaling 41 samples. CHIKV viremia was not detected in any specimens (as assayed by RT-qPCR). Plaque reduction neutralization test (PRNT90) detected CHIKV antibodies in two (6.3%) GHLTs, with 10–20 antibody titers. Seroprevalence in 2021 was 5.6% and in 2022 was 8.7% with an incidence of 4.5%, whereas, a male adult tested seropositive in both years, suggesting either natural re-exposure and antibody maintenance over time. All samples tested seronegative for Mayaro Virus. Eight mosquito species from the Culicidae family were collected, identified and assayed for CHIKV genomes, showing negative results. This study provides the first evidence of natural CHIKV exposure among free-living GHLTs in Brazil, emphasizing their susceptibility and potential role as reservoirs. These findings underscore the possible consequences of anthropic disturbances in the Brazilian AF, without a seroprevalence difference between non-protected forest formations, agroforest fragments and various mosaic farming landscapes in South Bahia, and highlight the importance of conservation efforts for this endemic and endangered primate species. Author summary: Chikungunya virus (CHIKV) is an arbovirus, where in Africa non-human-primates (NHPs) are hosts of the sylvatic transmission cycle. Since 2014 in Brazil CHIKV is maintained in urban cycles, involving humans and Aedes aegypti mosquitoes. We have limited knowledge regarding CHIKV occurrence and implications in rural and sylvatic cycles where neotropical NHPs are present. In 2021 and 2022, we studied Culicidae mosquitoes and Leontopithecus chrysomelas (golden-headed lion tamarin -GHLT-), an endangered species endemic to the Atlantic Forest in Southern Bahia State, Brazil, at Ilhéus and Una municipalities. There was no evidence of genetic material of the virus in the GHLT and mosquitos, but we did find neutralizing antibodies as evidence of natural CHIKV exposure among free GHLT, that were present for at least five months. This could mean that GHLTs i) are susceptible to CHIKV infection, ii) may have a potential role as reservoir, and iii) are also important to include it in the epidemiological surveillance of arboviruses. Although we did not find a difference in the antibody titles in the tamarins between inhabiting the different land covers and soil uses, this endangered species could be infected in anthropogenic altered regions such as rural areas, as a consequence of anthropogenic pressure. [ABSTRACT FROM AUTHOR]

Restraint and threat of predation are possibly the most stressful events in wild animals' lives. Management techniques should, therefore, be improved to avoid or minimize suffering in such situations. Body mass and variation in behavior influence the techniques used during containment. Automatic traps are mostly used for small primates living in the lower canopy, while remotely delivered chemical immobilization is the recommended technique for larger primates, which live in the upper canopy. For both methods, careful physical restraint after the capture of the animal is essential. The use of equipment and materials that ensure biosecurity is imperative, as is choosing the most appropriate location for the collection of biological samples. Storage and transport must also be carried out in an adequate manner so as not to impair the samples. Here, therefore, we seek to describe capture, containment, and biological sample collection techniques with the intention of minimizing risks and increase success in the capture of Neotropical primates. [ABSTRACT FROM AUTHOR]

In recent decades, waves of yellow fever virus (YFV) from the Amazon Rainforest have spread and caused outbreaks in other regions of Brazil, including the Cerrado, a savannah-like biome through which YFV usually moves before arriving at the Atlantic Forest. To identify the vectors involved in the maintenance of the virus in semiarid environments, an entomological survey was conducted after confirmation of yellow fever (YF) epizootics at the peak of the dry season in the Cerrado areas of the state of Minas Gerais. In total, 917 mosquitoes from 13 taxa were collected and tested for the presence of YFV. Interestingly, mosquitoes of the Sabethes genus represented 95% of the diurnal captured specimens, displaying a peak of biting activity never previously recorded, between 4:30 and 5:30 p.m. Molecular analysis identified three YFV-positive pools, two from Sabethes chloropterus -from which near-complete genomes were generated-and one from Sa. albiprivus , whose low viral load prevented sequencing. Sa. chloropterus was considered the primary vector due to the high number of copies of YFV RNA and the high relative abundance detected. Its bionomic characteristics allow its survival in dry places and dry time periods. For the first time in Brazil, Sa. albiprivus was found to be naturally infected with YFV and may have played a role as a secondary vector. Despite its high relative abundance, fewer copies of viral RNA were found, as well as a lower Minimum Infection Rate (MIR). Genomic and phylogeographic analysis showed that the virus clustered in the sub-lineage YFV PA-MG , which circulated in Pará in 2017 and then spread into other regions of the country. The results reported here contribute to the understanding of the epidemiology and mechanisms of YFV dispersion and maintenance, especially in adverse weather conditions. The intense viral circulation, even outside the seasonal period, increases the importance of surveillance and YFV vaccination to protect human populations in affected areas.