Yellow fever (YF) is an acute and potentially fatal hemorrhagic disease caused by the Yellow Fever virus (YFV), endemic to sub-Saharan Africa and several tropical countries, including Brazil. In Brazil, the Amazon region is considered the main endemic area. YFV is maintained in a sylvatic cycle involving Neotropical primates and mosquitoes of the genera Haemagogus and Sabethes, acting as primary and secondary vectors, respectively. In March 2024, entomovirological surveillance was conducted in Santa Bárbara do Pará, Pará, Brazil. A total of 286 mosquitoes were collected, classified into 13 species across nine genera, and grouped into 33 pools. Seventeen pools were tested by RT-qPCR for Orthoflavivirus (YFV, DENV, WNV, SLEV), Alphavirus (CHIKV, MAYV), and Orthobunyavirus (OROV). YFV was detected in four Haemagogus janthinomys pools, with Ct values ranging from 22.2 to 27.9. Metagenomic sequencing confirmed the presence of YFV with assigned reads and >99% protein identity. Notably, the detection occurred without human cases or primate deaths, enabling timely vaccination of the local population. These findings confirm YFV circulation in forested areas of the Belém metropolitan region and reaffirm Hg. janthinomys as a key vector. Our study reinforces the relevance of early entomovirological surveillance and preventive strategies, such as vaccination, to mitigate yellow fever reemergence.

Vector-borne diseases account for over 17% of reported infectious diseases worldwide and are associated with approximately 700,000 deaths annually. The main vectors include mosquitoes, moths, sand flies, black flies, and ticks. Ticks deserve special attention because they transmit a wide range of pathogens, including viruses of major medical importance, such as tick-borne encephalitis virus (Orthoflavivirus encephalitidis) and Crimean-Congo hemorrhagic fever virus (Orthonairovirus haemorrhagiae), as well as animal-borne pathogens, such as African swine fever virus (Asfivirus haemorrhagiae). Recent advances in next-generation sequencing have expanded the ability to detect and characterize tick-borne viruses, revealing increasing viral diversity. However, for many of these viruses, aspects such as pathogenic potential, main vectors, and natural hosts remain unclear. To address this gap, we conducted an integrative literature review using the PubMed, SciELO, BVSalud, and Patuá-IEC databases. We analyzed 336 articles addressing various species of tick-borne viruses. The Flaviviridae, Phenuiviridae, and Nairoviridae families were the most frequently identified among the viral agents detected. Furthermore, we identified that as-yet-unclassified viruses have been frequently detected in different tick species, which sparks significant interest in investigating their potential interactions and public health implications. Investigating viral agents in tick populations is crucial for understanding viral diversity and assessing potential public health risks, especially in the current context of climate change.

The biting midges Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) is highly relevant to epidemiology and public health, as it includes species that are potential vectors of human and animal arboviruses. The aim of this study was to investigate the presence of RNA viruses in species of the genus Culicoides collected in the Carajás mining complex in the state of Pará. The biting midges were collected in the municipalities of Canaã dos Carajás, Curionópolis and Marabá and morphologically identified. A total of 1139 specimens of seven Culicoides species were grouped into eight pools and subjected to metagenomic analysis. Eight new insect-specific viruses (ISVs) were characterized and assigned to the order Tolivirales, the families Chuviridae, Nodaviridae, Iflaviridae, Mesoniviridae, and Flaviviridae, and the taxon Negevirus. All viruses identified were assigned to clades, families and taxa never reported in Culicoides in Brazil. This study demonstrated that biting midges harbor a significant diversity of RNA viruses, many of which are still unknown, highlighting the importance of studies aiming at virome of these insects.