In Brazil, the state of Tocantins, located in north-central Brazil, has experienced a significant number of cases of arboviral disease, particularly Dengue virus (DENV). This study aimed to deepen the knowledge on DENV circulation within that state by conducting full genome sequencing of viral genomes recovered from 61 patients between June 2021 and July 2022. There were a total of 8807 and 20,692 cases in 2021 and 2022, respectively, as reported by the state’s Secretary of Health. Nucleotide sequencing confirmed the circulation of DENV serotype 1, genotype V and DENV serotype 2, genotype III in the State. Younger age groups (4 to 43 years old) were mostly affected; however, no significant differences were detected regarding the gender distribution of cases in humans. Phylogenetic analysis revealed that the circulating viruses belong to DENV-1 genotype V American and DENV-2 genotype III Southeast Asian/American. The Bayesian analysis of DENV-1 genotype V genomes sequenced here are closely related to genomes previously sequenced in the state of São Paulo. Regarding the DENV-2 genotype III genomes, these clustered in a distinct, well-supported subclade, along with previously reported isolates from the states of Goiás and São Paulo. The findings reported here suggest that multiple introductions of these genotypes occurred in the Tocantins state. This observation highlights the importance of major population centers in Brazil on virus dispersion, such as those observed in other Latin American and North American countries. In the SNP analysis, DENV-1 displayed 122 distinct missense mutations, while DENV-2 had 44, with significant mutations predominantly occurring in the envelope and NS5 proteins. The analyses performed here highlight the concomitant circulation of distinct DENV-1 and -2 genotypes in some Brazilian states, underscoring the dynamic evolution of DENV and the relevance of surveillance efforts in supporting public health policies.

The dengue virus (DENV) is an arbovirus belonging to the Flaviviridae family; the species comprises four antigenically distinct serotypes (DENV–1, DENV–2, DENV–3, and DENV–4), which are further subdivided into genotypes. The virus is transmitted to humans through mosquito bites, primarily from the Aedes spp. genus. Dengue is endemic in various parts of the world, including tropical and subtropical regions of Asia, Latin America, Africa, and Oceania. In Brazil, the state of Tocantins, located in north-central Brazil, has experienced a significant number of arboviral disease cases, particularly dengue. This study aimed to monitor DENV circulation within the state by conducting full genome sequencing of viral genomes recovered from 61 patients between June 2021 and July 2022. During this period, both DENV-1 and DENV-2 serotypes were identified. Our findings confirm the circulation of DENV serotypes 1 and 2 in Tocantins, affecting males and females equally, with younger age groups (4 to 43 years old) being the most susceptible. Phylogenetic analysis revealed that the circulating viruses belong to DENV–1 genotype V American and DENV–2 genotype III Southeast Asian/American. The Bayesian analysis of DENV-1 Genotype V sequenced here is closely related to genomes previously sequenced in the state of São Paulo. Regarding DENV-2 genotype III genomes, these are clustered in a distinct, well-supported subclade, along with previously reported isolates from the states of Goiás and São Paulo. In both cases, our results suggest that multiple introductions of these genotypes occurred in the Tocantins state. This observation highlights the significant impact of major population centers in Brazil on virus dispersion, including other Latin-American countries and the USA. In the SNP analysis, DENV-1 displayed 122 distinct missense mutations, while DENV-2 had 44, with significant mutations predominantly occurring in the envelope and NS5 proteins. The analyses performed here reveal the concomitant circulation of distinct DENV-1 and -2 genotypes in some Brazilian states, underscoring the dynamic evolution of the DENV and the ongoing significance of surveillance efforts in supporting public health policies.