Detection of a Multiple Circulation Event of Dengue Virus 2 Strains in the Northern Region of Brazil

Abstract

Dengue virus serotype 2 (DENV-2) is responsible for dengue epidemics on a global scale and is associated with severe cases of the disease. This study conducted a phylogenetic investigation of DENV-2 isolates from 2017 to 2021 originating from the northern states of Brazil. A total of 32 samples from DENV-2 isolates were analyzed, including 12 from Acre, 19 from Roraima, and one from Tocantins. Only one lineage of the Asian-American genotype and one lineage of the cosmopolitan genotype were observed: Lineage 1, Asian-American genotype (connection to Puerto Rico); Lineage 5, cosmopolitan genotype (connection to Peru). Our results provide important data regarding the study of DENV genotypes and lineage distribution and open up possibilities for probable introduction and dissemination routes.

Keywords: Asian-American genotype; arboviruses; cosmopolitan genotype; dengue virus serotype 2.

Figure 1

Maximum likelihood phylogenetic tree based on the alignment of the dataset comprising 156 DENV-2 genome sequences. The scale bar indicates the evolutionary distance in the number of nucleotide substitutions per site, and the bootstrap values are indicated on the main branches, with a focus on the cosmopolitan genotype (represented in green) and the Asian-American genotype (blue). Lineage 5 (cosmopolitan genotype) is represented in red. Lineage 1 (Asian-American genotype) is represented in cyan. The cosmopolitan genotype is divided into lineages 1–6. The Asian-American genotype is divided into lineages 1–4. The strains of the other genotypes not found are not described in the figure. The unclassified cosmopolitan genotype sequences do not belong to any of the six lineages. The name and information of the isolates characterized in this study are highlighted, including the sample identification number, country, state of origin, and collection date.

Figure 2

Map illustrating the possible route of introduction and dispersal of the Asian-American genotype of DENV-2 suggested by this study. The orange arrow indicates parallel dispersion from Puerto Rico through an unmapped route (Puerto Rico-Brazil/Tocantins, Acre, and Rondônia). The bifurcation region indicates only the intersection corresponding to parallel dispersion for the states of Acre, Tocantins, and Rondônia, not that the dispersion route necessarily includes the state in which the bifurcation region is located. In other words, the strains recorded in Brazilian states prior to 2020 likely originated from Puerto Rico. The colors delineate the states and the intersections between the regions of the countries (Blue: Tocantins, Brazil; Green: Acre, Brazil; Orange: Rondônia, Brazil; Red: border region with Brazilian states). The yellow gradient circle indicates potential strain dispersion routes to regions in the Americas and neighboring countries, originating from Puerto Rico as a secondary dissemination center. The map was created using QGIS software v.3.28, available at https://qgis.org/pt_BR/site/ (accessed on 9 June 2023).

Figure 3

Map illustrating the possible route of introduction and dispersal of the DENV-2 cosmopolitan genotype. The orange arrow indicates only the departure from the point of origin and arrival through an unmapped route (Madre de Dios, Peru) (Acre/Brazil-Goiás/Brazil), based on the analysis of sequences obtained from reports in the last five years and the sequences from this study. The highlighted arrow is not related to the virus dispersion route; it only indicates the departure from the point of origin (Madre de Dios, Peru, and Acre, Brazil) and the destination (via an unmapped route) of Goiás, Brazil. The colors represent the states and intersections between regions of the countries (Orange: Madre de Dios, Peru; Green: Acre, Brazil; Blue: Goiás, Brazil; Red: border region between Brazil and Peru). The yellow gradient circle indicates the potential spread of the strain to other regions of Brazil and neighboring countries. The map was created using QGIS software v.3.28, available at https://qgis.org/pt_BR/site/ (accessed on 9 June 2023).