Genetic differences of dengue virus 2 in patients with distinct clinical outcome

The genetic diversity of the dengue virus is characterized by four circulating serotypes, several genotypes, and an increasing number of existing lineages that may have differences in the potential to cause epidemics and disease severity. Accurate identification of the genetic variability of the virus is essential to identify lineages responsible for an epidemic and understanding the processes of virus spread and virulence. Here, we characterize, using portable nanopore genomic sequencing, different lineages of dengue virus 2 (DENV-2) detected in 22 serum samples from patients with and without dengue warning signs attended at Hospital de Base of São José do Rio Preto (SJRP) in 2019, during a DENV-2 outbreak. Demographic, epidemiological, and clinical data were also analyzed. The phylogenetic reconstruction and the clinical data showed that two lineages belonging to the American/Asian genotype of DENV-2—BR3 and BR4 (BR4L1 and BR4L2)—were co-circulating in SJRP. Although preliminary, these results indicate no specific association between clinical form and phylogenetic clustering at the virus consensus sequence level. Studies with larger sample sizes and which explore single nucleotide variants are needed. Therefore, we showed that portable nanopore genome sequencing could generate quick and reliable sequences for genomic surveillance to monitor viral diversity and its association with disease severity as an epidemic unfolds.