Introducción:

The dengue virus (DENV) is responsible for the Dengue Fever, one of the main causes of severe disease and death in tropical countries of Asia and Latin America. In Peru, the dengue is an endemic and unattended disease that represents a serious public health problem. Serotype 2 of the dengue virus (DENV-2) is the most common in outbreaks and is responsible for more severe clinical manifestations.

Objetivos:

The objective of this study is the molecular characterization of the DENV-2 genotypes that circulate in three endemic areas of Peru.

Materiales y Métodos:

Twenty-nine hundred and fifty (2,950) blood serum samples were collected from patients with a clinical diagnosis of acute febrile illness in the endemic regions of Huánuco, Piura and Cajamarca during 2016-2021. The identification of DENV and DENV-2 in the samples was conducted through real-time PCR (RT-PCR), and the viral envelope (E) gene was then sequenced. The phylogenetic reconstruction was conducted by Bayesian inference with the Markov chain Monte Carlo (MCMC) algorithm.

Resultados:

From the total analyzed samples, 807 (27.36%) cases were positive for DENV, 483 (59.7%) cases of which were positive for DENV-2. The phylogenetic inference of 31 nucleotide sequences showed the co-circulation of the American/Asian (AM/AS) and cosmopolitan genotypes of DENV-2; of these two genotypes, the AM/AS 2 lineage was the only one that circulated before 2019 and the cosmopolitan was predominantly observed in subsequent outbreaks. It is also reported that the AM/AS 2 lineage is diverse and forms four monophyletic groups that are closely related to the endemic areas in the study sampling. The results of this study show that, while in 2016 in Huánuco circulated the AM/AS 2 lineage strain that was introduced in 2010 in Peru, in Piura circulated a new variant with mutations K163R and S474P in the domain I and the transmembrane region of the E protein. Furthermore, a new variant with V197L and V382A substitutions in domains II and III, respectively, was identified in the 2017 outbreak in Cajamarca, and a variant with own I379T and V484I substitutions in the 2020-2021 outbreaks was also identified in the same region

Discusión / Conclusiones:

The study reported 3 autochthonous variants of lineage 2 of AM/AS genotype with a time-differential geographic distribution, which evidence a constant diversification of the DENV-2 in Perú and highlight the need to have an active genomic surveillance plan for DENV that may allow to understand its dynamics and distribution patterns.