Multifoci and multiserotypes circulation of dengue virus in Senegal between 2017 and 2018

Abstract

Background Dengue fever is a mosquito born disease associated with self-limited to life threatening illness. First detected in Senegal in the nineteenth century, and despite its growing incidence this last decade, significant knowledge gaps exist in our knowledge of genetic diversity of circulating strains. This study highlights the circulating serotypes and genotypes between January 2017 and December 2018 and their spatial and temporal distribution throughout all regions of Senegal. Methods We used 56 dengue virus (DENV) strains for the analysis collected from 11 sampling areas: 39 from all regions of Senegal, and 17 isolates from Thiès, a particular area of the country. Two real time RT-qPCR systems were used to confirm dengue infection and corresponding serotypes. For molecular characterization, CprM gene was sequenced and submitted to phylogenetic analysis for serotypes and genotypes assignment. Results Three dengue virus serotypes (DENV-1–3) were detected by all used methods. DENV-3 was detected in 50% (28/56) of the isolates, followed by DENV-1 and DENV-2, each representing 25% (14/56) of the isolates. DENV-3 belongs to genotype III, DENV-1 to genotype V and DENV-2 to Cosmopolitan genotype. Serotype 3 was detected in 7 sampling locations and a co-circulation of different serotypes was observed in Thiès, Fatick and Richard-toll. Conclusions These results emphasize the need of continuous DENV surveillance in Senegal to detect DENV cases, to define circulating serotypes/genotypes and to prevent the spread and the occurrence of severe cases.

Full genome analysis of circulating DENV‐2 in Senegal reveals a regional diversification into separate clades

“…20 Since 2017 to date recurrent dengue outbreaks with co-circulation of many serotypes (DENV-1-3) are reported in Senegal. 21 According to data from WHOCC for arboviruses and hemorrhagic fever viruses, DENV-2 is continuously circulating in Senegal since 2014 (unpublished data); interestingly during all reported outbreaks since 2017, DENV-2 was identified as the dominant serotype only during epidemics in Rosso in 2018 (Northern Senegal). 32 Knowing that determinants of DENV fitness, pathogenesis, and disease outcome are multifactorial, our present study results revealed the circulation of DENV-2 strains belonging to two different clades of DENV-2 cosmopolitan genotype in Senegal in 2018.…”

“…20 Since then, dengue was considered endemic in Senegal, with a regular shift in circulating serotypes leading to recurrent epidemics. 21,22 In more recent years, we observed an increased incidence of dengue characterized by multifoci and the co-circulation of several serotypes. 21 Interestingly, viral endemicity may facilitate the accumulation of genetic diversity and could be linked to disease spread, severity, and outcomes.…”

“…21,22 In more recent years, we observed an increased incidence of dengue characterized by multifoci and the co-circulation of several serotypes. 21 Interestingly, viral endemicity may facilitate the accumulation of genetic diversity and could be linked to disease spread, severity, and outcomes. 22 In 2018, four dengue virus outbreaks occurred in Senegal.…”

Full Genome Analysis of Circulating DENV-2 in Senegal Reveals a Regional Diversification Into Separate Clades <strong> </strong><strong> </strong>

“…Dengue is hyperendemic (Dieng et al, 2021) in Senegal and this is known to be associated with a cyclic behaviour of serotype replacement leading to periodic epidemics (Laiton-Donato et al, 2019). Since 2017 a growing dengue incidence is noticed in Senegal with multifoci and multiserotypes circulation (Dieng et al, 2021).…”

“…Dengue is hyperendemic (Dieng et al, 2021) in Senegal and this is known to be associated with a cyclic behaviour of serotype replacement leading to periodic epidemics (Laiton-Donato et al, 2019). Since 2017 a growing dengue incidence is noticed in Senegal with multifoci and multiserotypes circulation (Dieng et al, 2021). Interestingly, endemic behaviour may facilitate accumulation of genetic diversity and could be linked to disease spread, severity and outcomes (Laiton-Donato et al, 2019).…”