Molecular Characterization of Dengue Type 2 Outbreak in Pacific Islands Countries and Territories, 2017–2020

Catherine Inizan (1) , Olivia O'Connor (1) , George Worwor (2) , Talica Cabemaiwai (3) , Jean-Claude Grignon (4) , Dominique Girault (1) , Marine Minier (1) , Matthieu Prot (5) , Valentine Ballan (1) , George Junior Pakoa (2) , Jean-Paul Grangeon (6) , Philippe Guyant (7) , Christelle Lepers (8) , Daniel Faktaufon (3) , Aalisha Sahukhan (3) , Onofre Edwin Jr. Merilles (8) , Ann-Claire Gourinat (9) , Etienne Simon-Loriere (5) , Myrielle Dupont-Rouzeyrol (1)

1 URE-DA - Dengue et Arbovirose
2 Ministry of health [Vanuatu]
3 Fiji Centre for Communicable Disease Control [Suva, Fidji]
4 Hôpital de Sia [Wallis]
5 Génomique évolutive des virus à ARN - Evolutionary genomics of RNA viruses
6 Direction des affaires sanitaires et sociales de Nouvelle-Calédonie
7 WHO Country Liaison Office [Port Vila, Vanuatu]
8 SPC - Pacific community
9 Centre hospitalier territorial Gaston-Bourret [Nouméa]

Dengue virus (DENV) serotype-2 was detected in the South Pacific region in 2014 for the first time in 15 years. In 2016-2020, DENV-2 re-emerged in French Polynesia, Vanuatu, Wallis and Futuna, and New Caledonia, co-circulating with and later replacing DENV-1. In this context, epidemiological and molecular evolution data are paramount to decipher the diffusion route of this DENV-2 in the South Pacific region. In the current work, the E gene from 23 DENV-2 serum samples collected in Vanuatu, Fiji, Wallis and Futuna, and New Caledonia was sequenced. Both maximum likelihood and Bayesian phylogenetic analyses were performed. While all DENV-2 strains sequenced belong to the Cosmopolitan genotype, phylogenetic analysis suggests at least three different DENV-2 introductions in the South Pacific between 2017 and 2020. Strains retrieved in these Pacific Islands Countries and Territories (PICTs) in 2017-2020 are phylogenetically related, with strong phylogenetic links between strains retrieved from French PICTs. These phylogenetic data substantiate epidemiological data of the DENV-2 diffusion pattern between these countries.

Keywords: Pacific; dengue; molecular evolution; phylogeny

Domains: Life Sciences [q-bio]; Microbiology and Parasitology; Virology; Life Sciences [q-bio]; Biodiversity; Systematics, Phylogenetics and taxonomy

Catherine Inizan, Olivia O'Connor, George Worwor, Talica Cabemaiwai, Jean-Claude Grignon, et al.. Molecular Characterization of Dengue Type 2 Outbreak in Pacific Islands Countries and Territories, 2017–2020. Viruses, 2020, 12 (10), pp.1081. ⟨10.3390/v12101081⟩. ⟨pasteur-03039686⟩