Possible Emergence of Zika Virus of African Lineage in Brazil and the Risk for New Outbreaks

Abstract

In 2015, an outbreak of Zika virus (ZIKV) infection caused a disproportionate increase in the number of cases of microcephaly in Brazil (de Oliveira et al., 2017). Although two major ZIKV lineages referred to as African lineage (ZIKVAF) and Asian lineage (ZIKVAS) have been identified, phylogenetic and genomic analyses pointed to those cases as caused by a ZIKVAS (Faria et al., 2017). This link led scientists to not target ZIKVAF on their investigations. Due to this, information about ZIKVAF circulation in Brazil has been underestimated as well as its epidemic potential. Recently, a study published by Kasprzykowski et al. (2020) identified ZIKVAF present among Brazilian ZIKV sequences. ZIKVAF was identified in non-human primates (NHPs) and mosquitoes in the South and Southeast Brazilian regions, respectively ( Figure 1 ) (de Almeida et al., 2019– Preprint publication; Alencar et al., 2021). At the same time, Aubry et al. (2021) showed ZIKVAF being more transmissible in mosquitoes and more lethal in mice when compared to ZIKVAS. In addition, it was suggested that there was a high epidemic potential of ZIKVAF. Since South and Southeast Brazilian regions are geographically distant (> 1,500 km) and climatically different, and the ZIKVAF was found from different sources, here we raise and bring concerns about the circulation of this lineage in Brazil and the risk it might represent as the cause of a new outbreak of disease in humans potentially associated with birth defects. Open in a separate window Figure 1 Incidence per 100,000 inhabitants of Zika cases in Brazil reported in 2016. Color gradient representing high (darker blue) to low ZIKV incidence (lighter blue). The Brazilian states where ZIKVAF was identified in sylvatic area are also highlighted. Zika virus incidence data were recovered from Brazil Ministry of Health (2018). AC, Acre; AL, Alagoas; AP, Amapa; AM, Amazonas; BA, Bahia; CE, Ceara; DF, Distrito Federal; ES, Espirito Santo; GO, Goias; MA, Maranhao; MT, Mato Grosso; MS, Mato Grosso do Sul; MG, Minas Gerais; PA, Para; PB, Paraiba; PR, Parana; PE, Pernambuco; PI, Piaui; RJ, Rio de Janeiro; RN, Rio Grande do Norte; RS, Rio Grande do Sul; RO, Rondonia; RR, Roraima; SC, Santa Catarina; SP, Sao Paulo; SE, Sergipe; TO, Tocantins.