PHYLODYNAMICS OF ENTEROVIRUS A71 IN SOUTH AMERICA

LEMA C; TORRES C; PALACIOS G; CISTERNA D

Workshop; 28th International Bioinformatics Workshop on Virus Evolution and Molecular Epidemiology (VEME); 2024

Enterovirus A71 (EVA71) are the cause of a wide spectrum diseases, including neurological disorders. Geno-groups B and C are currently in circulation, and based on their genetic similarities were subdivided into B0 to B5 and C1 to C5. C1 and C2 are chief found in Europe. Despite this, the global and regional dispersion patterns, especially in South America, are still largely unknown. As part of epidemiological surveillance of acute flaccid paralysis, 11 isolates of EVA71 from stool samples were collected during 2017 to 2018 from different provinces of Argentina. The whole genome for all the isolates were obtained by NGS technology.We try to establish the viral geno-groups by phylogenetic analysis in VP1 region and through Bayesian coalescent analyses estimate the date of introduction to the country and from where it was introduced. Phylogenetic reconstruction by maximum likelihood showed seven Argentinean sequences belong to C1 and the others four to C2. Four sequences from Peru (the unique sequences available from South America) belong to C1. C1 Argentinean sequences belong to two groups. The estimated start date of diversification for each group were in June 2015 (95% HPD 2014.95-2015.98) from France (pp=0.78) and December 2014 (95% HPD 2015.85-2013.99) from Germany (pp=1) respectively. The sequences from Peru would have started its diversification in March 1998 (95% HPD 1997.8 – 1999.1) from Germany (pp=0.75). C2 Argentinean sequences start its diversification on Jun 2010 (95% HPD 2008.81-2011.73) from France (pp=1). The overall substitution rate was estimated as 3.25 10-3 substitution/site/year (s/s/y) (95% HPD 2.9 – 3.5 10-3) for C1 and 2.70 10-3 s/s/y (95% HPD 2.4 – 3.0 10-3) for C2. All these estimates, however, are affected by the lack of a specific and routine surveillance of EVA71 in the region. This is the first report that describes the introduction of EVA71 in South America. More studies will be required to deepen the knowledge about their dispersion especially in the region.