Zika virus in the Americas: Early epidemiological and genetic findings

TLDR

The Zika virus outbreak in Brazil has raised concern due to its association with rare birth defects and neuropathology. The authors performed a phylogenetic analysis of Zika virus genomes. The study inferred a single introduction of Zika to the Americas in mid‑2013, roughly a year before it was reported, and associated this timing with heightened travel during Brazilian cultural events and with microcephaly cases occurring at week 17 of pregnancy. Published in Science, p.

Abstract

Zika virus genomes from Brazil The Zika virus outbreak is a major cause for concern in Brazil, where it has been linked with increased reports of otherwise rare birth defects and neuropathology. In a phylogenetic analysis, Faria et al. infer a single introduction of Zika to the Americas and estimated the introduction date to be about May to December 2013—some 12 months earlier than the virus was reported. This timing correlates with major events in the Brazilian cultural calendar associated with increased traveler numbers from areas where Zika virus has been circulating. A correlation was also observed between incidences of microcephaly and week 17 of pregnancy. Science , this issue p. 345