Brazil "Imported" Yellow Fever Virus From North of South America

08/18/2017 - 11h50

The genetic material analysis of the yellow fever virus responsible for the most recent outbreaks in Brazil, which started in December 2016, suggests the virus came from afar – from countries such as Venezuela and Trinidad and Tobago, at the far North of South America.

Apparently, the process began between the late 70's and early 80's, when a new strain of the virus, characterized by a small number of mutations and originally from Trinidad, became increasingly common in South America, replacing older strains of the virus.

"One of the most interesting questions this study raises is whether the replacement of strains we found are a result of a selection process or whether it depends on ecological factors not related to the evolution of the virus itself," says Gonzalo Bello, a Uruguayan researcher at Fiocruz (Fundação Oswaldo Cruz), in Rio de Janeiro. "That's a question we haven't been able to answer yet."

UPSIDE DOWN

If the data published by Bello and his colleagues in the journal "Scientific Reports" is confirmed, Brazil's position in the continental map of yellow fever outbreaks is reversed.

The Brazilian Amazon was thought to be the largest "exporter" of virus strains to neighboring countries for most of the 20th century. Now, signs indicate that Brazil was, in fact, "importing" new strains of the microscopic villain.

Translated by ANA BEATRIZ DEMARIA

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