Last updated June 6, 2017 at 1:24 pm
DNA can hold a lot of revealing secrets, new research reveals the travel path of Zika virus.
Three studies into the DNA of the Zika virus reveal its origins in northeastern Brazil and its rapid spread to neighbouring countries. One of the papers also reveals that Zika spread into the USA four times from the Caribbean rather than straight from South America. This collection of monumental research examined close to 200 new Zika virus genome sequences.
Zika virus was first identified in Africa in 1947 and named after the forest where it was found but it came to the world’s attention in the lead up to the 2016 Olympic Games in Brazil. An outbreak of the virus, which is spread by mosquitoes, occurred in the months before the Games causing great concern for its spread internationally through athletes and spectators.
Zika infections in humans most often present no obvious symptoms but can develop into a mild fever. However, infection during pregnancy causes microcephaly and other brain malformations in some babies and infection in adults has been linked to Guillain–Barré syndrome.
The three papers published today in the journal Nature all look to the DNA recovered from Zika-infected people to reconstruct the history and spread of the Brazilian outbreak.
One paper suggests that the virus was circulating in northeast Brazil by late 2013 or early 2014.
A second paper observed the rapid expansion of the epidemic within Brazil and multiple introductions to other geographic regions and neighbouring countries.
The third paper shows that the Zika virus was introduced to Florida at least four times and that most of these introductions were linked to travel from the Caribbean. These researchers also claim that areas in southern Florida are particularly vulnerable to Zika virus introductions.
All three papers show that the Zika virus circulated undetected for many months before the outbreak was identified.
By analyzing genomes generated as part of the study, researchers confirmed that the Zika virus was present in affected countries well before the first confirmed cases were detected. Credit: Broad Institute
It is hoped that this better understanding of how the Brazilian outbreak started and developed will provide a useful tool in restricting the future spread of this disease.
- Link to original research articles: