An international research collaboration studying the genetics of Zika virus in Brazil and beyond has provided a new understanding of the disease and its rapid spread through space and time. The research has significant public health implications and has the potential to improve responses to future outbreaks.
The research published on May 24 in Nature, was led by the Universities of Birmingham and Oxford in partnership with FioCruz Bahia, the University of São Paulo, and supported by the Brazilian Ministry of Health.
By carrying out genome sequencing to understand the virus' genetic make-up, the team was able to track the spread of the virus across Brazil. The study showed that Zika's establishment within Brazil -- and its spread from there to other regions -- occurred before Zika transmission in the Americas was first discovered. By revealing this 'hidden' epidemic, the results will help scientists to better understand the link between the Zika epidemic and reports of birth defects and other diseases.
With little known at the time about the epidemiology and evolution of Zika virus, the researchers travelled 2,000 km across the northeast Brazil in June last year. The team travelled in a minibus equipped with cutting-edge mobile DNA sequencing capabilities and tested samples from more than 1,300 patients infected with the virus.
In February 2016 Zika was declared a 'Public Health Emergency of International Concern' by the World Health Organisation (WHO) in response to evidence that the infection can cause birth defects in the foetuses of infected pregnant women. The virus can be transmitted from an infected pregnant woman to her developing baby, causing problems including severe microcephaly -- a condition that results in babies being born with a smaller head size.
Read more: N. R. Faria et. al., Establishment and cryptic transmission of Zika virus in Brazil and the Americas. Nature, 2017; DOI: 10.1038/nature22401
