The Zika virus may have circulated undetected for up to a year in certain regions before public health officials could identify it, according to a recent study conducted by the National Institute of Allergy and Infectious Diseases (NIAID) and the National Institutes of Health (NIH).
NIH researchers first reconstructed the virus’ dispersal by sequencing Zika genetic material collected from hundreds of patients throughout 10 different countries and territories. In total, they amassed a database comprised of 110 complete or partial Zika genomes, along with 64-already published genomes.
Due to changes to the viral genome that accumulated as the virus moved throughout different populations, the researchers found that Zika spread rapidly upon its initial introduction in Brazil, which likely occurred in 2013.
In early-to-mid 2015, the virus separated into at least three different subtypes which were found in Colombia, Honduras, and Puerto Rico. A fourth subtype was also found in the Caribbean and the continental United States.
NIH said the results might have a direct impact on public health, as a clear understanding of the genetic changes to pathogens that can occur during emerging outbreaks will be key to informing disease surveillance and development of diagnostic tests.