How HIV spread across North America (image) University of Arizona Share Print E-Mail Caption After HIV moved from Africa to the Caribbean, it first spread to New York and subsequently to different locations in the U.S. By constructing evolutionary trees of the various HIV strains as far back as the 1970s, the researchers found evidence that the virus had been circulating under the radar for ten years before the outbreak in the US was recognized. Credit Worobey et al./Nature Usage Restrictions This visual may only be used in conjunction of reporting/posting of this news release. Credit must be stated as indicated. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.