Singapore confirms Zika spread; U.S. and other countries issue travel warnings Zika was first discovered in Uganda in 1947. It caused clusters of human infections from the 1960s to 1980s across Africa and Asia, according to the World Health Organization. The outbreak in the Americas was caused by a Zika strain from Asia, possibly carried to Brazil through travel to a sporting event. Many experts believe […]
Singapore confirms Zika spread; U.S. and other countries issue travel warnings he outbreak in the Americas was caused by a Zika strain from Asia, possibly carried to Brazil through travel to a sporting event. Many experts believe once infected, Zika produces lifelong immunity. “Unfortunately, it is not clear the level of immunity that is currently in Asia,” said Alessandro Vespignani of Northeastern University in Boston.