The Rio Olympic Games should be postponed or moved "in the name of public health" over the Zika outbreak in Brazil, more than 100 prominent doctors and professors said in an open letter to the World Health Organisation (WHO). "We make this call despite the widespread fatalism that the Rio 2016 Games are inevitable or 'too big to fail,'" the writers said on Friday in the letter addressed to WHO Director-General Margaret Chan. "Our greater concern is for global health. The Brazilian strain of Zika virus harms health in ways that science has not observed before." However, the WHO released a statement saying that based on its current assessment, "cancelling or changing the location of the 2016 Olympics will not significantly alter the international spread of Zika virus." The organisation noted that Brazil has been the epicentre of the virus and one of almost 60 countries that have reported continuing transmission of Zika by mosquitoes, CNN reported. "People continue to travel between these countries and territories for a variety of reasons. The best way to reduce risk of disease is to follow public health travel advice," the WHO said. The International Olympic Committee has said it has no plans to cancel or postpone the Games. The officials in the letter stated the Zika virus has "more serious medical consequences than previously known" and has worsened in the Rio area despite widespread mosquito treatment programmes. "It is unethical to run the risk," the letter said, adding "It is therefore imperative that WHO conducts a fresh, evidence-based assessment of Zika and the Games, and its recommendations for travellers." The Olympics are scheduled to begin on August 5-21. More than 500,000 people are expected to travel to Brazil from around the world.