(Reuters) - World number one Jason Day became the latest top golfer to withdraw from August's Rio de Janeiro Olympic Games because of the Zika virus on Tuesday. Golf is returning to the Olympics for the first time since 1904, but a number of big names, including four-times major champion Rory McIlroy, Fiji's Vijay Singh and Charl Schwartzel of South Africa, have also pulled out due to Zika concerns. The mosquito-borne Zika virus, which the World Health Organization says is spreading rapidly in the Americas, can cause crippling defects in babies and has been linked to the neurological disorder Guillain-Barre in adults. More...