June 22, 2016 -- Golfer Rory Mcllroy is the latest athlete to pull out of the Olympics in Brazil because of concerns about the Zika virus.
In a statement, the 27-year-old said, "My health and my family's health comes before everything else.
"Even though the risk of infection from the Zika virus is considered low, it is a risk nonetheless and a risk I am unwilling to take."
McIlroy, a four-time major champion, was set to represent Ireland in Rio.
Brazil, which is hosting the 2016 Olympic Summer Games in August, has been hard hit by Zika. More than 1,500 babies have been born with microcephaly or other birth defects suspected to be related to Zika infections, according to the World Health Organization.
Two other golfers -- Vijay Singh and Marc Leishman -- have already pulled out of the Olympics because of concerns about the virus.
The British long jumper Greg Rutherford has had his sperm frozen before the competition in Rio due to worries about Zika. In an interview with the Standard Issue magazine, his partner Susie Verrill said: "We’d love to have more children, and with research in its infancy, I wouldn’t want to put myself in a situation which could have been prevented."
Researchers don’t yet know how long the Zika virus remains in a man’s semen after infection. The CDC has recommended men diagnosed with Zika consider using condoms or not having sex for at least 6 months.
Sports groups were particularly disappointed by Mcllroy's decision, because 2016 marks the return of golf as a recognized Olympic sport after a 112-year absence. It last featured in the 1904 Games in St. Louis, MO.
'A Unique Set of Circumstances'
The International Golf Federation said it was disappointed with Mcllroy's decision to withdraw, but said it recognized "that some players will have to weigh personally a unique set of circumstances as they contemplate their participation in golf’s historic return to the Olympic Games in Rio de Janeiro, with the Zika virus foremost among them".
The Olympic Council of Ireland says it has "total confidence that the Games will be safe for all athletes," but it's down to the individual to make the final decision.
"Rory Mcllroy has made a personal decision not to attend the Rio Olympics,” says Jimmy Whitworth, professor of international public health at the London School of Hygiene and Tropical Medicine, in a statement. “That is as it should be -- we do not know his personal circumstances and we should respect his decision.
“Golf courses would not be particularly dangerous places for getting infected with Zika,” he says. The mosquitoes that spread Zika -- Aedes aegypti and Aedes albopictus -- live near houses and don’t fly far from breeding sites, he says.
"For most people, Zika virus causes a mild illness, often not even clinically apparent,” Whitworth says “If you do become ill, you will be fully recovered in a week or so. Rarely complications such as Guillain-Barré syndrome may occur, but we should put this into perspective. This syndrome is as common or commoner after ordinary gut infections, such as Campylobacter, which are likely to be more common in Rio than Zika anyway.
"The most credible estimates suggest no more than 10-20 infections with Zika among the half a million athletes and visitors going to Brazil for the Olympics."
'Little to Worry About'
If McIlroy is planning on becoming a father in the next year or so, his decision is “perfectly reasonable,” says Derek Gatherer, lecturer in the Division of Biomedical and Life Sciences at Lancaster University.
"On the other hand, if he is not going to become a father any time soon, he has little to worry about, provided he takes the usual precautions for tropical countries.”
Jonathan Ball, professor of molecular virology at the University of Nottingham, says: "Obviously I don’t know the reasons for this decision, but it does strike me as being extreme. The chances of being infected by Zika virus is low, especially if you protect yourself from mosquito bites by covering up and using a good insect repellent."