With the Olympic games scheduled for later this year in Brazil, athletes and national Olympic committees across the globe are expressing concern about the Zika virus, which is spread by mosquitoes.
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George Boville, an Olympic bronze medalist swimmer for Trinidad and Tobago in the 200 meter individual medley and two-time world champion, told ABC News that he was worried about going to Brazil, where the outbreak of the Zika virus in the Americas started.
"It is definitely a concern," he told ABC News via Twitter. By the time of the Olympic games, "it should be rampant."
The New Zealand Olympic Committee and the Australian Olympic Team Committee have already told their athletes to take protective measures.
The New Zealand Olympic Committee said they are abiding by government recommendations, which at this point advise "expectant mothers or those planning pregnancy do not travel to areas with the Zika virus present."
"We would support any athlete or support staff member in their decision to not attend the games if this were the case," the committee said in a statement last week.
The Australian Olympic Committee said they are advising all athletes to wear long sleeves and that any team member who is "pregnant at the time of the Games need to consider the risks very carefully before deciding whether to proceed with travel to Brazil."
American wrestler Adeline Grey told reporters at a test event on Sunday at Rio's Olympic Park that she didn't plan to skip the games, but that if she were pregnant she would reconsider participating.
"If I was planning to have a child next month, I would be extremely uneasy about this," Gray said, according to the Associated Press. "Maybe that would have changed my decision" to come to Rio for the test event.
The International Olympic Committee released a note on Friday to all Olympic committees outlining medical advice.
"We remain confident that there will be a safe environment for successful and enjoyable Olympic Games in Rio de Janeiro," the IOC said in the statement.
The United States Olympic Committee officials said they are most concerned about the well-being of athletes and staff going to the games.
"We continue to closely monitor the situation through the CDC and have ongoing contact with the International Olympic Committee, the organizing officials in Rio, the World Health Organization and infectious disease specialists with expertise in tropical diseases, including the Zika virus," the USOC said in a statement.
The Zika virus is characterized by mostly mild symptoms, including fever, rash and fatigue. However, it has been associated with a worrying rise in a dangerous birth defect called microcephaly, where an infant is born with an abnormally small head. It has been known to be associated with developmental delays and seizures.
Rio 2016's communications director, Mario Andrada, said there currently was no measurable reaction in ticket-holders, according to Reuters.
"Tickets have not been returned nor trips canceled," he said, according to Reuters.
Pregnant Olympic athletes are a rare occurrence, but multiple women have reportedly competed while they were unknowingly pregnant. At the 2012 Summer Olympics, Kerri Walsh Jennings was five weeks pregnant when she won the gold medal, according to ESPN.com.
And many of those who travel to the Olympics are the family members of the athletes.