Interesting enough, although the mosquito-born disease Zika is known to cause birth defects, so far all of the American athletes that have pulled out of attending the 2016 Olympics in Rio, Brazil are men.

Arguably, a lot of these men are aware that if they plan to start a family or may start one soon, then they may be carriers of the disease. It travels through semen and can be transmitted by men to their partners. Women who are pregnant when they contract the disease may give birth to babies with birth defects.

But even if they are not planning to have a baby, the Centers for Disease Control has suggested that men abstain from sex for six months after returning from a country that has an epidemic of the disease and we know that is a lot of time to ask fellahs to be celibate.

Nonetheless, if a man catches the disease in the middle of the games, he risks being knocked out of competition because of the symptoms of the disease which include muscle pain, fever, rash and fatigue. All of these can impact a man’s athletic game. Also, there is a small risk of temporary paralysis if the virus triggers Guillain-Barre syndrome.

Today, tennis champ Serena Williams said she was sad to know so many have pulled out, but gets why still.

“At the same time, I obviously understand where they’re coming from and how they feel,” she told USA Today while in Wimbledon. Part of me feels that way, too, which is why I’m going in, you know, with a whole mindset of how do I protect myself, how do I prevent and also raise awareness for this.”

A recent Fortune article pointed out that the reason why female athletes haven’t pulled out yet is because of money. They simply do not get the same opportunities and men and cannot skip out on the potential prizes and the endorsement deals that may come if they win.

Isn’t interesting and sad at the same time.