Pro golfer Jason Day has joined the growing list of of athletes who will not go to the summer Olympics in Rio de Janeiro in August.

All of the athletes who have withdrawn thus far are golfers except for one.

Zika is mainly carried by mosquitos. Common symptoms are rash, fever, joint pain and conjunctivitis, according to the Centers for Disease Control and Prevention. The virus is rarely fatal.

Brazil is one of a few countries experiencing a Zika virus outbreak, according to the CDC, which has provided a translation guide for those attending the Rio games. Phrases included in the guide include, "I feel sick," "fever," "rash" and more.