South African Jaco Van Zyl, who sat out the year's last major, the PGA Championship, to prepare for the Olympics, says the world's top-ranked golfers are using the Zika virus as an excuse to dodge the Rio Games.

World number one Jason Day of Australia, American world number two Dustin Johnson and number three Jordan Spieth and fourth ranked Northern Irishman Rory McIlroy all removed their names from Olympic consideration citing the risk of contracting the Zika virus.

U.S. health officials have concluded that infections by the mosquito-borne Zika virus in pregnant women can cause microcephaly, a birth defect marked by small head size that can lead to severe developmental problems in babies.

The World Health Organization has also warned there is strong scientific consensus that Zika can also cause Guillain-Barre, a rare neurological syndrome that causes temporary paralysis in adults.

"Honestly, I can't feel that the Zika virus would be their reason not to go, the Zika virus is in Florida," said Van Zyl, number 71 in the world ranking.

"I think they have got other reasons for not wanting to participate and the Zika virus is a very convenient way for them to get out of it."

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Making its return to the Olympic program for the first time in over a century, golf has been hard hit by drop outs.

Major winners Adam Scott of Australia, Fiji's Vijay Singh and South Africans Louis Oosthuizen and Charl Schwartzel will also be among the absentees for the Aug. 11-14 Olympic competition.

Oosthuizen and Schwartzel's decision to skip the Games, however, opened the door for Van Zyl, who made going for gold a top priority and rearranged his schedule to prepare for the Olympics.

"If I can choose one (a major championship win or an Olympic gold medal) I would definitely take the gold," said the 37-year-old, who was runner-up at the Turkish Airlines Open last year. "The reason being that there are four majors every year and one Olympic gold medalist in 112 years.

"To get an opportunity and let it pass by doesn't make much sense to me."