The world's best known Olympic historian claimed it would take something more destructive than the Zika virus to cancel the games in Rio.
Brazil is the epicentre of the rapidly spreading mosquito-borne Zika virus, which is also generating rumours that South America's first games may be called off instead of opening on August 5.
"Historically, the only times the games have been cancelled is in war - World War I and World War II," David Wallechinsky told the Associated Press.
"Other than that, nothing has done it."
Researchers have linked the virus to a birth defect that can leave newborns with long-last health and developmental problems.
Brazil's Sports Minister George Hilton issued a statement saying that cancelling the games "is not in discussion," and Rio organisers and the International Olympic Committee have repeatedly shot down the notion it's even being considered.
Wallechinsky, president of the International Society of Olympic Historians, said the only similar case was the 2014 Youth Olympics in Nanjing, China, when three athletes from west Africa were banned from competing over fears they had contracted the Ebola virus and the subsequent possibility of it spreading.
"That's the only time that disease has ever entered into it," he said.
The 1916 Olympics were called off during World War I, and four games - two summer and two winter - were cancelled between 1940 and 1944.
Two Summer Olympics were hit by partial boycotts in 1980 and 1984.
Wallechinsky said it was too late to move the games from Rio.
"A lot of money has been put into this; the athletes, the infrastructure," he said.
The Zika virus adds to other problems with South America's first Olympics, including water pollution in Rio's venues for sailing, rowing, canoeing, triathlon and open-water swimming, and deep cuts of almost 30 per cent to keep a $US2 billion ($A2.78 billion) operating budget in balance.
Only about half of the domestic tickets for the game have been sold, and organisers fear the Zika outbreak could scare off foreign tourists - particularly Americans.
