The White House was not an accurate source of information when Woodrow Wilson fell ill with the Spanish flu. Photo / Getty Images
A deadly pandemic raged across the world. Millions had been infected. And suddenly the US president himself was hit by the virus.
The year was 1919. Woodrow Wilson had been laid low by the Spanish flu in Paris, where he and other world leaders were negotiating the post-first world warsettlement in Europe.
In public, the White House played down the illness as a mere cold. In reality, Wilson was "violently sick" with influenza, his doctor wrote in private.
A hundred years later, echoes of Wilson's experience have returned as Donald Trump has become infected with coronavirus. His doctor said on Friday Mr Trump was "fatigued but in good spirits". He would spend a few days at Walter Reed military medical centre "out of an abundance of caution", the White House said.
Mr Trump is the latest in a long line of American presidents to suffer ill health in office. The history of illness in US presidents is largely one of intense secrecy, and occasionally flat out lies.
Wilson would later in 1919 suffer a stroke that partially paralysed him and left him unable to perform the duties of president without the help of his second wife Edith.
"His wife was essentially running the White House," said Mr Petriello, who chronicled the impact of disease on the presidency in A Pestilence on Pennsylvania Avenue.
The imperative for secrecy has included denying the truth even when revealed, most notably in 1893 when Grover Cleveland had surgery to remove a cancerous lump in his mouth while in office.
The procedure was carried out on a friend's yacht off the coast of New York, without the vice-president's knowledge. The cover story later spun was he had dental surgery for a toothache.
A journalist, EJ Edwards, published a story about what actually happened. "The White House flat out denied it," said Matthew Algeo, author of a book about Cleveland's surgery called The President Is a Sick Man.
Mr Algeo said that Cleveland at the time had a reputation for honesty, so Edwards was discredited and the president's denial was widely believed. "He kind of cashed in all his honesty chips on this one big lie."
Only years later, in 1917 years after Cleveland had died, would one of his doctors admit Edwards had gotten it right.
"It was a very successful example of a president covering up," said Mr Algeo. "The president's physician, he's not obliged to tell me and you and the American public what's going on. He's obliged to respect the wishes of the patient."
The question of who is in control of the US government if the president is stricken was not firmly resolved until the late 1960s, when the 25th amendment specified that the vice-president becomes the acting chief executive.
On the two occasions George W Bush had a colonoscopy while in office, he formally transferred power to his vice-president, Dick Cheney, for the time of the procedure. Both times the public was informed in advance.
The modern era of relative transparency about a president's health has its origins with Dwight Eisenhower, who suffered a heart attack in 1955 while in office.
After the administration initially misled reporters about what happened, it reversed course with a torrent of information about his condition — including news of a successful bowel movement.
A decade or so earlier, Franklin Delano Roosevelt had died in office of a cerebral haemorrhage shortly after being elected to a fourth term — he was the most recent president to die in office of natural causes.
Roosevelt had needed the use of a wheelchair after contracting polio in his 30s, though he went to great lengths to avoid public awareness of his incapacity while campaigning for president and then in office.
"He did a lot to mask his illness from the public," said Louis Picone, author of a history on presidential deaths called The President is Dead. "He would have people standing right next to him propping him up."
Roosevelt's health would deteriorate dramatically as president as he suffered from heart disease. When he ran for re-election in 1944, a doctor who examined him recorded in a memo that Roosevelt would not see out his fourth term. The memo would not be published until the century was out.