When Charlie Sheen went on national television last fall and told the world he had HIV, he said he hoped his predicament would prompt others to protect themselves against the virus that causes AIDS.
They certainly did. A research letter published Monday in the journal JAMA Internal Medicine says Google searches about HIV hit an all-time high after the former "Two and a Half Men" star made his announcement on Nov. 17.
On that day, Americans Googled "HIV" about 2.75 million times more than researchers would have expected if Sheen hadn't revealed his medical news.
Among those Web searches, about 1.25 million also included terms related to condoms, HIV symptoms and testing. The study authors consider these searches "directly relevant to public health," according to their report.
Sheen disclosed his HIV status in an interview with Matt Lauer on NBC's "Today" show. He said he had become infected four years earlier – though he was not "entirely sure" how it happened – and that he paid millions of dollars to a prostitute who threatened to go public with pictures of his anti-retroviral medications.
"I have a responsibility now to better myself and to help a lot of other people," Sheen told Lauer. "Hopefully with what we're doing today, others may come forward and say, 'Thanks, Charlie, thanks for kicking the door open.'"
To see if they did, researchers examined all Google searches related to HIV that occurred between Jan. 1, 2004, and Nov. 24, 2015. That allowed them to estimate how many times Google users would have searched for "HIV" if Nov. 17 had been a typical Tuesday.
The team, led by San Diego State University public health expert John Ayers, calculated that the actual number of searches was 417% higher than would have been expected, according to the report.
In addition, the researchers found that searches about condoms were 72% more common than usual in the first 24 hours after Sheen's news broke; searches about HIV testing were 214% higher than usual; and searches about HIV symptoms jumped by 540%.
Altogether, Sheen's interview was followed by "the greatest number of HIV-related Google searches ever recorded in the United States," according to the study.
The researchers have a name for this sudden interest in HIV: the "Charlie Sheen effect." That is an apparent reference to the "Katie Couric effect," a documented increase in screening colonoscopies after the journalist had one on live TV to raise awareness about colon cancer prevention.
But Google searches are only the beginning, and public health experts should conduct further studies to see whether this spike in online research translates into a higher rate of HIV testing, the study authors said.
"While no one should be forced to reveal HIV status, Sheen's disclosure may benefit public health by helping many people learn more about HIV infection and prevention," they wrote. "More must be done to make this benefit larger and lasting."
That point was echoed in a short commentary by Dr. Mitchell Katz, director of the Los Angeles County Department of Health Services.
The key question for health experts, he wrote, is how to take advantage of the public's "prurient interest in the lives of prominent persons" to educate people about important medical issues.
It's impossible to predict when the next bombshell revelation will occur. But when it does, it's a safe bet that a celebrity-obsessed culture will flock to the Internet in search of all the detail it can get.
"The job of public health is to be certain that the right information is easily available when people seek it," Katz wrote. "We can provide more effective messages about public health if we adapt traditional methods of health education to our increasingly social media-driven world and make sure the messages are available in advance of the next celebrity disclosure."
Sheen, for his part, was gratified to learn that his personal story had indeed become a teachable moment. Here's how he expressed his feelings on Twitter:
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