SAN DIEGO - Charlie Sheen's public disclosure last fall that he was HIV-positive resulted in the greatest number of Google searches related to the disease ever recorded in the U.S. on a single day, according to a San Diego State University-led study released Monday.
"Charlie Sheen's disclosure was a potential earthshaking event for HIV prevention in the United States," said John Ayers, a research professor at the SDSU Graduate School of Public Health.
Ayers tracked news coverage of Sheen's announcement and subsequent Google queries on subjects like condoms and HIV prevention. His study was published in Monday's edition of the Journal of the American Medical Association.
Ayers and Benjamin Althouse, a research scientist at the Institute for Disease Modeling and the Santa Fe Institute, found a 265 percent increase in the number of news stories that mentioned HIV on the day of Sheen's announcement, even though coverage of the virus that causes AIDS had been in decline.
An additional 6,500 stories were reported on Google News alone, which placed Sheen's disclosure among the top 1 percent of historic HIV-related media events, according to the researchers.
They said Sheen's Nov. 17 disclosure also corresponded with the greatest number of HIV-related Google searches ever recorded in this country on a single day, about 2.75 million more than normal, based on previous trends. Searches about condoms, symptoms or resting increased by 1.25 million.
In relative terms, HIV searches were 417 percent higher than expected the day of Sheen's disclosure. Condom searches -- such as "buy condoms" -- increased 75 percent.
Queries like "signs of HIV" and "find HIV testing" increased 540 and 214 percent, respectively, the day of Sheen's disclosure. They remained higher for three days, according to the study.
"While no one should be forced to reveal their HIV status and all diagnoses are tragic, Sheen's disclosure may benefit public health by potentially helping many learn more about HIV and HIV prevention," Ayers said.
He said public health officials missed a big opportunity by not mentioning Sheen in public outreach, though he noted that the actor is a controversial figure.
Eric Leas, a student of health communication at UC San Diego and study co-author, said celebrity disclosures are not new to HIV, with actor Rock Hudson and basketball star Magic Johnson being noteworthy examples.
But heightened Internet use makes Sheen's announcement different.
"With Sheen, unlike with Magic Johnson for instance, we have smartphones in our pockets that we can easily use to learn about HIV within seconds with a single search or click," Leas said. "At the same time, social media can expand the effect of Sheen's disclosure beyond the initial television broadcast as networks form around celebrities."
Seth Noar, a University of North Carolina expert on HIV prevention media campaigns, also contributed to the study.