Last November, actor Charlie Sheen confirmed on a national TV show that he is HIV-positive. Researchers found that his decision to go public resulted in extensive HIV and AIDS awareness that could lead to more prevention initiatives.

In the U.S., the so-called "Charlie Sheen effect" garnered the highest documented numbers of HIV searches on Google. Sheen's announcement also resulted in the highest levels of HIV coverage in domestic news to date.

Study author John Ayers, Ph.D., from the San Diego State University, California, said Sheen's announcement about his HIV diagnosis was a "potential earth-shaking event" for the disease's prevention in the U.S. Using a Bloomberg Terminal, Ayers led a team in the analysis of HIV and HIV-prevention engagement in news coverage and Google Trends in the last 12 years.

Since 2004, HIV news reports spiraled down from 67 per 1,000 stories to just 12 per 1,000 stories last year. But when Sheen went public on a national TV show, reporters saw a 265 percent surge in the HIV and HIV-related news coverage.

On the day Sheen announced his HIV diagnosis, Google searches with the word "HIV" recorded around 2.75 million more than the usual number of online inquiries. Google searches with the words "HIV symptoms," "condoms," and "HIV testing" resulted in 1.25 more inquiries than expected on that day.

In 1991, NBA's Magic Johnson announced a similar diagnosis. Unlike then, almost everyone have smartphones now and can easily search for HIV with just a few clicks. Co-author Eric Leas from the university added that social media helped increase the effect beyond the initial broadcast on television.

"The day of Sheen's disclosure was the biggest abrupt HIV event in our existence," said managing editor JD Davids of TheBody.com, a 25-year-old HIV/AIDS awareness website. "It was our largest traffic day ever, by far."

Ayers said that while revelations about HIV status and all diagnoses are terrible, Sheen's announcement could be beneficial to the public health by helping increase awareness about HIV and its prevention. The study on the "Charlie Sheen effect" was published in the Journal of the American Medical Association (JAMA) Internal Medicine on Monday, Feb. 22.