Researchers are studying the effect of the actor’s public announcement to see if it can be duplicated in other cases.

When actor Charlie Sheen announced his HIV-positive status on NBC’s Today Show, the world listened in stunned silence.

Scientists are now investigating the influence of his disclosure on levels of HIV testing.

About 1.2 million people in the United States are currently living with HIV. The Centers for Disease Control and Prevention (CDC) estimate that, of those, 1 in 8 do not know that they have the disease.

Because of the stigma attached to HIV, any event that prompts people to get tested must be capitalized upon, officials say.

Charlie Sheen’s television declaration was one such event.

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Sheen found fame acting in such films as “Platoon” and “Young Guns” as well as the television series “Two and a Half Men” and “Spin City.”

Following his interview in November 2015, Sheen became one of the most prominent celebrities who is publicly HIV-positive.

His interview preceded a huge spike in online search queries for topics regarding HIV prevention and testing. This surge appeared even though neither Sheen nor official health agencies called for action.

In April 2016, researchers from San Diego State University Graduate School of Public Health in California published a study in JAMA Internal Medicine. Their investigation examined the boost in internet traffic around the subject of HIV tests.

They documented a rise in Google searches that included terms such as “tests,” “testing,” or “test,” and “HIV.”

Led by research professor John W. Ayers, the team concluded that “Sheen’s disclosure may benefit public health by helping people learn more about HIV infection and prevention.”

One year later, Ayers set out to discover whether the public’s behavior matched the jump in Internet activity.

His team’s findings are published this week in the journal Prevention Science.

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OraQuick is the only rapid HIV test kit available for home use in the U.S.

Ayers’ analysis centered on sales data for this product to see whether or not they correlated with the uptick in search traffic.

Study co-author Eric Leas explains, “Our strategy allowed us to provide a real-world estimation of the ‘Charlie Sheen effect’ on HIV prevention and contrast that effect with our past formative assessment using Internet searches.”

During the week of Sheen’s announcement, OraQuick sales almost doubled, hitting an all-time high. They remained significantly elevated for three weeks, with “8,225 more sales than expected.”

“In absolute terms, it’s hard to appreciate the magnitude of Sheen’s disclosure. However, when we compared Sheen’s disclosure to other traditional awareness campaigns the ‘Charlie Sheen effect’ is astonishing,” said study co-author Benjamin Althouse of the Institute of Disease Modeling.

The increase in OraQuick sales was a surprising seven times larger than the sales usually associated with World AIDS Day – the largest and longest-running HIV prevention awareness event.

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The sales volumes mirrored the Internet traffic.

In fact, when the researchers estimated OraQuick sales using the Google data alone, they were able to predict sales figures to within 7 percent for any particular week.

This in itself is a significant finding. Ayers explains its importance:

“Public health leaders are often cautious, choosing to wait for traditional data instead of taking reasonable action in response to novel data, like Internet searches. Our findings underscore the value of big media data for yielding rapid intelligence to make public health actionable and more responsive to the public it serves.”

Going forward and armed with these findings, public health bodies need to be ready to ride the wave of interest as and when it occurs.

The authors believe that the surge in sales following Sheen’s announcement may be due to empathy.

Co-author Jon-Patrick Allem, from the University of Southern California Keck School of Medicine in Los Angeles, interprets the results:

“Our findings build on earlier studies that suggest empathy is easier to motivate others when the empathy is targeted toward an individual versus a group. […] It is easy to imagine that a single individual, like Sheen, disclosing his HIV status may be more compelling and motivating for people than an unnamed mass of individuals or a lecture from public health leaders.”

Because Internet search data are publicly available and accessible in almost real-time, they could provide a useful tool for any group promoting health issues.

By responding to future events similar to Sheen’s interview, an even greater positive influence might be achieved.