Charlie Sheen on Today show
Charlie Sheen's announcement that he is HIV-positive caused huge numbers of people to research into public health on the diseaseAndrew Burton/Getty

The biggest number of HIV-related Google searches in the US occured on 17 November 2015 – the same day that actor Charlie Sheen publicly declared on TV that he is HIV-positive. The actor, most famously known for his role in CBS show Two And A Half Men, appeared on NBC's Today show to put paid to recent rumours and officially announce that he is living with HIV. Research, published in the JAMA Internal Medicine has shown that he may have unknowingly raised awareness of the disease to an all-time high.

On the same day of Sheen's announcement, the number of news stories mentioning the term 'HIV' had increased by 265% from the previous day. In addition, the researchers from San Diego State University in California say that Google searches featuring the term 'HIV' peaked at 2.75m more than the previous average in the US – the most amount of HIV-related Google searches ever recorded in a single day.

Nearly half of those Google searches were considered public health research, as they included the terms 'condoms', 'HIV symptoms' or 'HIV testing'. Researchers believe the interest surrounding HIV was positive for future prevention, as nearly one in eight HIV-positive US citizens are currently unaware of their condition.

"Charlie Sheen's disclosure was a potential earth-shaking event for HIV prevention in the United States," said John Ayres, lead author of the study. "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."

The researchers used Bloomberg Terminal and Google Trends to analyse references to the disease since 2004. Bloomberg Terminal analysed news reports featuring the term 'HIV', while Google Trends focused on the public's active searches.

The results showed that 6,500 more news stories featured 'HIV' compared with the average – with 97% also featuring 'Charlie Sheen'. That means an additional 200 stories were released on 17 November that did not feature Sheen – or the actor's real name, Carlos Irwin Estévez. In terms of public health awareness, condom-related Google searches – for example, 'where to buy condoms' – increased by 75% on 17 November. Searches for 'HIV testing' increased by 214%, and most impressively, searches for 'HIV symptoms' rose by 540%.

"Sheen's disclosure could be an important event to immediately raise public consciousness around HIV, and make public health messages about HIV that much more salient," said Seth Noar, co-author of the study and campaigner for HIV prevention.

Eric Leas, a fellow researcher working on the study added: "Celebrity disclosures are not new to HIV, with Rock Hudson and Magic Johnson serving as noteworthy examples. Yet Sheen's disclosure could be different." Leas added: "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."

Sheen, 2010's highest-paid actor, revealed his condition in an interview with Today show host Matt Lauer. He said: "I'm here to admit that I am in fact HIV-positive." He added: "It's a hard three letters to absorb. It's a turning point in one's life."