Hookup websites and apps may be behind the growing number of newly HIV infected men in the US, a new study has said, cautioning people about the risks of sexual encounters arranged online. More than 60 per cent of men in the US state of Rhode Island who had sex with men and were diagnosed with HIV in 2013 reported meeting their sexual partners online in the preceding year, said the study that interviewed 70 of the state's 74 newly diagnosed people. In 2013, 74 Rhode Island residents were newly diagnosed with HIV. Three in five were gay, bisexual, or others. And of the 43 people, 22 told researchers they believed a man they met online gave them the virus. "This is a statewide study that included nearly all individuals newly diagnosed with HIV across an entire state," said Amy Nunn, associate professor of Public Health and Medicine at Brown University and director of the Rhode Island Public Health Institute.