Are there any legal ramifications for being infected by someone with hiv?

Perhaps: We all have an ethical and moral obligation to alert someone to an infectious disease or carrier state before engaging in any high risk behavior. So if you know you have HIV and you don't tell a potential partner, you are certainly ethically and morally obligated to tell them. There are occasionally legal issues that develop.

Yes: If the person failed to disclose, there may be civil or criminal liabilities depending on the state.