My husband contacted by an ex re an STI

My husband received an email from a former girlfriend asking him to contact her about a non- serious health concern. She said don’t worry it’s not HIV. We’ve been together for 10 years. How far back do people contact their previous partners? I feel like it’s weird that she’s contacting him unless something happened more recently. I know the girl has had mental health issues in the past and he doesn’t want to contact her because she was really clingy and not balanced but do you think I should insist that he does to hear what she has to say? Maybe I should contact her myself? According to him, he last saw her two years ago. Advice please.