A suggestion is maybe he should meet "people with HIV" to show that even if he did have HIV its not the end of the world. People with "HIV" are living 30+ years after the diagnosis, medicines are getting better, people's awareness is getting better, and people with "HIV" are educating people and how to prevent "HIV" I realize that after (12) weeks of HIV negative test that I do not have HIV. I have been tested (5) times in (12) weeks. Talk about excessive worrying. I am more concerned with testing now for "HEP B" then HIV. However I need to handle this one step at a time or I will be put into a mental institute myself.
Alot of times people do get things from having unprotected sex with prositutes or non prositutes. Your brother may have gotten something but one thing is sure it is not HIV.
your brother could have contracted Hepatits A which goes away on its own. People know there bodies and are aware that there bodies are changing and many people become alarmed and assume the worst. Yes, it is possible that your brother may have gotten something from this girl. However it is not "HIV" did he check for other std's? In most likely hood the immune system can heal own its own. I believe your brother may have gotten something like LGV Lymphogranuloma Venereum which with anti-biotics goes away from itself. Sometimes assuming the worst is something many people do because of the guilt of sleeping with a prositute. But the thing is alot of prositutes are sometimes cleaner than a girl who is promiscuous. They are paid sex workers, most of them do take std testing on a daily basis and make sure the man uses "latex condom"
Its ironic if you think prositutes carry condoms with them. Most girls who are promiscuous do put condoms in there purses.
I have heard lots of stories about anxiety over stds, but this is ovbiously well beyond that. This could be hypochondria or OCD. I assume he's getting treated by a psychiatrist?
Its ironic that most men freak about HIV from a prostitute when most prostitutes don't have HIV.
I don't know what to tell you that will make him believe it. He's had specialists tell him the tests are accurate, and he has some clear mental health issues going here.
If he's not in treatment, then you should probably take some steps to see if you can make that happen. You might have to contact an attorney to see what the steps are for that if you think he needs to be forced into treatment.
Good luck, sincerely.
AJ