HIV/Child Support laws in Thailand

[salerns]

I have a very complicated situation and need to find information on the International laws that apply.

In summary: I have an HIV positive brother that has disappeared in Asia. Recently, I received information that he was in the Philippines and is now in Thailand. At one time, he told me that the HIV medication he is taking has reduced the levels in his blood so that he tests negative on an HIV test. I have information that he may have married and may also have a young girl in the Philippines that is pregnant. I don't believe that these women are aware of his HIV.

Legally: I have read on the internet that a person with HIV should not have a Visa to be in Thailand or the Philippines. I don't have any medical documents to prove that he is HIV positive. I have a prescription bottle with his name for one of his HIV medications but I would assume this is not information to revoke his Visa or his US passport.

Legal advice: What legal rights does the girl in the Philippines have to establish paternity and receive support from my brother? I know there are confidential medical records in the US that confirm he is HIV positive-is there anyway I can obtain the medical records? What documents would be needed to revoke his visa in Thailand/the Philippines or to revoke his US passport?