I & my partner of 6 years are HIV positive. I have just learned he has been sexually active during our relationship with other women without disclosing his status. These women could now be HIV positive, along with all of their partners. Should the information be disclosed by me to protect and inform them?

This is something that you need to discuss with your partner. If he has been sexually active with other women and if he is not disclosing his status to them, then you need to be concerned about what other things he is not disclosing to you. For example, you being HIV+ does not protect you from becoming "superinfected." This means being infected by another strain of the virus, especially one that is resistant to some antiretroviral drugs. He is not using protection with other partners, and he may expose you to other strains if the two of you don't use adequate protection.

As far as informing others is concerned, this is not your job, it is his. In some states (like New York), a physician or public health officer can inform sexual contacts. You should encourage your partner to inform the partners himself, or to discuss this with his physician to see if he or a public health officer might perform this service.