Male circumcision is a surgical procedure that involves the removal of all or part of the foreskin from the head of the penis.
It has been known for many years that men who have a foreskin (i.e.they have not been circumcised) are at greater risk of acquiring HIV from women via vaginal (and anal) intercourse. Recent studies in Africa have shown that circumcising men reduces their risk of contracting HIV from women by about 60%. As a result, circumcision is now being advocated in those countries with a high prevalence of HIV, and predominantly heterosexually spread.
However, circumcision is not currently being promoted at a population level, in countries such as Australia, because HIV is predominantly spread amongst men who have sex with men.
However, circumcision is something an HIV positive woman and her HIV negative partner may wish to consider, in which case it is recommended that you discuss this with your doctor.
Links:
[1] http://www.napwa.org.au/resource/treat-yourself-right/sex/menstruation-and-sex
[2] http://www.napwa.org.au/resource/treat-yourself-right/sex
[3] http://www.napwa.org.au/resource/treat-yourself-right/sex/sexual-practices-and-sex-toys