Keith: Also, we have to be be honest that sex with an African carries a higher risk. This information is never provided from official sources. I would probably get into trouble if I included that fact in health lessons

You would be failing in your duty if you caused your students to harbour a belief that the way not to contract HIV (or other STI's) is just not to screw Africans. Until all sexually active people not in a totally monogamous relationship learn to use a condom each and every time, the numbers of victims of HIV and various other diseases will continue to rise. That is, essentially, the only lesson that must be taught and learned.