These days HIV is compared to Diabetes in that it's a chronic illness that can be managed through medication and living a healthly lifestyle. Of course this depends upon the individuals circumstances and how early the virus was detected but with combination therapy, HIV sufferers can lead relatively normal lives and live relatively normal lifespans. It is not a legal requirement to inform employers about it. I think it is up to your friend if they tell their family or not but I feel that not telling them may save them from a lot of unneccesary pain and upset.