When will the storyliners/scriptwriters realise that having a character revert into denial just to build up tension is unrealistic and predictable? Zac has up until now, been protrayed as a lucid, moral man with his head screwed on and a slight Beano boy element. He is also a fitness coach and would surely know that evidently 'healthy' people can be HIV positive. He is not that naive. Surely he would confide in Sharon, his sister, who has given him unconditional love since they met. Yet, no, we go in to denial mode and lies to build up 'drama'. Whitney NEEDS to know, as she and the baby are at risk of the virus. Moral Zac would not lie to them. He would be bricking it, for sure, but he would make sure Whitney got checked out.
This is the writers being economical with the storylines and stretching them out to make them last. It is frustrating and also boring. Sharon's best friend's brother died of AIDS. She is not going to be perplexed at Zac's situation.