HIV + patient

Had a HIV + patient (aged 35) come for a checkup along with his wife n daughter… he had mostly got his HIV through his exploits with a prostitute… a look at his very innocent looking wife and kid made me ponder their future… I hoped the kid was conceived before his exploits so that she having the disease was unlikely… but then what about his wife… when this man couldn’t hold on to his sexual urge at ‘that’ point of time, it was unlikely that he may control it on his wife in future.. she was bound to contract it in future… I couldn’t do anything but pity on his family and their future… the kid was amused on seeing her father getting checked.. she was smiling and playing around… just the thought of maybe the innocent looking kid having the disease brought tears in my eyes… anger swelled in me for the patient… but now that the damage was already done… I felt helpless… if he could have avoided that one moment of urge, things could have been different today…
What exactly is the thing that compels a guy to go to a prostitute for his sexual gratification…??? I have tried to find it out by indirectly asking people I know who have been involved in this thing… but am still unable to get a satisfactory answer… one said… it was out of frustration… one went just for the sake of curiosity… one for fun… one went to see if he would be able to satisfy his wife since he was soon to get married… he said it would rather face an embarrassment before a prostitute than his wife… one went because the other went… so there were multiple factors involved… but then at what cost?? Haven’t they heard of something know as HIV or HBsAg??? These are viruses having no treatment at present… maybe someone should put photos of people suffering from HIV… maybe that would deter many from opting for such step… but then I have known even a doctor I knew going for the same… so… what else???