why hiv transmission doesnt always occur?and how?

i am writing this to understand better how transmission works
i was reading the stats and it says a man can have sex with an infected woman for 1000 and not get aids
not just female to male other forms of sex have relativly low stats too
why is that?
does he get exposed to the virus and his immune system is somehow able to fight it off?
is it that he doesnt get exposed at all cause the body fluid doesnt have much viral density on it?
are big amounts of virus needed in order to get hiv or a singe cell of hiv is enough?

i read somewhere a single drop of blood has enough virus concentration to make you sick...but thats not the same for other fluids?like the vaginal fluid?

[chris2ask]

looks like people dont find this thread very interesting
it could help people to understand the risks though and how to interpret the stats

[Vance2335]

This is a risk assestment forum, not an education of HIV forum. Also it takes just one time and we want to stress that. 1 time.

[chris2ask]

i suppose you are right but perhaps people(including myself) could be less paranoid about hiv if they actually knew how it works

[chris2ask]

bump

[zamzam4]

Chris, what more do you want to know than what you have already been told.  HIV is transmittted through unprotected penetrative sex, IV drug abuse, mother to child.  It is not transmitted upon exposure to the environment.

Unless you plan on working in HIV research why do you need to know more?  I feel that by providing you study after study you will still go on to question and doubt and that your irrational fear of HIV will not get better by spending hour after hour pouring over scientific papers that you may or may not understand.

[chris2ask]

actually you are quite wrong about this
this isnt just about me and my case i am sure many other people dont really know how to interprete the statistics and this knowledge could definitely be useful...

my irrational fear you say?but how do we really know its irrational unless we actually check the scientific facts and not just people opinions...

now about me:i am doing quite better lately and reading dr hooks response on some other guy with the same problem offered some reassurance
its not completely out of my system though...i feel like being educated about hiv a little more might be needed

[RainLover71]

Read the posts in the expert doctors forum if you want to educate yourself about Hiv and How it's transmitted,window periods for different tests and symptoms,etc.They are experts with 3 decades of experience between them.