Yes, and be careful with all kinds of infectious veneral diseases!....

All kinds of venereal disease are infectious, as far as I know. That's the nature of the beast. So 'infectious' is superfluous in your sentence, and should therefore be omitted. As for 'veneral disease', what's that exactly, or is it a typo?
How to be careful? Avoid kissing, and use a rubber. BTW, it's not just sexual diseases and AIDS that one must be wary of - there's also hepatitis. It's very nasty too, and can be spread by unprotected sex and body fluids.