Although in EMT class they really don't cover as much as they should, when you get hired your employers are supposed to get you "trained" for all of the above. Most employers also lack the adequate level of in house training regarding bloodborne pathogens and their own policies on how to handle/prevent exposures.
TB is scary and fairly rare unless you have large prison polulations you serve. Its transmitted in the vapor droplets. Put a mask on the patient if they have a cough and/or put a mask on yourself. Even if its not TB your protected agianst SARS, avian flu or whatever else could be "infecting" them. Hell most of the time its a simple flu or virus anyway. Use that noisy exhaust fan in the back of your bus to keep some air moving.
As far as preventing disease transmission, wear gloves and wash your hands after every run. According to the CDC its the greatest one thing you can do to prevent transmission of any disease, germs, etc.