HSV-1 usually spreads orally and HSV-2 typically spreads genitally. HSV-1 causes 90-95% of oral herpes outbreaks. HSV-1 causes 5-10% of genital herpes outbreaks. HSV-2 causes 90-95% of genital herpes outbreaks and 5-10% of oral herpes outbreaks. Both strains of herpes could spread orally and genitally.
Herpes is spread by coming in direct skin to skin contact with the virus through a mucous membrane. A person with oral HSV-1 could spread the virus to a partner without genital herpes if oral sex is perform. That would be oral positive to genital negative. A partner must come in direct contact with herpes for the virus to spread. If you want to read about the different between HSV-1 and HSV-2 go to the following website. Herpes rarely causes serious health conditions