An infection caused by herpes simplex virus 2 (HSV-2) and usually associated with lesions in the genital or anal area. HSV-2 is very contagious and is transmitted by sexual contact with someone who is infected (even if lesions are not visible). Treatment cannot eradicate HSV-2 from the body, but antiviral therapy can shorten and prevent outbreaks and reduce the risk of transmission. People with weakened immune systems, such as people with HIV, are more likely to have lesions that spread to other parts of the body than people with healthy immune systems.