Gonorrhea is a sexually transmitted infection (STI). It’s caused by infection with the bacterium Neisseria gonorrhoeae. It tends to infect warm, moist areas of the body, including the: 1  urethra (the tube that drains urine from the urinary bladder).2  eyes.3  throat. 4  vagina. 5  anus.onorrhea passes from person to person through unprotected oral, anal, or vaginal sex. People with numerous sexual partners or those who don’t use a condom are at greatest risk of infection. The best protections against infection are abstinence, monogamy (sex with only one partner), and proper condom usage.