STIs, sexually transmitted infections, are the same thing as STDs or sexually transmitted diseases.

STIs are passed during sex and other close body contact. Any person can contract a STI. Although most STI symptoms appear in the genital area, many STIs can affect your entire body. All sexually transmitted infections are treatable and many curable. If left untreated, all STIs can have serious health effects.

(China.org.cn December 16, 2004)