Sexually Transmitted Infections (STI), or Sexually Transmitted Diseases (STD) are generally acquired by sexual contact. The organisms that cause sexually transmitted diseases may pass from person to person in blood, semen, vaginal and other bodily fluids/secretions.
Sometimes these infections can be transmitted non-sexually, such as:
- From mother to infant during pregnancy or childbirth
- Through blood transfusions
- Through needles
It is possible to contract sexually transmitted diseases from people who seem perfectly healthy, and who may not even be aware of the infection.