How does a sexually transmitted infection spread?
water and humidity
enviromental contact
linear contact
sexual contact
A sexually transmitted infection (STI) is an infection that spreads through sexual contact. STIs are caused by pathogens , a living thing or virus that causes infection. The pathogens enter the body through the reproductive organs. Many STIs also spread through body fluids, such as blood. For example, a shared tattoo needle is one way an STI could spread. Some STIs can also spread from a mother to her baby during childbirth.