Pathogens can spread in a variety of different ways. For example, direct skin-to-skin contact during sex can lead to sexually transmitted infections (STIs).
Coughing or sneezing can cause pathogens to spread through tiny droplets in the air. These droplets can contain microorganisms, which other people breathe in.
Microorganisms can also travel straight into the gut when a person consumes contaminated food or water.
Bites from infected insects can also spread disease. For example, ticks with a bacterial infection can cause Lyme disease if they bite someone, and mosquitoes with a viral infection can cause Zika virus disease.