With cases of STIs on the rise, basic methods of protection are more important than ever.(Credit: Purple Anvil/Shutterstock)

When it comes to sexually transmitted infections (STIs), we all know the classics: Syphilis, chlamydia, gonorrhea and the like. But these health-class terrors are not the only microbes that can get passed on through sexual contact.

There are more than 30 known STIs, and four in particular are becoming more common at a worrying rate. Some are developing antibiotic re