I’m watching TNG s4e26/s5e1 “Redemption”. There’s a scene where Worf’s honor is restored, by grabbing and bloodying Gowron’s d’k tahg. This got me thinking, Klingons absolutely adore blood rituals. Presumably, 24th century medicine makes contracting an STD a trivial issue. However, 21st century equivalent medicine would be far more limited.
They are extremely violent, and sustain countless injuries throughout their lives. They likely evolved to be able to resist infections and heal quickly.