Quick Answer
Mononucleosis (the kissing disease) is caused by Epstein-Barr virus (EBV). It spreads through saliva, including kissing, but is not classified as an STI because it is not sexually transmitted.
- EBV infects ~90% of adults by age 40.
- Spread through saliva, not sexual fluids.
- Not classified as an STI by CDC or WHO.
- Symptoms: severe fatigue, sore throat, swollen lymph nodes.
Context Most Pages Skip
Mono is a common infection often confused with STIs.
⚕️ This page is educational and does not replace advice from a licensed clinician. If you may have been exposed to an STI, get tested — most infections are manageable, and many are fully curable.
Sources & Further Reading
- CDC — Sexually Transmitted Infections
- CDC STI Treatment Guidelines
- WHO — Sexually transmitted infections fact sheet
- MedlinePlus — Sexually Transmitted Diseases
Figures reflect CDC surveillance and WHO estimates; they are population statistics, not personal risk predictions.