CDC Yellow Book
- Yangtze River, cruising
- Yap Islands
- YEL-AND (see yellow fever vaccine-associated neurologic disease)
- YEL-AVD (yellow fever vaccine-associated viscerotropic disease)
- yellow fever vaccine-associated neurologic disease (YEL-AND)
- yellow fever vaccine-associated viscerotropic disease (YEL-AVD)
- Yemen
- yersiniosis