Grat infographic on safe use of common water points. (Source)
Global Handwashing Partnership
Infographic from the Global Handwashing Partnership (available here in PDF)
World Health Organisation
Mythbusting messages from the World Health Organisation, you can find more examples by following this link.
Illustrations by Mona Chalabi
Creative public health messages. More pictures available here.
Center for Disease Control and Prevention
Comics for good
More comics available here.