Perhaps you should try some spelling variations:
"communicate diseases" » "communicable diseases", "communicated disease", "complicated diseases"
"communicable disease" » "communicable diseases"
"mediated diseases" » "related diseases", "medical diseases", "related disease"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("communicate diseases") OR ((("communicable disease") OR ("mediated diseases")))).
• Removing quotes may allow a broader search: (( communicate diseases ) or ((( communicable disease ) or ( mediated diseases )))).
• Adding a wildcard symbol may retrieve word variants: (("communicate diseases") or ((("communicable disease") or ("mediated diseases"))))*.