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

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 ("communicated disease"))) OR ((("mediated diseases") OR ("related disease")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"communicate diseases\") OR (\"communicated disease\"))) or (((\"mediated diseases\") or (\"related disease\"))))".
• Removing quotes may allow a broader search: (((( communicate diseases ) OR ( communicated disease ))) or ((( mediated diseases ) or ( related disease )))).
• Adding a wildcard symbol may retrieve word variants: (((("communicate diseases") OR ("communicated disease"))) or ((("mediated diseases") or ("related disease"))))*.