Perhaps you should try some spelling variations:
"communicated diseases" » "communicable diseases", "communicable disease", "communicate disabled", "communicable diseasess", "communicate states"
"communicated disease" » "communicable disease", "communicable diseases", "communicate state"
"complicated diseases" » "complicated cases", "complicated case"
"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: (((("communicated diseases") OR ("communicated disease"))) OR ((((("complicated diseases") OR ("complex diseases"))) OR ((("mediated diseases") OR ("related disease")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"communicated diseases\") or (\"communicated disease\"))) or (((((\"complicated diseases\") or (\"complex diseases\"))) or (((\"mediated diseases\") OR (\"related disease\"))))))".
• Removing quotes may allow a broader search: (((( communicated diseases ) or ( communicated disease ))) or ((((( complicated diseases ) or ( complex diseases ))) or ((( mediated diseases ) OR ( related disease )))))).
• Adding a wildcard symbol may retrieve word variants: (((("communicated diseases") or ("communicated disease"))) or ((((("complicated diseases") or ("complex diseases"))) or ((("mediated diseases") OR ("related disease"))))))*.