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