Perhaps you should try some spelling variations:
communicated diseases » communicated disease, communicable diseases, communicable disease
complicated diseases » 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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"communicated diseases\\") or (((\\"((complicated diseases) OR (complicated cases))\\") or (\\"mediated diseases\\"))))\"".
• Removing quotes may allow a broader search: (( communicated diseases ) or ((( ((complicated diseases) OR (complicated cases)) ) or ( mediated diseases )))).