Perhaps you should try some spelling variations:
"infections diseases" » "infection diseases", "infectious disease", "infection disease", "infectious diseases", "infection diseasess"
"infection diseasess" » "infection diseases", "infection disease", "infective diseases"
"infections disease" » "infectious disease", "infection disease", "infection 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: (((((("infections diseases") OR ("infection diseasess"))) OR ("infections disease"))) OR ("infectious diseases")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"infections diseases\") OR (\"infection diseasess\"))) or (\"infections disease\"))) or (\"infectious diseases\"))".
• Removing quotes may allow a broader search: (((((( infections diseases ) OR ( infection diseasess ))) or ( infections disease ))) or ( infectious diseases )).
• Adding a wildcard symbol may retrieve word variants: (((((("infections diseases") OR ("infection diseasess"))) or ("infections disease"))) or ("infectious diseases"))*.