Perhaps you should try some spelling variations:
decrease spread » disease spread (Expand search), decreases spreading (Expand search), decreased steady (Expand search)
spread patterns » spread pattern (Expand search)
il decreased » is decreased (Expand search), in decreased (Expand search), oil decreases (Expand search)
decreased by » decreased in (Expand search), increased by (Expand search), decreased il (Expand search)
decrease and » decreases and (Expand search), decrease in (Expand search), decrease of (Expand search)
and decrease » and decreases (Expand search), and decreased (Expand search), and increase (Expand search)
decrease il » decreased il (Expand search), decrease in (Expand search), decrease hiv (Expand search)
by decrease » by decreased (Expand search), may decrease (Expand search), any decrease (Expand search)

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: (( decrease il decreased by decrease ) OR ( decrease AND decrease spread patterns ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease il decreased by decrease ) OR ( decrease and decrease spread patterns ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease il decreased by decrease ) OR ( decrease and decrease spread patterns ))*.