Perhaps you should try some spelling variations:
"decrease pathogen load" » "decrease pathogens load" (Expand Search), "decrease pathogen lead" (Expand Search)
"decreased pathogen load" » "decreased pathogens load" (Expand Search), "decreased pathogen lead" (Expand Search)
"increase pathogenic load" » "increase pathogensic load" (Expand Search), "increase pathogenic lead" (Expand Search), "increase pathogens load" (Expand Search), "increase pathogenesis load" (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("decrease pathogen load") OR ("decreased pathogen load"))) OR ("increase pathogenic load"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"decrease pathogen load\") OR (\"decreased pathogen load\"))) OR (\"increase pathogenic load\"))".
• Removing quotes may allow a broader search: (((( decrease pathogen load ) OR ( decreased pathogen load ))) OR ( increase pathogenic load )).
• Adding a wildcard symbol may retrieve word variants: (((("decrease pathogen load") OR ("decreased pathogen load"))) OR ("increase pathogenic load"))*.