How does Gertrude's line about disease in Scene 5 define all the disease imagery in the play?

In Scene 5 of "Hamlet," Gertrude's reference to disease underscores the pervasive corruption and moral decay within the Danish court. This imagery of disease symbolizes not only the physical ailments affecting characters but also the psychological and ethical malaise that pervades the kingdom. It highlights how the moral rot stemming from betrayal and ambition infects relationships, ultimately leading to tragedy. Thus, Gertrude's line encapsulates the play's broader themes of decay and the consequences of unchecked ambition.