Infection is a type of Incident. Scene is a type of Incident. Scene is related to Background. 
Feeling is related to Anxiety. Anxiety is related to Nervous. Nervous is a synonym of Anxious. 
Infection --IsA--> Incident <--IsA-- Scene <--RelatedTo--> Background 
Feeling <--RelatedTo--> Anxiety <--RelatedTo--> Nervous <--Synonym--> Anxious 