#Wikidata uses the GND classification and twice it has been proposed to get rid of its use. So far the issue has been unresolved.
To understand the GND classification, you have to appreciate its origin. This classification has been created and is maintained by the Deutsche National Bibliothek. The consequence is that we cannot modify this classification to suit our needs and still call it the "GND classification.
When a library creates a classification for its own purposes, it is perfectly all right to classify "typhus" as a "Term". From a library point of view it is and publications may refer to it. When you look at it from the use of something like Wikipedia, it is likely to be categorised as something like a bacterial disease.
In this context, we can assume that all bacterial diseases are caused by a bacterium. This bacteria has a name. The disease will be known in one or more medical classifications. It being a disease, it will have all kinds of other attributes and none of them are easily associated with the classification as a "term".
The one thing we should retain of the GND classification in Wikidata is the identifier of a Wikidata item as used by the GND classification. This will allow us to compare information with the Deutsche National Bibliothek.
Obviously, once it has been decided to ditch the GND classification in Wikidata, we need to carefully migrate to a classification that is more appropriate.