Lacking in rigor and having nothing to do with reality!
This is a poorly thought and purposeless book. A modeler will find it to be a mumbo jumbo collection of elementary mathematical techniques not related to each other in a meaningful manner. On the other hand, a practitioner epidemiologist will find that the models presented in the book are merely a selection of toy examples having nothing to do with reality. Given the above, the price of the book is unreasonably high. If the book did not include several mathematical inaccuracies (solution existence conditions, asymptotics etc.), one could possibly use some of its model-examples in an introductory course of mathematical modeling, but unfortunately this is not the case here. Notice that there is a plethora of other books that are appropriate for this task and much-much cheaper.