Probably because it's only a comorbidity. We seem to want easy answers to all these question but the reality is that humans are complex organisms. Having one is

Probably because it's only a comorbidity. We seem to want easy answers to all these question but the reality is that humans are complex organisms. Having one issue (i.e. an infection) without another (i.e. some specific genetic corruption) will not result in the individual developing a disease however the combination of 2 or more factors results in the development of a disease.