This is a very difficult question, and one with no clear consensus yet. However, it does appear that there may be differences. For example, Class I pneumococcal pneumonia, according to the Fine classification (8), can be safely treated as outpatients and are likely to have a low pathogen burden. In this situation, it is probable that stasis exposure would have a high probability of a good clinical outcome. However, in Class V of the Fine classification, it is probable that at least a 1-log kill or more is required to overcome the bacteremia.