We appreciate the comments by Drs. Meurs et al on our study detailing the epidemiology and outcomes of culture negative severe sepsis. We agree with the authors that systemic inflammatory response syndrome (SIRS) symptoms can be elicited by not only infections (identified or unidentified), but also other inflammatory conditions. It is, however, important to understand that these patients who qualify for the definition of severe sepsis but are in fact culture negative (ie, have culture negative severe sepsis) are a distinct cohort of patients with worse outcomes and therefore need to be looked at more carefully during evaluations. Our study provides an important groundwork for designing future studies to investigate and improve outcomes for this distinct population. It will also be important to see how this cohort changes with the adoption of the new definition of sepsis. Rather than defining a new term, the aim of our study was to describe and direct attention toward this vulnerable population. We would, therefore, propose to avoid using the new terminology of SIRS-unknown origin as suggested by the authors, especially because SIRS criteria are going out of favor for more updated definitions of sepsis.