Postmortem microbiological sampling: a prospective ESGFOR-supported study on relevance, timing, and site selection.

Area of Science:

• Forensic pathology
• Medical microbiology
• Infectious disease diagnostics

Background:

• Postmortem microbiological testing is crucial for confirming infectious causes of death.
• Lack of standardized guidelines and consensus complicates interpretation of results.
• Variability in sampling sites and postmortem intervals (PMI) affects accuracy.

Purpose of the Study:

• To evaluate the diagnostic relevance of postmortem microbiology.
• To assess site- and time-related factors influencing microbiological findings.
• To establish a standardized protocol for postmortem sample collection.

Main Methods:

• Prospective single-center study involving 200 clinical and forensic autopsies (2013-2016).
• Collection of 1321 samples from various anatomical sites.
• Comparison of microbiological results against histopathological classification as the gold standard.

Main Results:

• Infectious causes of death were identified in approximately one-fifth of cases, primarily pneumonia.
• Microorganism (MO) group, number of positive sites, specific sampling sites, and unique pathogen presence significantly correlated with infectious deaths.
• Polymicrobial overgrowth was mainly associated with non-pathogenic MOs, suggesting contamination.

Conclusions:

• A standardized protocol recommending specific sampling sites (e.g., peripheral blood, heart blood, left lung, spleen) is proposed.
• Microbiological findings are significantly related to infectious causes of death.
• Further investigation is needed to clarify the clinical relevance of the postmortem interval on microbiological results.