The importance of the postmortem interval for the diagnosis of Waterhouse-Friderichsen syndrome by Neisseria meningitidis in a series of forensic cases

Applications of microbiology to different forensic scenarios - A narrative review

In contrast to other forensic disciplines, forensic microbiology is still too often considered a "side activity" and is not able to make a real and concrete contribution to forensic investigations. Indeed, the various application aspects of this discipline still remain a niche activity and, as a result, microbiological investigations are often omitted or only approximated, in part due to poor report in the literature. However, in certain situations, forensic microbiology can prove to be extremely effective, if not crucial, when all other disciplines fail. Precisely because microorganisms can represent forensic evidence, in this narrative review all the major pathological forensic applications described in the literature have been presented. The goal of our review is to highlight the versatility and transversality of microbiology in forensic science and to provide a comprehensive source of literature to refer to when needed.

Utility and diagnostic value of postmortem microbiology associated with histology for forensic purposes

Nowadays, the diagnostic value of postmortem microbiological investigations is still a debated topic, but postmortem microbiology (PMM) remains a discipline with great forensic potential. To evaluate the usefulness and diagnostic-forensic value of postmortem microbiological cultures, it has been conducted a study on cadaveric material sampled during autopsy aiming to identify the correct cause of death. The study analyzed 45 cadavers subjected to judicial autopsy, divided into two groups based on the presence or absence of external or internal macroscopic autopsy signs suggesting infectious pathology. In the same cases, both the microbiological and conventional histological investigations have been simultaneously carried out. From the investigations, mono-bacterial, mono-fungal, mixed and negative cultures were observed. In mono-species microbiological growth, the histological epicrisis confirmed an infectious cause of death due to the presence of signs of acute infection with an aggressive infectious agent. In cases where growth was mixed, it was possible to distinguish between simple postmortal contamination and perimortem colonization. Finally, in some cases where the microbiology was negative, this has been essential in highlighting signs of a vital reaction to viral or parasitic infection. The joint and integrated evaluation of the laboratory results made it possible to correctly understand even those peculiar situations in which the PMM results alone would not have been significant. These methods, when combined, constitute an optimal forensic approach for the identification of the real cause of death and thus reduce the number of unsolved cases.

Fatal Waterhouse-Friderichsen syndrome in an adult due to serogroup Y Neisseria meningitidis

Waterhouse-Friderichsen syndrome (WFS), defined as severe adrenal insufficiency due to bilateral adrenal gland haemorrhagic necrosis, occurred in a 59-year-old woman. An underlying serogroup Y Neisseria meningitidis (NM) infection was diagnosed, with a rapid progression to purpura fulminans, disseminated intravascular coagulation and WFS. Intensive treatment including fluid resuscitation, broad-spectrum antibiotic therapy, ventilatory support, platelet and factor replacement were administered. The meningococcaemia in the presence of WFS had a fulminant progression, leading to a fatal outcome within 24 hours of symptom onset. This case details the diagnosis and management challenges of the WFS, a rare complication of NM septicaemia, and describes the identification of a NM serogroup that is rare in Portugal in middle-aged patients.