Postmortem diagnosis of invasive meningococcal disease

Laboratory diagnosis of bacterial meningitis by direct detection, serotyping and Next Generation Sequencing: How 10 years of testing in New York State has evolved to improve laboratory diagnosis and public health

Since 2005, the Wadsworth Center (WC) has provided molecular testing on cerebrospinal fluid (CSF) and whole blood specimens in close collaboration with epidemiologists in New York State and New York City. In this study, we analyzed 10 years of data to demonstrate the significant value of utilizing molecular methods to assess patient specimens for etiologic agents of bacterial meningitis. A comprehensive molecular testing algorithm to detect and serotype/serogroup bacterial agents known to cause bacterial meningitis (Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus agalactiae) has evolved, and retrospective specimen testing has been essential for each improvement. Over a ten-year span from 2010 to 2019 the WC received 831 specimens from 634 patients with suspected bacterial meningitis. Real-time PCR was positive for at least one of the agents in 223 (27%) specimens from 183 patients (29%). Of the 223 positives, 146 (66%) were further characterized by real-time PCR into serogroup/serotype. Additionally, examination of 131 paired specimens of CSF and whole blood from the same patients found better detection in CSF, but whole blood is a useful alternative for diagnosis when CSF is not available. For specimens initially PCR-negative, 16S rDNA Sanger sequencing was requested by the submitter for 146 cases resulting in the identification of bacterial agents in an additional 24 (16%) specimens. In a retrospective study, Next Generation Sequencing (NGS) was evaluated for the detection of pathogens in 53 previously tested PCR-negative CSF specimens and identified bacteria in 14 (26%) specimens. This molecular testing algorithm has provided clinicians a diagnosis when culture is negative with the potential to guide therapy. It has also aided public health in determining when antibiotic prophylaxis was needed, augmented surveillance data to yield a fuller picture of community prevalence, and highlighted gaps in the spectrum of agents that cause bacterial meningitis.

Case Report: Post-mortem Histopathological and Molecular Analyses of the Very First Documented COVID-19-Related Death in Europe

In Europe, the first case of coronavirus disease (COVID-19) and the first COVID-19-related death were reported in France on January 24th and February 15th, 2020, respectively. Officially, the first case of COVID-19 infection in the Republic of Serbia was registered on March 6th. Herein, we presented the first case of retrospective detection of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the post-mortem-obtained vitreous humor (VH), which took place on February 5th, 2020. This is the first death in Europe proven to be caused by COVID-19 by means of post-mortem histopathological and molecular analyses. Based on this finding, it appears that SARS-CoV-2 has been spreading faster and started spreading much earlier than it had been considered and that COVID-19 was probably the cause of the much-reported pneumonia of unknown origin in January and February 2020.

Fatal meningococcal meningitis in a 2-year-old child: A case report

BACKGROUND

In fatal cases of meningococcal septicemia, bacteriological diagnosis may not be straightforward due to postmortem replication and relocation of endogenic microflora. In medicolegal practice, aside from routine autopsy and histopathology, also other diagnostic methods, such as microbiological tests, immunohistochemistry and polymerase chain reaction (PCR), are used to examine body fluids and tissues.

CASE SUMMARY

We present the case of sudden death in a 2-year-old child. The patient died approximately 30 min after hospital admission before any routine diagnostic procedures were undertaken. Presence of whole-body rash and fulminant course of the disease raised suspicion of meningococcal septicemia. An autopsy was performed seven days after death when the body showed the signs of late postmortem decomposition. No etiological factor of septicemia could be identified based on macro- and microscopic findings. However, PCR demonstrated the presence of genetic material of group W Neisseria meningitidis in patient’s cerebrospinal fluid and blood.

CONCLUSION

Microbiological PCR should be conducted postmortem whenever a specific etiological factor could not be identified with conventional methods.

Post-mortem microbiology in sudden death: sampling protocols proposed in different clinical settings

BACKGROUND

Autopsies, including minimally invasive autopsies, are a powerful tool for determination of the cause of death. When a patient dies from an infection, microbiology is crucial to identify the causative organism. Post-mortem microbiology (PMM) aims to detect unexpected infections causing sudden deaths; confirm clinically suspected but unproven infection; evaluate the efficacy of antimicrobial therapy; identify emergent pathogens; and recognize medical errors. Additionally, the analysis of the thanatomicrobiome may help to estimate the post-mortem interval.

AIMS

The aim was to provide advice in the collection of PMM samples and to propose sampling guidelines for microbiologists advising autopsy pathologists facing different sudden death scenarios.

SOURCES

A multidisciplinary team with experts in various fields of microbiology and autopsies on behalf of the ESGFOR (ESCMID - European Society of Clinical Microbiology and Infectious Diseases - study group of forensic and post-mortem microbiology and in collaboration with the European Society of Pathology) developed this narrative review based on a literature search using MedLine and Scopus electronic databases supplemented with their own expertise.

CONTENT

These guidelines address measures to prevent sample contamination in autopsy microbiology; general PMM sampling technique; protocols for PMM sampling in different scenarios and using minimally invasive autopsy; and potential use of the evolving post-mortem microbiome to estimate the post-mortem interval.

IMPLICATIONS

Adequate sampling is paramount to identify the causative organism. Meaningful interpretation of PMM results requires careful evaluation in the context of clinical history, macroscopic and histological findings. Networking and closer collaboration among microbiologists and autopsy pathologists is vital to maximize the yield of PMM.

Community-acquired bacterial meningitis

Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma (nosocomial bacterial meningitis). Despite advances in treatment and vaccinations, community-acquired bacterial meningitis remains one of the most important infectious diseases worldwide. Streptococcus pneumoniae and Neisseria meningitidis are the most common causative bacteria and are associated with high mortality and morbidity; vaccines targeting these organisms, which have designs similar to the successful vaccine that targets Haemophilus influenzae type b meningitis, are now being used in many routine vaccination programmes. Experimental and genetic association studies have increased our knowledge about the pathogenesis of bacterial meningitis. Early antibiotic treatment improves the outcome, but the growing emergence of drug resistance as well as shifts in the distribution of serotypes and groups are fuelling further development of new vaccines and treatment strategies. Corticosteroids were found to be beneficial in high-income countries depending on the bacterial species. Further improvements in the outcome are likely to come from dampening the host inflammatory response and implementing preventive measures, especially the development of new vaccines.