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Pneumococcal infections as a sudden death cause: forensic microbiological diagnosis

Abstract number: P1052

Abad Moralejo R., Fernandez-Rodriguez M.A.

Objectives: Pneumococcal infection (PI) is a main cause of community-acquired pneumonia (CAP) and meningitis in adults, sometimes leading to a fatal outcome. The incidence of PI as responsible of sudden unexpected death (SUD) has not been established to date. Since SUD usually occurs outside of the hospital or soon after arrival in the emergency department, in most occasions a microbiological analysis is not performed at the hospital and a medico-legal autopsy is performed. The aim of this study was to determine the incidence of PI as a cause of SUD and to assess the utility of different techniques to detect this pathogen in forensic postmortem samples.

Methods: Specimens were received from the different Forensic Pathology Services all along Spain. We designed a flexible protocol including: (i) detection of capsular pneumococcal antigen by latex agglutination and immunocromatography, (ii) bacteriological culture of forensic samples, and (iii) detection of pneumococcal DNA by PCR (ply, lytA and psa genes). Antigenic detection was always considered a presumptive result. A positive result for a sample was defined when a pneumococcus had been isolated by culture and/or when a positive real time PCR result was obtained from a sterile fluid or tissue.

Results: We analyzed 377 SUD (255 in adults and 122 in infants) (age range 19 days-90 years) and 1971 samples. In 46 SUD cases a pneumococcus was detected, 36 in adults (age range 19–74) and 7 in infants (4–16months) (16 females and 30 males). The cause of death was directly attributed to pneumococcus in 44 of them according to histopathology. Concomitant diseases were present at least in 32 of them. One infant SUD had co-infection with the H1N1 virus. Other pathogens were detected in 8 cases. In 38.3% of the positive cases the diagnosis of PI was made by culture. In a 25.5% of the cases the diagnosis was established by both culture and PCR. In a 36.2% only the PCR assay permitted the detection of pneumococcus and, in 35.3% out of them, the only specimen where a positive PCR result was obtained was a paraffin-embedded tissue.

Conclusion: Pneumococcus is a pathogen involved in sudden death, mainly due to meningitis (52.2%), CAP (28.3%) and Waterhouse-Friederichen syndrome (15.2%). Attention should be paid when chronic underlying diseases are present. A combined protocol including culture and molecular techniques such a real time PCR is required to detect this pathogen in forensic samples.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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