Post-mortem diagnosis, of cytomegalovirus and varicella zoster virus co-infection by combined histology and tissue molecular biology, in a sudden unexplained infant death.

BACKGROUND: An autopsy case of a two-month-old male infant who suddenly and unexpectedly died during his sleep, eight days after the onset of benign varicella. OBJECTIVES: To describe post-mortem combined histological and tissue molecular biological techniques for the diagnosis of cytomegalovirus and varicella zoster virus co-infection as a cause of death. STUDY DESIGN: Real-time quantitative PCR and RT-PCR assays for Herpesviruses, respiratory viruses, Adenovirus, Enterovirus and Parvovirus B19 were performed on multi-organ frozen samples and paraffin-embedded tissues in combination with histology. RESULTS: Cytomegalovirus and varicella zoster virus were detected by molecular biology with highest viral loads detected in the lungs (4.6×10(7) and 1.9×10(5) genome copies per million of cells, respectively). Pulmonary extensive necrotizing inflammation and immunohistochemistry correlated to virological data. Virological molecular biology was negative on paraffin-embedded tissues. CONCLUSIONS: This case shows that thorough quantitative virological investigations on frozen tissues must be performed in combination with histology and immunohistochemistry for the determination of the cause of a sudden unexplained infant death.

[Investigation of the sudden infant death syndrome: a multidisciplinary approach is required]. / Exploration d'une mort inattendue du nourrisson : nécessité d'une approche multidisciplinaire.

The concept of sudden infant death syndrome (SIDS) is defined as the sudden, unexpected death of an infant less than a year old which remains unexplained after in-depth investigations comprising a complete autopsy, biological analyses, and a clinical examination of the circumstances surrounding the death. This definition underlines the importance of finding the cause of this disease in order to improve preventative measures to reduce the number of deaths due to sudden infant death syndrome. Among the causes of SIDS, pediatric infectious diseases may be neglected and must be systematically sought after. We report upon a SIDS death case of a four and a half month-old that occurred during his sleep. Following the absence of an evident cause of death a scientific autopsy was performed. The histological examination of pulmonary tissue revealed broncolitic lesions associated with numerous micro-abscesses. The post mortem microbiological analyses revealed evidence of an infection by the respiratory syncytial virus complicated by a bacterial infection due to Haemophilus influenzae. The case underlines the necessity of a multidisciplinary approach to researching SIDS, involving both clinicians and biologists, in order to determine the causes of these deaths.