Immune biomarkers as an adjunct diagnostic modality of infection in cases of sudden and unexpected death in infancy (SUDI) at Tygerberg Medico-legal Mortuary, Cape Town, South Africa

Child mortality is a major health concern worldwide with over 4.2 million infants dying before reaching the age of one year in 2016 alone. Several international intervention initiatives have resulted in a decrease in the number of infant deaths; however, the incidence of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) remain unacceptably high. SIDS still accounts for approximately 50–80% of SUDI cases, followed by infection.The aim of this study was to investigate a selection of immune biomarkers that are associated with an immune response in an effort to support the diagnosis of an infectious cause (“Infection”) e.g. bronchopneumonia, interstitial pneumonitis, etc., instead of SIDS in SUDI cases. C-reactive protein and 18 different cytokines were retrospectively quantified in serum collected during post-mortem investigations of SUDI cases admitted to the Tygerberg Medico-legal Mortuary in the Western Cape Province of South Africa between 2015 and 2017. Statistical comparison was done between infants with a final cause of death (COD) of Infection and SIDS to investigate any correlations between the immune markers and sociodemographic information of the groups. A p-value of