According to a British study published in the May issue of Lancet, a bacterial infection or bacterial toxins may be responsible for the onset of sudden death syndrome (SHS) in an infant.

As the researchers noted, the results of a microbiological autopsy study obtained in cases of SHS are often positive, but the clinical significance of these results remains unclear.

The study analyzed 507 cases of SHS for the period from 1996 to 2005, in which an autopsy was performed. Based on gross and histological data, 72 cases were considered to be inherently non-infectious, such as trauma or congenital disease, and in 56 cases, foci of acute neutrophilic inflammation were found in the tissues. The remaining 379 deaths were considered to have an unexplained cause.

Of the 2,079 bacteriological samples obtained, 73% were positive and 57% of the strains isolated from microorganisms were considered as potentially pathogenic.

According to the researchers, pathogens can be detected in a culture study in about a quarter of deaths with a known non-infectious cause, confirming that a simple identification of pathogens does not necessarily indicate the cause of death. However, the isolation of Staphylococcus aureus and Escherichia coli (mainly from lung and spleen tissue) was noted more often in the group of children, whose deaths could not be explained by other reasons, compared to children whose death found another reasonable explanation.

Both organisms can cause sudden death syndrome. But, on the other hand, the isolation of these pathogens can be considered an epiphenomenon (i.e. it is a complication or a secondary phenomenon), indicating another cause main cause of death, such as overheating the child or damage to arousal processes due to mutations in genes.

Researchers do not rule out that in the event of sudden death syndrome, the cause of a rapid deterioration in the child's condition may be the effect of bacterial toxins on the cardiovascular, respiratory or nervous system. Proteomics (science, the main subject of which is proteins and their interactions in living organisms, including the human body) proposes to use new technologies for the recognition of bacterial proteins in human bodily fluids, and this achievement is the next step in studying the causes of sudden infant death syndrome.