Infection and Sudden Unexpected Death in Infancy 

29 May 2008

Infection and Sudden Unexpected Death in Infancy: a statement from the Foundation for the Study of Infant Deaths

The Foundation for the Study of Infant Deaths (FSID) welcomes the findings of the research by Weber MA et al, Infection and sudden unexpected death in infancy: a systematic retrospective case review published in The Lancet on 31 May 2008.

The research, funded by FSID, reviewed autopsies undertaken between 1996 and 2005 at Great Ormond Street Hospital for Children of 507 infants, aged one week to one year, who died suddenly and unexpectedly. The researchers categorised the cases of Sudden Unexpected Death in Infancy (SUDI) as either unexplained (379 infants); explained with evidence of bacterial infection such as pneumonia, meningitis or another infection deemed to be sufficient to cause death (56 infants), or explained by non-infective causes such as congenital heart disease or head injury or other accidents (72 infants).

The research found that more than 70% of the post-mortem bacteriological samples that were analysed showed the presence of microbial organisms, but there were no differences in the overall rates between the three categories of deaths, indicating that the mere detection of organisms at post-mortem is not a cause of death. However, the prevalence of group 2 pathogens (organisms that can cause bacteraemia/ septicaemia in life without there being an identifiable focus of infection such as Staphylococcus aureus and Escherichia coli) was significantly greater in both the unexplained and bacterial infection group than in the non-infective group, suggesting that infection or colonisation with a group 2 pathogen could be linked to a subset of otherwise unexplained SUDI.

FSID therefore supports the study’s recommendation of the need for more investigation into the mechanism involved in the unexplained SUDI cases where group 2 pathogens were found, and especially how the presence of microbes or microbial products could in some way lead to these deaths.

Professor George Haycock, FSID’s scientific adviser, says: “Bacteria can cause death by more than one mechanism. The first and most obvious is by causing invasive infection, where the bacteria actually enter the body and cause, for example, septicaemia, meningitis or pneumonia. There is also evidence that they can cause death without invading the body, for example by colonising the pharynx (the upper airway) from where toxins produced by the bacteria may enter the bloodstream.

“Several studies (1), some of them funded by FSID, suggest that small genetic variations in the chemicals (cytokines) that control the inflammatory response to infections and to exposure to toxins may cause some infants to have an exaggerated, possibly overwhelming, inflammatory reaction whereas others might experience little or no disturbance. More research funded by FSID is currently being conducted along these lines.”

The study also confirms the need for careful paediatric pathology to be a part of the investigation of all infant deaths, as called for in our Responding When a Baby Dies campaign (2).

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Notes to editors:
(1) Moscovis SM et al, IL6 G-174C Associated With Sudden Infant Death Syndrome in a Caucasian Australian Cohort, Human Immunology 67, 819–825 (2006) (also see http://www.fsid.org.uk/blackwell.html); and Dashash M et al, Association of Sudden Infant Death Syndrome With VEGF and IL-6 Gene Polymorphisms, Human Immunology 67, 627–633 (2006) (also see http://www.fsid.org.uk/drucker-vegf.html)

(2) FSID’s Responding When a Baby Dies campaign, launched in 2000, calls for a standard protocol to improve professional responses to all sudden infant deaths has three key recommendations:
(i) A paediatrician, working in conjunction with the police, should visit each family within 24 hours of the death to take a complete medical history and offer initial support to the family
(ii) All post mortem examinations should be carried out by a paediatric pathologist, a specialist in babies’ disorders
(iii) A case discussion should be held with all the professionals who were involved with the family or the baby to review all available information, learn as much as possible about why that baby died, and plan future support for the family. 

About FSID: The Foundation for the Study of Infant Deaths is the UK’s leading baby charity working to prevent sudden deaths and promote infant health. Cot death is still the biggest killer of babies over one month old in the UK today, claiming around 300 infants’ lives every year – that’s more than road traffic accidents, leukaemia and meningitis put together. FSID funds research, supports bereaved families, promotes baby care advice, and works to improve investigations when a baby dies.

Press office: please contact Nicola Peckett, Head of Media, on 020 7227 5212 for more information or to set up an interview with an expert.

 

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