An association between sudden infant death syndrome and Helicobacter infection (2000; 83: 429-34)
A common bacterium implicated in peptic ulcers and heart disease may also be a cause of sudden unexpected death in babies (SIDS), suggests research in the Archives of Disease in Childhood.
Samples of tissue from the stomachs, wind pipes, and lungs of 32 babies up to seven months of age who had died of SIDS were analysed for the presence of two genes. The two genes, H pylori ureC and cagA, both indicate the likelihood of infection with Helicobacter pylori bacteria. The same tissue samples from eight babies who had died of other known causes were also examined for comparison.
One or both genes were present in one or more tissue samples among 28 of the 32 SIDS babies, a prevalence of 88 per cent. The genes were found in only one of the eight comparison babies. The prevalence of H pylori infection in developed countries runs at around 2 per cent.
It is very difficult to study how the bacterium might cause SIDS, because by definition the babies are dead when examined, and there are no obvious signs of SIDS before death. But, say the authors, H pylori infection produces an inflammatory response as well as large amounts of urease. And urease may induce the production of ammonia, which may be a critical factor.