Researchers have pinpointed two common bacteria that may contribute to sudden infant death syndrome, or SIDS, even when infants show no sign of tissue damage.
Postmortem tests on more than 500 babies found high levels of Staphylococcus aureus and Escherichia coli in babies who died for unexplained reasons, a team from Great Ormond Street Hospital for Children in London reported today in the journal Lancet.
One explanation could be that the bacteria release deadly toxins that damage the young heart, lungs or nervous system.
But bacterial growth may also aggravate or be a secondary effect of other known risk factors, such as overheating, parental smoking and lying a child on his or her stomach.
SIDS is a leading cause of death in babies younger than a year old, yet its root cause remains a mystery.