Bacteria Could be Linked to SIDS

The phenomenon known as Sudden Infant Death Syndrome is one of the leading causes of death for children under the age of one. Today, British researchers say they may have found that bacteria could be a contributing factor in these deaths.

The researchers found potentially dangerous bacteria such as E. coli and Staphylococcus in almost half of all babies that died suddenly without explanation over a decade at a London hospital. A SIDS expert at the U.S. National Institute of Child Health and Human Development, Marian Willinger, said that this could be another piece of the puzzle. The researchers did caution, however, that while they did find the bacteria in the SIDS babies, that does not mean that the bugs were completely responsible. Some doctors have long expected bacterial infections have played some role in SIDS.

A professor at the Great Ormond Street Hospital for Children where the study was conducted, Dr. Nigel Klein, said, "We don't know whether it's a cause or it's identifying another potential risk factor." He also stated that the higher level of bacteria may be evidence of another condition that could have killed the baby, such as the room might have been too hot or had poor ventilation, or their death could have been coincidental.

A diagnosis of SIDS means that no other cause of death could be found in an otherwise healthy baby who dies suddenly, and usually while they are sleeping. In the United States alone, SIDS claims the lives of more than 2,000 infants each year.

The researchers used samples of autopsies from 470 infants that died suddenly between 1996 and 2005. After examining the samples, they found dangerous bacteria in 181 babies. There were bacteria that were similar in about 14 of 53 of the infants who died of causes that were known, excluding those who died from bacterial infections. Most of the bacteria were found in the infants' spleen and lungs.

After delivery, mothers transfer some of their antibodies to help against infection to their infants. But by the time the babies are from 8 to 10 weeks of age, the maternal antibodies have almost run out and the infants typically have not started producing enough antibodies of their own. This could make the babies particularly vulnerable to bacterial infections, said a pathologist from Royal Infirmary in Lancaster James Morris. He also added, "The study is a good indicator that certain bacteria might be involved in causing sudden infant deaths."

Willinger suggested that infants that had bacterial infections might simply aggravate other risk factor for SIDS, such as babies that sleep on their stomachs or exposure to smoke. She also said that the combination of the bacteria with other co-factors might be pushing the infants over the edge."