Tuesday, December 05, 2006

Reasons why formula use is associated with increased salmonella

CBS reported on a new study by T Jones et al in Peds found that there was less risk of salmonella in breastfed babies. (see news article below - bolds were added)
May I share with you my surprise that they report that "the reason is not clear" for the lowered incidence among breastfed babies? Here are just a few reasons they may wish to consider:
1. Breastfed babies are protected against bacteria, including salmonella.
2. Breastfed babies are not exposed to formula, which is factory sterile, not sterile in the sense often assumed.
3. Any formula use would increase the chance of exposure to pathogens, so what surprises me is that it is not seen as often in those who use powdered formula as opposed to concentrate. I would be curious to review sample size and other variables associated with the choice of concentrate or powder. (Perhaps it is that open concentrate is stored in the refrigerator with other foods, while powder may be stored away from other foods? or is the concentrate in a can, in which case, the can opener may be a source of contamination?)

I am looking forward to reading the complete article, as perhaps the new reported misunderstood, and perhaps these are discusse inthe article..

CBS, Dec. 4, 2006 Salmonella Risk Factors For Babies (WebMD) Salmonella infection strikes babies more than any other age group, and many of these cases may be preventable. Researchers from the CDC, FDA, and seven state health departments report that news in Pediatrics. The scientists included Timothy Jones, MD, of Tennessee's health department. The study looked at 442 infants in eight states diagnosed with salmonella infection before their first birthday. There are different types of salmonella bacteria; Jones' team focused on nontyphoidal salmonella not linked to an outbreak.
The babies' most common symptoms were diarrhea and fever. They typically recovered within a week; however, two babies died as a result of their infection. The babies' parents completed extensive questionnaires about their child's animal exposure, food, and drink in the five days before salmonella infection. For comparison, the researchers gave similar questionnaires to parents of 928 babies the same age who were not affected by the bacteria.

Key Differences
The interviews showed six key differences between babies who got salmonella infection and those who didn't:

1. Breastfed babies were less likely to get salmonella infection. The reason for that isn't clear, but Jones' team says other studies have shown similar results.
2. Exposure to reptiles upped babies' chance of infection. Reptiles can carry salmonella. The CDC recommends that homes with kids under 5 years old not include reptiles.
3. Babies who rode in a shopping cart next to meat or poultry were more likely to get infected. Putting meat and poultry in a part of the cart away from kids might help; so might better packaging, the researchers note.
4. Babies over 3 months old who traveled outside the U.S. were more likely to get infected.
5. Babies who drank concentrated liquid infant formula were more likely to get salmonella infection. The reason for that isn't clear. Concentrated formula is sterile, but tainted water, unhygienic preparation, or poor storage of opened cans might be a problem, say the researchers.
Salmonella infection wasn't linked to ready-to-drink liquid infant formula or powdered infant formula.
6. Babies older than 6 months were more likely to get salmonella infection if they attended day care with a child who had diarrhea.

More studies are needed to make recommendations about salmonella prevention in babies, write the researchers.

SOURCES: Jones, T. Pediatrics, December 2006; vol 118: pp 2380-2387. News release, American Academy of Pediatrics.

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