Early Swimming Increases Diarrhea Risk For Babies

NEUHERBERG, Germany, Oct. 5 -- Babies taken swimming in public pools in the first year of life have an increased risk of diarrhea, researchers here said.

An observational study of more than 2,100 children in Germany also showed a trend toward more otitis media and respiratory diseases, found Yvonne Schoefer, M.D., of Germany's National Research Center for Environment and Health, and colleagues.

On the other hand, there was no increased risk of atopic disease, Dr. Schoefer and colleagues reported in the October issue of the International Journal of Hygiene and Environmental Health.

The finding is important, Dr. Schoefer and colleagues said, because of an increase in parents and infants taking part in what's known as "baby-swimming."

"Babies and young children are more vulnerable to toxins because their lungs and immune systems have not yet matured," Dr. Schoefer said.

The idea of baby-swimming is not limited to Germany. USA Swimming this year launched a program aimed at getting kids into the water at a young age, as part of a nationwide water-safety initiative.

The German study looked at a prospective birth cohort of 2,192 six-year-olds and asked their parents when they had started to swim and what doctor-diagnosed illnesses they had suffered.

A multivariate regression analysis showed children who didn't swim regularly during their first year:

• Had a significantly lower risk of diarrhea. The odds ratio was 0.68, with a 95% confidence interval from 0.54 to 0.85.
• Appeared to have a lower risk of otitis media. The odds ratio was 0.81, but the 95% confidence interval - from 0.62 to 1.05 - crossed unity.
• Appeared to have a lower risk of respiratory diseases. The odds ratio was 0.85, but again the confidence interval -- 0.67 to 1.09 - crossed unity.
• Had a significantly higher risk of asthma by age six, although there was no other clear association with atopic dermatitis or hay fever. The odds ratio was 2.15, with a 95% confidence interval from 1.16 to 3.99.

Dr. Schoefer and colleagues noted that the link with asthma could well be explained by reverse causality - babies who had breathing difficulties might not be taken to the pool in the first place.

"The study shows that allowing babies to swim is possibly not as harmless with regard to infections as has been presumed till now," noted co-author Joachim Heinrich, Ph.D., also of the research center here.

"Clearly, swimming (in pools) is associated with a variety of different illnesses," commented Michael Beach, Ph.D., acting associate director for healthy water at the CDC in Atlanta.

The problem is two-fold, he said. On one hand, bathers often don't take showers before swimming, meaning they bring potential pathogens into what he called "communal bathing."

On the other hand, pools are often poorly maintained. A 2002 CDC study found that only half of pools that were inspected that year were free of health violations, although Dr. Beach cautioned that most violations were minor. Only about 8.5% of pools and 11% of spas were closed for health concerns, he said.

Interestingly, he added, there is no national standard for pool sanitation, although the CDC is in the process of drafting a set of model guidelines. Currently, though, most pools in the U.S. use between one and three parts per million of chlorine as a decontaminant.

The pools in the German study used about 0.2 parts per million of chlorine, the researchers said.