ACKNOWLEDGMENTS
We thank the pediatric practitioners Sabine Gross, Klaus Helm,
Malte Klarczyk, and Helmut Scho¨pfer for their collaboration and collection
of the stool specimens. We thank Annelies Crienen for excellent
technical assistance. We thank Gu¨nther Boehm for valuable advice
throughout the study.
This study was partially supported by a grant from the European
Commission through the PROEUHEALTH program (QLRT-2000-
01273