Human Breastmilk in Young Children With Norovirus Infection of the Gut

Inclusion Criteria: * Children with at least two stool samples taken at least 7 days apart that are positive for norovirus * Child has an underlying disease or has received immunosuppressive medication or chemotherapy such that clearance of norovirus is expected to be impaired. Exclusion Criteria: * The presence of other pathogens causing diarrhea that have specific treatments does not preclude enrollment. However, specific treatment should be offered in addition to human milk.