NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.
Confirmatory laboratory evidence:
For probable maternal cases:
There is currently insufficient data available to support a routine recommendation for criteria to distinguish a new case of listeriosis from prior reports or notifications. Duplicate or recurring reports of listeriosis in an individual should be evaluated on a case by case basis.
Pregnancy loss and intrauterine fetal demise are considered maternal outcomes and would be counted as a single case in the mother.
Cases in neonates and mothers should be reported separately when each meets the case definition. A case in a neonate is counted if live-born.