1. A method of performing multi-domain surveillance, the method comprising: analyzing, via a computer processor, first streamed data to identify healthcare transaction signatures in the first streamed data; based on the first streamed data, creating a database of signature patterns across multiple domains of biosurveillance activity according to at least one region and based on time; analyzing, via a computer processor, second streamed data to identify healthcare transaction signature anomalies in the second streamed data, wherein the signature anomalies are identified by comparing healthcare transaction data contained in the second streamed data to the signature patterns in the database to yield a comparison; accessing data in the database from the multiple domains to identify a plurality of anomalies based on the comparison of the signature patterns; collecting the plurality of anomalies into a case for management, the case comprising a general container for the plurality of anomalies, sub-threshold and super-threshold scores in one of a single domain and multiple domains; and using corroborating evidence across the multiple domains to adjust a likelihood that an event associated with the case should be investigated.