Final answer:
A unique patient identifier is required to locate a patient in a health information exchange organization, though patient consent is also important for privacy reasons.
Step-by-step explanation:
In order to locate a patient via a health information exchange organization, there must be primarily a unique patient identifier. This identifier ensures that the correct patient's health information is accessed among multiple healthcare providers.
Additionally, while patient consent is crucial for privacy and legal purposes, it is not the sole requirement for locating patient information. State-specific identifiers may be used for certain regional exchanges, and biometric authentication could enhance security, but these are not universally required for the location of patient data in a health information exchange.