This value set includes codes based on the following rules:

• Include these codes as defined in urn:oid:2.16.840.1.114222.4.5.274 version 20210722

  Code	Display
  PHC2288	Animal contact
  PHC2341	Lab isolate or specimen
  PHC2324	Undercooked meat
  PHC2303	Unpasteurized Dairy Product

• Include these codes as defined in http://snomed.info/sct version http://snomed.info/sct/731000124108/version/20210322

  Code	Display
  260413007	None
  787859002	Vaccine product

• Include these codes as defined in http://terminology.hl7.org/CodeSystem/v3-NullFlavor version 20090501

  Code	Display
  OTH	Other exposure source (specify)
  UNK	Unknown