This value set includes codes from the following code systems:

• The following codes from system: http://snomed.info/sct

  Code	Display	900000000000003001 (en-US)
  1290194006	Serokonversion innerhalb der letzten 6 Monate	Seroconversion (finding)

• The following codes from system: http://terminology.hl7.org/CodeSystem/v3-NullFlavor

  Code	Display
  ASKU	asked but unknown
  NASK	not asked