<?xml version=“1.0” encoding=“UTF-8”?> <Observation xmlns=“hl7.org/fhir”>

      <id value="vp-oyster"/>
      <meta>
  <security>
    <system value="http://terminology.hl7.org/CodeSystem/v3-ActReason"/>
    <code value="HTEST"/>
    <display value="test health data"/>
  </security>
</meta>
<identifier>
              <use value="official"/>
              <system value="http://sonomacounty.ca.gov/Health/Public-Health/Laboratory"/>
              <value value="20171014-1234"/>
      </identifier>
      <status value="preliminary"/>
      <!--   
  Observations are often coded in multiple code systems.
    - LOINC
              - or SNOMED
    -and/or the source system may provides its own "local" code, which may be less or more granular than LOINC.
      In this example there is only local codes
   -->
      <code>
              <!--   Should use a  proper LOINC code    -->
              <coding>
                      <system value="http://loinc.org"/>
                      <code value="41857-4"/>
                      <display value="Vibrio parahaemolyticus DNA [Presence] in Unspecified specimen by Probe and target amplification method"/>
              </coding>
              <!--   here is the local code   -->
              <coding>
                      <system value="http://sonomacounty.ca.gov/Health/Public-Health/Laboratory/test-codes"/>
                      <code value="VP MULTI PCR"/>
                      <display value="VP MULTI PCR"/>
              </coding>
              <text value="OYSTER TESTING"/>
      </code>
      <subject>
              <!--   reference value="Location/oyster-farm"/   -->
              <display value="Sonoma oyster farm"/>
      </subject>
      <effectiveDateTime value="2017-10-12"/>
      <issued value="2017-10-14T23:11:24Z"/>
      <performer>
              <reference value="Practitioner/f005"/>
              <display value="A. Langeveld"/>
      </performer>
      <!--   results of this Qualtiattive PCR is a choice of Positive/Negative and Inconclusive   -->
      <valueCodeableConcept>
              <!--   SNOMED CT codes   -->
              <coding>
                      <system value="http://snomed.info/sct"/>
                      <code value="10828004"/>
                      <display value="Positive (qualifier value)"/>
              </coding>
              <!--   local code translation   -->
              <coding>
                      <system value="http://sonomacounty.ca.gov/Health/Public-Health/Laboratory/result-codes"/>
                      <code value="POSITIVE"/>
                      <display value="POSITIVE"/>
              </coding>
              <text value="POSITIVE"/>
      </valueCodeableConcept>
      <interpretation>
              <coding>
                      <system value="http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"/>
                      <code value="A"/>
                      <display value="Abnormal"/>
              </coding>
      </interpretation>
      <specimen>
              <display value="Live Oysters Acc#20171014-1234"/>
      </specimen>
      <referenceRange>
              <text value="NEGATIVE"/>
      </referenceRange>

</Observation>