Giardiasis v1

Query purpose: 

Created by the CDC National Syndromic Surveillance Program (NSSP) for use with emergency department data to develop queries for all National Notifiable Diseases defined by the National Notifiable Disease Surveillance System (NNDSS). Please note that while the disease queries are developed using the NNDSS case definition as the basis for identifying patient visits of interest, the queried patient visits themselves may or may not represent a case patient in NNDSS and further public health investigation will most often be required. This query is intended to be a version 1 and may be further improved upon by the NSSP community of practice in the future. This query is intended to be narrow and capture visits with specific terms to support greater monitoring and actionable public health data. More complex and/or broader queries may exist that more broadly capture symptoms or travel-based terms.

How it was developed: 

1. The CDC team used the NNDSS case definition of giardiasis to identify diagnostic codes (International Classification of Diseases, 9th & 10th Revision (ICD-9-CM, ICD-10-CM), SNOMED Clinical Terms (CT)) and chief complaint free-text for syndrome development.
2. The codes and free text were then categorized as inclusion or exclusion terms. These terms were formatted for querying in ESSENCE.
3. Text analysis was conducted on the initial query to find additional inclusion or exclusion terms.
4. The query was cross-checked internally as NSSP and by CDC subject matter experts as needed.

How it works:

The Chief Complaint Discharge Diagnosis (CCDD) parsed field is used to query both the discharge diagnosis codes and chief complaint free text, and exclusions are incorporated as necessary.

• Inclusion based on giardiasis chief complaint free text terms:
  • The visit is included if it contains:
    1. A chief complaint related to disease name – (“giardia”) OR
    2. A chief complaint related to alternative disease names – (“lambliasis” or “beaver fever”) OR
• Inclusion based on ICD-10 discharge diagnosis codes related to giardiasis:
  • The visit is included if it contains:
    1. A discharge diagnosis code for Giardiasis – (A07.1) OR
• Inclusion based on ICD-9 discharge diagnosis codes related to giardiasis:
  • The visit is included if it contains:
    1. A discharge diagnosis code for Giardiasis – (007.1) OR
• Inclusion based on SNOMED discharge diagnosis codes related to giardiasis:
  • The visit is included if it contains:
    1. A discharge diagnosis code for Giardiasis – (58265007) OR
    2. A discharge diagnosis code for conditions caused by Giardiasis – (10679007 or 1193805002 or 1163109001 or 1163081002 or 1193804003)
• All of the above must exclude:
  • A chief complaint related to history of Giardiasis – (“history giardia”, “history of giardia”)