Leptospirosis 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 leptospirosis 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 leptospirosis chief complaint free text terms:
  • The visit is included if it contains:
    1. A chief complaint related to disease name – (“leptos” or “liptos” or “lyptos” or “lepto” or “lipto” or “lypto” or “weil disease” or “weils disease”) OR
• Inclusion based on ICD-10 discharge diagnosis codes related to leptospirosis:
  • The visit is included if it contains:
    1. A discharge diagnosis code for leptospirosis – (A27) OR
• Inclusion based on SNOMED discharge diagnosis codes related to leptospirosis:
  • The visit is included if it contains:
    1. A discharge diagnosis code for leptospirosis – (77377001) OR
    2. A discharge diagnosis code for other forms of leptospirosis – (240673004 or 32266007 or 398067003 or 186956008 or 80194003 or 79309005 or 402959002 or 406589003) OR
    3. A discharge diagnosis code for conditions caused by Leptospirosis – (410476009 or 16038004 or 840440006 or 26275000 or 22312005 or 65267003 or 68013003 or 70543009 or 871841000 or 871842007)
• There are no exclusions in this query.