Tuberculosis (Mycobacterium tuberculosis)

2009 Case Definition

Clinical description

A chronic bacterial infection caused by Mycobacterium tuberculosis, characterized pathologically by the formation of granulomas. The most common site of infection is the lung, but other organs may be involved.

Case Verification Criteria

Overview

The calculation of case verification is hierarchical. A record that satisfies the criteria for more than one Case Verification value will be assigned the value that appears first in the hierarchy. For example, a record that meets the criteria for both Positive Culture (vercrit = '1') and Clinical Case Definition (vercrit = '3') will be assigned a value of Positive Culture (vercrit = '1').

Not a Verified Case (vercrit = '0') appears twice in the hierarchy because there are two sets of criteria that will result in a Case Verification value of Not a Verified Case (vercrit = '0'). They are:

1. Reason Therapy Stopped or Never Started is Not TB

2. Suspect Case (vercrit = '5') is changed by the user to Not a Verified Case (vercrit = '0')

Suspect Case (vercrit = '5') is the default Case Verification value assigned to all records created in the Surveillance module.

0 — Not a Verified Case

The record is assigned a Not a Verified Case (vercrit = '0') case verification value if Reason Therapy Stopped or Never Started is Not TB.

1 — Positive Culture

The record is assigned a Positive Culture (vercrit = '1') case verification value if either Sputum Culture or Culture of Tissue and Other Body Fluids is Positive.

1A — Positive NAA

The record is assigned a Positive NAA (vercrit = '1A') case verification value if Nucleic Acid Amplification Test Result is Positive.

2 — Positive Smear/Tissue

The record is assigned a Positive Smear/Tissue (vercrit = '2') case verification value if:

- Sputum Smear or Smear/Pathology/Cytology of Tissue and Other Body Fluids is Positive

-and-

- Sputum Culture and Culture of Tissue and Other Body Fluids are both either Not Done or Unknown

-AND-

- Nucleic Acid Amplification Test Result is either Not Done, Unknown or Indeterminate

3 — Clinical Case Definition

The record is assigned a Clinical Case Definition (vercrit = '3') case verification value if all the following are true:

- Site of TB Disease is not Missing or is not Site Not Stated .

- Sputum Culture and Culture of Tissue and Other Body Fluids are either Negative, Not Done, or Unknown

- Nucleic Acid Amplification Test Result is either Negative, Not Done, Unknown, or Indeterminate

- When Site of TB Disease is either Pulmonary, Pleural, or Lymphatic: Intrathoracic then either Initial Chest Radiograph or Initial Chest CT Scan or Other Chest Imaging Study is Abnormal,

- Tuberculin (Mantoux) Skin Test at Diagnosis or Interferon Gamma Release Assay for Mycobacterium tuberculosis at Diagnosis is Positive

- Initial Drug Regimen has at least two drugs marked Yes

If criteria to satisfy any of the previous case verifications are not met, the user has the option to overwrite the assigned case verification default value Suspect (vercrit = '5'), by selecting either Verified by Provider Diagnosis (vercrit = '4') or Not a Verified Case (vercrit = '0').

5 — Suspect

All new records are considered Suspect (vercrit = '5') until they meet the criteria for another Case Verification value or are overwritten by the user as either Verified by Provider Diagnosis (vercrit = '4') or Not a Verified Case (vercrit = '0').

4 — Verified by Provider Diagnosis (Overwrites Suspect)

The user elects to overwrite case verification default value Suspect (vercrit = '5') with Verified by Provider Diagnosis (vercrit = '4').

0 — Not a Verified Case (Overwrites Suspect)

The user elects to overwrite the Suspect (vercrit = '5') case verification default with Not a Verified Case (vercrit = '0').

See also:

Date Posted: