Hepatitis C

[Previous][Table of Contents][Next]

Nationally notifiable since 1999

1.0 National Notification

Only confirmed cases of disease should be notified.

2.0 Type of Surveillance

Routine case-by-case notification to the federal level

3.0 Case Classification

3.1 Confirmed Case That Does Not Distinguish Acute from Chronic Infection

Detection of anti-hepatitis C antibodies ( anti-HCV) (positive anti-HCV tests should be confirmed by a second manufacturer’s EIA, immunoblot or NAT for HCV RNA).
OR
Detection of hepatitis C virus RNA

4.0 Laboratory Comments

Anti-HCV testing should not be performed in infants < 18 months of age as the anti-HCV may represent passive maternal antibody. As most infections occur at the time of childbirth, if testing for HCV RNA is considered, it should be delayed beyond 4 to 12 weeks to avoid false-negative HCV RNA test results. Cord blood should not be used because of potential cross-contamination with maternal antibody.

The HCV serologic window period is approximately 5-10 weeks, and it is estimated that 30% of acute infections may be missed if anti-HCV is the only marker of infection used during this period. HCV-RNA is detectable within two to three weeks of infection and, in the context of clinical illness, can identify acute HCV infection even in the absence of anti-HCV.

If HCV-RNA is used solely to confirm active infection, a repeat test is recommended.

Confirmation of acute infection requires a documented seroconversion, i.e. in a previously anti-HCV seronegative individual.

Approximately 25% (range 15% to 45%) of HCV infections will resolve spontaneously. These individuals will typically demonstrate anti-HCV without detectable HCV RNA (using a test with a lower limit of detection of 10-50 IU/mL)

Immunocompromised individuals may not develop anti-HCV (e.g. HIV infection with CD4 counts < 50). These individuals may need to undergo HCV RNA testing.

Positive anti-HCV tests should be confirmed by a second manufacturer’s EIA, immunoblot or NAT for HCV RNA.

5.0 Clinical Evidence

Acute clinical illness is characterized by a discrete onset of symptoms and jaundice or elevated serum aminotransferase levels. Chronic infections may present with disease flares with similar symptoms and signs.

6.0 ICD Code(s)

6.1 ICD-10 Code(s)

B17.1, B18.2

6.2 ICD-9 Code(s)

070.70, 070.71, 070.41, 070.44, 070.51, 070.54

7.0 Type of International Reporting

None

8.0 Comments

9.0 References

Case definitions for diseases under national surveillance. CCDR 2000;26(S3). Retrieved May 2008, from http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/00vol26/26s3/index.html

Date of Last Revision/Review:

September 2008