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Surveillance and Reporting Guidelines for
Hepatitis C
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back to
Hepatitis C index page |
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Disease
Reporting |
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In Washington |
DOH receives
approximately 25 to 65 reports of non-A, non-B hepatitis
infections per year, the majority of which are caused by
hepatitis C virus (HCV). Non-A, non-B hepatitis is no longer
notifiable, however, acute and chronic infections with hepatitis
C became reportable in 2000.
An estimated 100,000 people
in Washington State may be infected with hepatitis C and about
250 deaths occur each year as a result of hepatitis C
infection. Approximately 7,000 case reports for chronic
hepatitis C have been recorded at DOH since reporting was
initiated in December 2000. The majority have been reported
based on a positive antibody test. |
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Purpose of Reporting and
Surveillance |
- To identify sources of transmission (e.g., an infected
health care worker) and to prevent further transmission from
such sources.
- To identify cases that may be a source of infection for
others (e.g., a sexual or drug contact) and to prevent further
disease transmission from such sources.
- To better understand the epidemiology of HCV and the
burden of morbidity from chronic infection.
- To make recommendations about and advocate for resources
for HCV treatment and targeted HCV screening.
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Reporting Requirements |
- Health care providers: notifiable to Local Health
Jurisdiction within one month
- Hospitals: notifiable to Local Health Jurisdiction within
one month
- Laboratories: no requirements for reporting
- Local health jurisdictions: notifiable to DOH within 7
days of case investigation completion or summary information
required within 21 days –
- Acute HCV: Communicable Disease Epidemiology
- Chronic HCV: Infectious Disease and Reproductive Health
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Case Definition for Surveillance |
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Acute Hepatitis C |
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Clinical Criteria for Diagnosis |
An illness with a) discrete
onset of symptoms consistent with viral hepatitis and , b)
jaundice or elevated serum aminotransferase levels. |
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Laboratory Criteria for Diagnosis |
- Serum aminotransferase levels >7 times the upper limit
of normal, and
- Immunoglobulin M (IgM) anti-HAV negative, and
- IgM anti-HBc negative or HbsAg negative, and
- Anti-HCV positive (repeatedly reactive) by enzyme
immunoassay (EIA), verified by an additional, more specific
assay (e.g., RIBA for anti-HCV or reverse transcriptase
polymerase chain reaction (RT-PCR) for HCV RNA, OR anti-HCV
by RIBA alone, OR HCV RNA positive alone.
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Case Definition |
- Confirmed: A case that meets the clinical case
definition and is laboratory confirmed.
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Chronic Hepatitis C |
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Clinical Criteria for Diagnosis |
Most HCV-infected persons are
asymptomatic. However, many have chronic liver disease, which
can range from mild to severe including cirrhosis, and/or liver
cancer. |
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Laboratory Criteria for Diagnosis |
- Anti-HCV positive (repeat reactive) by EIA, verified by
an additional more specific assay (e.g., RIBA for anti-HCV
or RT-PCR for HCV RNA), or
- Anti-HCV positive (repeat reactive) by EIA with average
signal to cut-off ratio ≥3.8., or
- Anti-HCV positive by RIBA alone, or
- HCV RNA positive.
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Case Definition |
- Probable. A case that is anti-HCV positive (repeat
reactive) by EIA and has alanine aminotransferase (ALT or
SGPT) values above the upper limit of normal, but the anti-HCV
EIA result has not been verified by an additional more
specific assay or the signal to cut-off ratio is unknown.
- Confirmed. A case that is laboratory confirmed.
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A. Description |
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1. Identification |
Onset is usually
insidious, with anorexia, vague abdominal discomfort, nausea and
vomiting; progression to jaundice is less frequent than with
hepatitis B. Although initial infection may be asymptomatic
(more than 90% of cases) or mild, a high percentage (between 50%
and 80%) will develop a chronic infection. Of these chronically
infected persons, about half will eventually develop cirrhosis
or cancer of the liver.
Diagnosis depends on
detecting antibody to the hepatitis C virus (anti-HCV). As of
the late 1990s, the only tests approved in the US for diagnosis
of HCV infection are those that measure anti-HCV. These tests
detect anti-HCV in up to 97% of infected patients, but do not
distinguish between acute, chronic, or resolved infection. As
with any screening test, positive predictive value of EIA for
anti-HCV varies depending on prevalence of infection in the
population and is low in populations with an HCV prevalence of
less than 10%. Supplemental testing with a more specific assay
(i.e., recombinant immunoblot assay [RIBATM]) of a specimen with
a positive EIA result limits reporting of false-positive
results. Supplemental test results might be positive, negative
or indeterminate. An anti-HCV positive person is defined as one
whose serologic results are EIA test positive and supplemental
test positive. Persons with a negative EIA test result or a
positive EIA and a negative supplemental test result are
considered uninfected, unless other evidence exists to indicate
HCV infection (e.g., abnormal ALT levels in immunocompromised
persons or persons with no other etiology for their liver
disease). |
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2. Infectious Agent |
The hepatitis C virus is an
enveloped RNA virus classified as a separate genus (Hepacavirus)
in the Flaviviridae family. At least six different genotypes and
greater than 90 subtypes of HCV exist. Evidence is limited
regarding differences in clinical features, disease outcome or
progression to cirrhosis or hepatocellular carcinoma (HCC) among
persons with different genotypes. However, differences do exist
in responses to antiviral therapy according to HCV genotypes. |
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3. Worldwide Occurrence |
Worldwide distribution. HCV
prevalence is directly related to the prevalence of persons who
routinely share injection equipment and to the prevalence of
poor parenteral practices in health care settings. WHO estimated
that as of the late 1990s, about 1% of the world's population
were infected with HCV. In Europe and North America the
prevalence of hepatitis C is between 0.5% and 2.0%; in parts of
Africa prevalence is over 4%. There may be close to 1.5 million
persons with HCV infections in Europe and close to 4 million in
the US. |
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4. Reservoir |
Humans; virus has been
transmitted experimentally to chimpanzees. |
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5. Modes of Transmission |
HCV is primarily parenterally
transmitted. Sexual transmission has been documented to occur
but is far less efficient or frequent than the parenteral route. |
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6. Incubation Period |
Ranges from 2 weeks to 6 months;
commonly 6-9 weeks. Chronic infection may persist for up to 20
years before the onset of cirrhosis or hepatoma. |
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7. Period of Communicability |
From one or more weeks before
onset of the first symptoms; may persist in most persons
indefinitely. Peaks in virus concentration appear to correlate
with peaks in ALT activity. |
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8. Susceptibility and Resistance |
Susceptibility is general. The
degree of immunity following infection is not known; repeated
infections with HCV have been demonstrated in an experimental
chimpanzee model. |
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B. Methods of Control |
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1. Preventive Measures |
General control measures
against HBV infection apply (see Hepatitis B, section B1).
Prophylactic IG is not effective. In blood bank operations,
all donors should be routinely screened for anti-HCV. In
addition, all donor units with elevated liver enzyme levels
and those positive for anti-HBc should continue to be
discarded. Routine virus inactivation of plasma derived
products, risk reduction counseling for persons uninfected but
at high risk (i.e., health care workers) and nosocomial
control activities need to be maintained. |
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2. Control of Patient, Contacts
and the Immediate Environment |
General control measures against
HBV apply. Available data suggest that postexposure prophylaxis
with IG is not effective in preventing infection. Interferon
alpha therapy has been shown to have an overall beneficial
effect in about 25% of chronic hepatitis C cases;
corticosteroids and acyclovir have not been effective. Studies
in patients receiving a combination of ribavirin and interferon
have demonstrated a substantial increase in sustained response
rates reaching 40%-50%. However, both of these medications have
significant side effects that require careful monitoring.
Ribavirin is a teratogen; thus pregnancy should be avoided
during therapy. |
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3. Epidemic Measures |
When two or more cases occur in
association with some common exposure, conduct a search for
additional cases. Institute strict aseptic techniques. If a
plasma derivative such as antihemophilic factor, fibrinogen,
pooled plasma or thrombin is implicated, withdraw the lot from
use and trace all recipients of the same lot in a search for
additional cases. |
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4. International Measures |
Ensure adequate virus
inactivation for all internationally traded biological products. |
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