[Table of Contents]

Volume: 25S2 - June 1999

Hepatitis C - Prevention and Control: A Public Health Consensus

Executive Summary

From October 14-16, 1998, the Laboratory Centre for Disease Control, Health Canada, held a national consensus conference in Ottawa: Hepatitis C - Prevention and Control: A Public Health Consensus. The aim was to review progress in addressing the public health recommendations of a 1994 conference, examine the present state of public health knowledge and action on hepatitis C virus (HCV) infection, and update the previous public health recommendations as necessary.

Participants were assigned to one of six working groups: surveillance; public health interventions; public health laboratory issues; injection drug user issues; education; and blood supply issues. Several important recommendations were as follows.

Surveillance

• Three different approaches are recommended to fulfil surveillance objectives:

  • routine case-by-case surveillance;
  • enhanced surveillance based in sentinel health units;

  • enhanced surveillance that targets specific locations, physician practices, or populations.

• Routine case-by-case surveillance should include collection of a minimum data set on all notified cases: date of birth or age, sex, location, time of onset (of acute symptomatic cases), and information on risk factors. The case definition for routine surveillance is a confirmed anti-HCV positive test result or a positive test for HCV RNA together with negative anti-HCV.

• The objectives of the sentinel health unit surveillance system are:

  • to determine newly identified/acquired infections;
  • to document clinical data, demographic information, risk factors, and costs more fully;
  • to provide follow-up to determine the natural history of the disease;
  • to support special studies;

  • to support evaluation of preventive programs.
    
    In this type of surveillance, the investigation of risk factors will be more extensive than for routine case-by-case surveillance. Other data elements will depend on the objectives of the sentinel study.

• The objectives of targeted enhanced surveillance are:

  • to identify newly acquired infections;
  • to monitor the burden of disease;
  • to support special studies;
  • to identify new emerging infections (agents) or risk factors;
  • to monitor seroconversion (repeated measures);
  • to provide information to determine the natural history of the disease;
  • to support targeted and cohort studies.

Public Health Interventions

• Public health has principal responsibility in primary prevention and surveillance.

• Primary care providers - general practitioners, family practitioners, nurses (especially in northern communities), street outreach programs, etc. - should offer testing for HCV infection to all people with risk factors, e.g. history of injection drug use. Testing needs to be done in the context of a comprehensive assessment of the individual's health needs; such needs may include testing for other infections, such as HIV, care for addiction, counselling, consideration of therapy for HCV, and follow-up.

• People with multiple sex partners should practise safer sex, e.g. by using barrier methods.

• In general, longstanding sexual partners do not need to change sexual practices if one of them is found to be infected with hepatitis C. However, partners need to be informed that although the risk is low it is not absent, and barrier methods are available.

• Data on risk factors should be collected: specifically, public health should follow up with the physician or primary care provider to determine whether there is a history of blood donation or receipt, and if so to share this information with the Canadian Blood Service or Héma-Québec (CBS/HQ).

• There is a need for public health and CBS/HQ to share database information (e.g. names of all HCV-positive people to be checked for past history of blood donation); a legal and ethical basis for this is required.

Public Health Laboratory Issues

• Despite the high specificity of current enzyme immunoassays (EIAs) in the detection of anti-HCV, false positive reactions will occur in populations with a low prevalence of infection. Therefore, all screening algorithms must include supplemental testing. A positive anti-HCV result is defined as a repeatedly reactive EIA and a positive supplemental test result. Only this result should be reported to the treating physician and public health authorities.

• Although EIA for the detection of anti-HCV should remain the test of choice for initial assessment of specimens in both immunocompetent and immunosuppressed persons, HCV nucleic acid detection (HCV RNA) should be performed in immunosuppressed patients who have a negative anti-HCV result but in whom HCV infection is suspected.

• Qualitative HCV RNA assays are not required for all anti-HCV positive patients. However, such testing may be useful in the following situations:

  • resolution of indeterminate HCV serology;
  • detection of infection in anti-HCV negative immunocompromised patients;
  • detection of HCV infection in the infant born to an anti-HCV positive mother (the optimal timing and frequency of monitoring requires data from prospective cohort studies);
  • documentation of viremia in anti-HCV positive patients with repeatedly normal liver function tests (for anxiety relief rather than to guide clinical management);

  • determination of the response to anti-viral treatment and the durability of that response.

• In patient management, pretreatment genotyping provides important information with respect to the risks/benefits and duration of treatment. Opportunities should be made available for accessing genotyping services in Canada.

• Pretreatment quantitative HCV RNA assays provide important information with respect to the risks/benefits of treatment and duration of therapy and should be made available.

Injection Drug User Issues

• Hepatitis C prevention programs should adhere to the harm reduction model as a health promotion strategy.

• A federal-provincial advisory committee should be created to ensure the implementation of a hepatitis C national action plan on injection drug user (IDU) issues; where there is significant overlap of issues, other bloodborne infectious diseases often found among drug users should also be addressed by the committee.

• Drug users themselves must be included at all levels of discussion and intervention. This involves the creation, provision of resources for and continuing support of drug user groups at federal/provincial/territorial and local levels.

• Since HCV infection is acquired very rapidly after initiation into injection drug use, prevention efforts should target above all (but not exclusively) new injection drug users and those who are contemplating injecting.

Education

• A federally led national awareness campaign should be developed as a priority.

• A national clearinghouse should be instituted for hepatitis C information as a central repository where information is readily available for health care providers, patients, and the general public, including a 1-800 telephone number (displayed on all information) and Internet access.

• Through discussion with universities/schools/professional organizations, case-based curricula should be developed for health care providers that take into account their knowledge and comfort when dealing with drug users and related issues.

• Educational materials should be developed with client groups and disseminated through existing networks, e.g. methadone clinics, needle exchange programs.

Blood Supply Issues

Targeted lookbacks^a, both retrospective and prospective, should be continued. When the HCV-infected donor is identified outside the blood service, complete identifying information should be provided to the blood service to permit lookback.

Traceback investigations^b on HCV-infected transfusion recipients should be continued so that other HCV-infected recipients may be identified through a subsequent lookback.

Recipient notification programs^c should be considered in jurisdictions where they have not been carried out. The final decision should be made on the basis of feasibility; regional, local, and provincial priorities; other methods available; and the likely yield of such activities (number of yet unidentified HCV-infected recipients).

Enabling legislation and regulations should be enacted in all jurisdictions to allow full and free sharing of information. Such legislation must safeguard the right to privacy and confidentiality of donors and recipients.

New mechanisms are required to ensure systematic coordination between public health and the Canadian Blood Service/Héma-Québec at three levels: federal; provincial/territorial (of high priority); and regional.

^a After identification by/to the blood service of an anti-HCV positive blood donor who has made previous donations, corresponding recipients are identified and advised to consult their family physicians about anti-HCV testing.
^b After identification of an anti-HCV positive blood recipient by/to the blood service, corresponding donors are identified and offered anti-HCV testing, and a targeted lookback is subsequently conducted for donors found to be anti-HCV positive.
^c After identification of all recipients of blood, e.g. from a specific institution for a specific time interval, such recipients are advised to consult their family physicians about anti-HCV testing.

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