ARCHIVED - A Review of Provincial/Territorial Strategies for Hepatitis A Pre- and Post-Exposure Prophylaxis

 

Volume 31-19
1 October 2005

Introduction

The hepatitis A virus (HAV) causes infection, resulting in liver inflammation. Typical symptoms include loss of appetite, fatigue, stomach pain, and dark urine, followed by the onset of jaundice. Infection is often asymptomatic in young children. The virus is transmitted via the fecal-oral route, particularly through exposure to food or water contaminated with feces that contains HAV.

The disease burden in Canada is estimated at 1.2 to 9.1 per 100,000 population (1992-2004), but has remained low in recent years (Personal Communication - Public Health Agency of Canada, 2005). This burden of disease is not evenly distributed across provinces and territories (P/Ts), and outbreaks occurring across Canada result in fluctuations from year to year. No treatment exists for HAV infection; however, since 1994, vaccine has been licensed for use in Canada. The National Advisory Committee on Immunization (NACI) provides recommendations for the use of HAV vaccine and immune globulin (Ig) for pre- and post-exposure prophylaxis and outbreak control.

Importantly, the delivery of HAV vaccine and Ig to high-risk groups or individuals differs across Canada. To obtain a national perspective on the epidemiology of HAV infection, it is necessary to understand the P/Ts vaccination policies and strategies. This summary presents the various HAV vaccination strategies across Canada, highlighting the differences among P/Ts, to facilitate information sharing for improved public health practice and prevention around HAV.

Methods

All Canadian P/Ts were surveyed via email to identify their current and past HAV prevention strategies (i.e. any changes that have occurred over the past 10 years). The survey comprised a series of questions on pre- and post-exposure prophylaxis, outbreak control, and general questions related to the epidemiology of HAV in each P/T. The appropriate person(s) responsible for vaccine coordination or communicable diseases in each P/T completed these surveys. Prior to the final draft, the collated responses were forwarded to all study participants for review.

Results

Table 1 (pre-exposure) and Table 2 (post-exposure) highlight the various pre- and post-vaccination strategies among P/Ts. For outbreak control (not shown in the tables), all study participants in the P/Ts responded that they use some form of HAV prophylaxis or that they would use it if an outbreak occurred. The majority stated that vaccine was the recommended choice, with Ig for infants aged < 1 year and for those with contraindications. Alberta, Quebec, Northwest Territories, and the Yukon use vaccine and Ig for post-exposure prophylaxis and outbreak control.

Discussion

Pre-exposure

With respect to pre-exposure prophylaxis, most P/Ts recommended HAV vaccine for some or all of the candidate high-risk groups that were outlined by NACI in the Canadian Immunization Guide(1) (Table 1). Interestingly, the P/Ts differ significantly on their recommendations – and particularly their funding allocation – for pre-exposure prophylaxis. Generally, two doses of vaccine are administered for pre-exposure prophylaxis, whereas, for post-exposure, only one dose may be publicly funded.

Most P/Ts recommended vaccine for the following high-risk groups:

  • men who have sex with men (MSM);
  • intravenous drug users (IDU);
  • persons with hemophilia A or B who receive plasma-derived replacement clotting factors;
  • individuals with chronic liver disease, including chronic hepatitis B (HBV) and hepatitis C (HCV) infections; and
  • travellers to countries where HAV is endemic.

There were two other notable differences: 1) Manitoba recommended vaccine for children undergoing bone marrow transplant, and 2) Quebec advocated vaccine for household contacts with an adopted child who arrived in Canada from an HAV endemic country < 3 months before (ideally to be vaccinated before the child?s arrival). All P/Ts fund vaccine for most, or all, of their recommended pre-exposure risk groups, except travellers. The only P/Ts whose policies encourage more travellers to be vaccinated are Newfoundland and Saskatchewan, offering vaccine to travellers on a cost-recovery basis. (Most public health offices are at the regional level.)

Almost all P/Ts have changed their HAV pre-exposure prophylaxis policies over the past 10 years, with most following the recommendations put forth by NACI(1). British Columbia (B.C.) and Quebec have media campaigns, such as television commercials, posters, and brochures to target high-risk groups – namely, MSM, IDU, those with chronic liver disease, and travellers – for pre-exposure prophylaxis. Targeted media campaigns in these provinces responded to past outbreaks and to generally higher rates of HAV than in other P/Ts. Similarly, the Yukon indicated that travellers are targeted for pre-exposure prophylaxis. Other P/Ts responded that pre-exposure prophylaxis is recommended on a case-by-case basis only.

Post-exposure and outbreak control

Most P/Ts primarily use HAV vaccine for post-exposure prophylaxis within 14 days post-exposure, except for individuals with contraindications and for those for which response may be inadequate, immunocompromised individuals or infants aged < 1 year (Table 2). The exceptions – Alberta, Quebec, Northwest Territories, and the Yukon – use either vaccine or Ig, depending on the time from exposure, or in some instances, they use a combination of Ig and vaccine. Recent NACI updates to recommendations indicate that vaccine is effective when given up to 2 weeks post-exposure(1). However, this qualification refers to vaccine when compared with no intervention, which may be insufficient evidence to justify the use of vaccine over Ig, thereby explaining the discrepancy between P/T policies(2). All P/Ts offer publicly funded post-exposure prophylaxis to household or close contacts of HAV cases, yet a second dose of vaccine (where applicable) is not funded by Alberta, B.C., Ontario, or Saskatchewan.

Post-exposure prophylaxis with vaccine has been recommended and funded in most P/Ts since the NACI recommendation in 2002 or before; however, some P/Ts, such as Alberta, have just recently (December 2004) implemented a strategy using vaccine for post-exposure prophylaxis. All P/Ts responded that post-exposure prophylaxis was recommended for household and close contacts of HAV cases or for others deemed at risk at the discretion of the medical officer of health. Only B.C. and Ontario have used targeted media to raise awareness among potential contacts who may be eligible for post-exposure prophylaxis. Likewise, Nova Scotia has used targeted media in the past for an outbreak of HAV among MSM and to raise awareness among persons with HCV when funding became available.

Epidemiology

Generally, the HAV rate in most P/Ts is decreasing, with the exception of some provinces, namely, Alberta, which experienced a substantial increase in rates from 2003 to 2004. When asked about barriers to HAV prevention, the responses depended on the incidence rates in the P/T. For those P/Ts with higher rates, travellers were a major barrier to prevention; their vaccine coverage was inadequate. Similarly, ensuring that high-risk groups receive their second dose provides an additional challenge. B.C., Manitoba, and Ontario mentioned food handlers as a major concern, because of the potential for widespread outbreaks and the requirement for large-scale distribution of post-exposure prophylaxis. The recent increase in Alberta, however, was unrelated to foreign travel. Quebec indicated that the delay in universal vaccination against HAV has been its primary barrier to HAV prevention and control.

The P/Ts were asked to rate their concern for HAV on a scale of one to 10. Responses ranged from a high of six to sept in B.C., Manitoba, and Alberta (in light of the recent increase and the discovery of a rare genotype) to a low of one in Newfoundland and the Yukon. The low level of concern is due primarily to the small numbers of HAV cases per year.

Most P/Ts that responded to the question replied that travellers are the highest risk group and should be the primary target for vaccination. On the other hand, HAV vaccination for travellers is not publicly funded, with the exception of Newfoundland and Saskatchewan (regional offices), where vaccine is available to travellers on a cost-recovery basis. Interestingly, in 2002, New Brunswick public health discontinued its involvement with travel clinics. Northwest Territories indicated that travellers, as well as HCV+ individuals, should be the primary target for vaccination. Nunavut responded that sewage workers, because of the nature of the collection process, were considered the highest risk group for HAV infection. Likewise, Saskatchewan indicated that the highest risk group for HAV infection was individuals living in low socio-economic status conditions, such as those individuals who live on First Nations reserves or in isolated communities without potable water supply. Low case numbers resulted in other P/Ts’ (e.g. New Brunswick) inability to define a high-risk group.

Currently, most P/Ts, with the exception of Quebec, do not recommend universal vaccination for HAV. Quebec stated that the combination vaccine, TwinrixTM, would be most acceptable in a universal vaccination scenario; however, this does not apply for those who have an existing infant HBV vaccination program. Most P/Ts stated that other programs besides HAV require more immediate attention and funding for policy changes. In addition, many stated that the number of HAV cases yearly did not justify a universal vaccination program, particularly at the expense of other immunization programs. Some P/Ts with lower rates (the Yukon, New Brunswick, and Prince Edward Island) indicated that HAV vaccine was definitely not a priority funding area.

Table 1. Provincial/territorial hepatitis A vaccine pre-exposure prophylaxis policies

P/T Vaccine recommended for Publicly funded (yes/no) Funded since (Date) Policy changes over the last 10 years Targeting through education or media
AB Persons with hemophilia A or B, chronic liver disease (incl. HBV+, HCV+, liver transplantation), IDU, MSM, occupational risk, endemic communities, incarcerated persons, and residents and staff of institutions for developmentally challenged Yes May 1, 2004 the groups listed were funded. Prior to May 1, 2004, only hemophiliacs were funded Letters to MOH, announce- ments in Alberta Medical Association Newsletter
B.C. A - Persons with hemophilia A or B*, HBV+ and HCV+ who are previously unimmunized*, other chronic liver disease or liver transplant*, (*and anti-HAV IgG negative), IDU, HIV+, MSM, inmates of provincial correctional facilities
B – travellers, military personnel, live/work in endemic areas, food handlers, multiple sex partners, residents and staff of institutions for developmentally challenged, occupational
Yes – those listed in part A only All funded as of 2001 1994 – hemophilia A or B
1998- IDU, HCV+
2001 – MSM, HBV+, chronic liver disease
Yes – MSM, IDU, HCV+ and HBV+ - posters, letters to physicians
MB Clotting factor deficiencies, pediatric bone marrow transplants, persons in communities with a confirmed HAV outbreak, chronic liver disease including HBV+ and HCV+, MSM and IDU Yes – except travellers Feb 2005 2000 – MSM, IDU, chronic liver disease publicly funded No – case by case only
ON MSM, IDU, individuals with chronic liver disease (including HBV+ and HCV+) Yes Sept 2003 Prior to Sept 2003, there were no recommendation Yes – MSM, IDU, chronic liver disease – education materials, physician letters
QC Residents of endemic communities, travellers, MSM, IDU (combined HAV/HBV vaccine), chronic HBV or HCV infection, household con- tacts with an adopted child from an HAV endemic country who arrived in Canada < 3 months ago, people who work with HAV, incarcerated people, zoo workers, patients in mental health clinics, waste water disposal workers Yes – HBV and HCV chronic infections, endemic communities with recurrent outbreaks, MSM, IDU 1999 All recommended since 1995-1996, but not funded until dates shown Yes – Travellers and MSM (commercials on TV, radio, leaflets)
Yes – Nunavik autochthon community 2002   Case by case through Public Health - HBV and HCV chroni- cally ill and Nunavik autochthon
No – travellers, other groups listed
NB HCV+ individuals Yes 1999 As of 2002 – public health dis- continued involvement in travel clinic immunizations No
NL Travellers, MSM, hemophiliacs, HCV+ Yes – except partial funding for travellers (cost recovery + admin fee) 1995 None No
NT HCV+ individuals, IDU, MSM, sewage workers, travellers Yes – except travellers 1995 HCV+ individuals and occupational risk added to recommendation Yes – awareness campaigns (especially HCV+ individuals)
NS Travellers, IDU, HCV infected, others in high-risk situations at the discretion of MOH Yes – except travellers 1998 Not previously funded for IDUs and HCV+ No
NU Travellers, occupational exposures, chronic liver disease, and residents and staff of institutions with increased risk of transmission Yes – except travellers and occupational exposures 1999-2000 N/A No
PE As per NACI recommendations Yes – HBV+, HCV+, liver transplantation, hemophiliacs 1995 None – updates as per CIG To physicians only
SK Residents aged 1 to 15 years living in northern health regions or on reserve; transplant recipients – bone marrow, solid organs; per- sons with chronic liver disease, HCV+, HIV+; hemophiliacs; travellers Yes – except travellers (provided on cost-recovery basis at most regional public health offices) 1998 – those on-reserve and northern children April 2002 – HCV+ The program for on-reserve and northern children was implemented following an outbreak that began in 1996 No
YT As per NACI recommendations Yes – except travellers 1995 None – updates as per CIG Yes – travellers
MSM = men who have sex with men; IDU = intravenous drug users; HAV = hepatitis A virus; HBV = hepatitis B virus; HCV = hepatitis C virus; HIV = human immunodeficiency virus;
MOH = medical officer of health; NACI = National Advisory Committee on Immunization; MHO = medical health officer; Ig = immune globulin; CIG = Canadian Immunization Guide

Table 2. Provincial/territorial hepatitis A vaccine post-exposure prophylaxis policies

P/T

Vaccine or Ig recommended

Publicly funded (yes/no)

Policy changes over the last 10 yrs

2nd dose funded

Targeting through education or media

AB

Depends on risk and time after exposure

Within 8 days of symptom onset in case:

1. Vaccine + Ig, if at risk of severe complications of HAV (liver disease, liver transplant, HBV carriers, anti-HCV positive)

2. Ig only for infants aged < 1 year, immunocompromised, vaccine contraindicated.

3. Vaccine only for all others not in category 1 or 2 NOT within 8 days of symptom onset in the case but within 14 days of last exposure to case:
-Ig only for all contacts (+ vaccine only for those eligible for pre-exposure prophylaxis)

Yes Prior to 1 Dec, 2004 – primarily Ig given within 2 wks of exposure, until Dec 2003 when vaccine was given on case-by-case basis. No* Letters to MOH, announce- ments in Alberta Medical Association Newsletter
B.C. Vaccine (1 dose within 14 days of exposure) Ig (infants aged < 6 months, immunocompromised and vaccine contraindicated) Yes 2002 – vaccine replaces Ig No* Yes – in some circumstances (food handlers - media, MSM - posters) otherwise case by case
MB Vaccine, Ig (aged < 1 year, vaccine contraindicated) Yes As per CIG Yes No – case by case
ON Vaccine (1 dose within 14 days of exposure) Yes 2002 – vaccine replaces Ig No* Yes – method depends on the situation
QC Both Vaccine ( # 7dayspost-exposure) Ig (infants aged < 12 months) Vaccine + Ig (within 8-18 days post-exposure) Vaccine + Ig (immunocompromised) Yes Prior to April 2002, no funding except for 1995-1996 MSM outbreak Yes (may vary depending on region – some only 1 dose funded*) No – case by case
NB Vaccine, Ig (aged < 1 year, contraindications) Yes As per NACI recommendations to use vaccine Yes (though #’s have been small to date) No
NL Vaccine, Ig (infrequently) Yes Vaccine replaced Ig Yes No
NT Both Yes More use of vaccine in outbreaks Yes Yes – HCV+ individuals only
NS Vaccine, Ig (aged < 1 year) Yes As per CIG Yes Yes – some for HCV, 1994 MSM outbreak
NU Vaccine, Ig (aged < 1year) Yes N/A Yes No
PE Vaccine Yes Changed to vaccine in past 4-5 years Yes No – case by case
SK Vaccine within 1-2 weeks post-exposure Ig (aged < 1 year, immunocompromised, con- traindications, vaccine unavailable or where deemed unaffordable) Yes As per CIG – however, vaccine was used in 1996 outbreak to augment the usual manage- ment (Ig) No* No
YT Vaccine or both Yes None Yes No – case by case
* A second dose of vaccine is not provided unless the individual is eligible for provincially funded pre-exposure prophylaxis.
MSM = men who have sex with men; IDU = intravenous drug users; HAV = hepatitis A virus; HBV = hepatitis B virus; HCV = hepatitis C virus; HIV = human immunodeficiency virus;
MOH = medical officer of health; NACI = National Advisory Committee on Immunization; MHO = medical health officer; Ig = immune globulin; CIG = Canadian Immunization Guide

Conclusion

Understanding how P/Ts differ with respect to HAV pre- and post-exposure prophylaxis strategies is an important step in improving public health practice around HAV prevention and control. Special attention should be paid to high-risk groups or to those who raise levels of concern, such as food handlers, to increase uptake of HAV vaccine. Additional consensus was reached around the need to emphasize ways to increase awareness and encourage travellers to receive pre-exposure prophylaxis. Although not all P/Ts have experienced an outbreak of HAV, there are valuable lessons to share with other P/Ts concerning post-exposure prophylaxis and outbreak control. The NACI guidelines on post-exposure prophylaxis and outbreak control have provided a foundation for Canadian public health authorities. Moreover, the national acceptance of these recommendations demonstrates the concerted efforts of conscientious public health authorities.

Acknowledgements

We would like to thank the following individuals for their valuable input: S. Virani, E. Sartison, D. Everett (Alberta Health and Wellness); M. Long, C. Beaudoin (Manitoba Health); L. Vrbova, L. Schiedel, D. Middleton (Ontario Ministry of Health and Long-Term Care); L. Cochrane (New Brunswick Health and Wellness); C. O’Keefe (Newfoundland and Labrador Health and Community Services); K. MacIsaac (Nova Scotia Department of Health); W. White (Health Social Services Government of the NWT); G. Osborne (Nunavut Department of Health and Social Services); L. Sweet (Prince Edward Island Health and Social Services); V. Gilca, B. Duval (Quebec Health and Social Services); M. Laurie, H. Bangura, H. Yang (Saskatchewan Health); and C. Hemsley (Yukon Department of Health and Social Services).

References

  1. National Advisory Committee on Immunization. Canadian Immunization Guide, 6th edition. Ottawa, ON: Health Canada, 2002.

  2. Sagliocca L, Amoroso P, Stroffolini T et al. Efficacy of hepatitis A vaccine in prevention of secondary hepatitis A infection: a randomised trial. Lancet 1999;353:1136-39.

Source: B Edgar, MHSc. JA Buxton, MBBS MHSc, Epidemiology Services BC Centre for Disease Control, Vancouver, B.C.


Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: