Research article

A review of interventions triggered by hepatitis A infected food-handlers in Canada

Andrea C Tricco^{* 1,2,3} , Ba' Pham^{* 1,2,4} , Bernard Duval⁵ , Gaston De Serres⁵ , Vladimir Gilca⁵ , Linda Vrbova⁶ , Andrea Anonychuk^1,7 , Murray Krahn^4,7 and David Moher²

¹Epidemiology and Biostatistics, GlaxoSmithKline Canada, Mississauga, Ontario, Canada

²Chalmers Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada

³Institute of Population Health, Ottawa, Ontario, Canada

⁴Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada

⁵Centre de Recherche du CHUQ, Universite Laval, Institut national de santé publique du Québec, Canada

⁶University of British Columbia, Department of Health Care and Epidemiology, Vancouver, British Columbia, Canada

⁷Division of Clinical Decision Making, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada

author email corresponding author email* Contributed equally

BMC Health Services Research 2006, 6:157doi:10.1186/1472-6963-6-157

Published:	8 December 2006

Abstract

Background

In countries with low hepatitis A (HA) endemicity, infected food handlers are the source of most reported foodborne outbreaks. In Canada, accessible data repositories of infected food handler incidents are not available. We undertook a systematic review of such incidents to evaluate the extent of viral transmission through food contamination and the scope of post-exposure prophylaxis (PEP) interventions.

Methods

A systematic search of MEDLINE and EMBASE was conducted to identify published reports of incidents in Canada. An expanded search of a news repository (i.e., transcripts from newspapers and newscasts) was also conducted to identify the location and timing of an incident, which was used to retrieve the related report by contacting local public health departments. Data pertaining to case identification, public health risk, PEP interventions, and associated costs was independently abstracted by two reviewers and summarized according to incidents with and without large PEP interventions.

Results

A total of 16 incidents were identified from 1998–2004. There were approximately 3 incidents requiring public notification per year. Only 12.5% of incidents were described in published reports, indicating that published data significantly underestimated the number of incidents and PEP interventions. Data pertaining to the remaining incidents was unpublished, sparse and highly dispersed at the local public health level.

Six of the 16 incidents required large PEP interventions to immunize on average 5000 potentially exposed individuals. Secondary transmission was low. Characteristics of incidents requiring large PEP interventions included potentially infectious food handlers working with uncooked food for a prolonged duration in high-volume grocery stores in high-density urban areas.

Conclusion

Infected food handlers with hepatitis A virus (HAV) requiring public notification are not infrequent in Canada. Published data severely underestimated the burden of PEP intervention. Better and consistent reporting at the local and national level as well as a national data repository should be considered for the management of future incidents.