While we were happy to see the issue of food safety in pregnancy
addressed in the April 2010 Motherisk Update, “Food-borne illness during
pregnancy” (1), we have concerns over some of the information presented
which contradicts public health messages on this topic.
The authors state that there is increased incidence of disease or
severe outcomes for the woman or neonate. However they recommend that
foods which may contain L. monocytogenes (deli meats, soft cheese),
Salmonella (eggs) or various bacteria, viruses and parasites (raw fish)
are safe for consumption if properly handled and stored and purchased from
a reputable supplier. These statements appear to contradict each other
and are not supported by the literature and public health recommendations
(2,3,4,5).
The authors do not provide references for many of their statements or
in certain instances use references that are out of date or not
representative of Canada. Non-published literature (e.g., government
documents, guidelines) and content experts have not been consulted to
identify recent Canadian outbreaks and public health programs and messages
related to this topic.
The authors suggest that improved standards and surveillance have
reduced the prevalence of contaminated foods in grocery stores and that
the frequency of outbreaks has decreased. It is not possible to say
whether the prevalence of contaminated foods and frequency of outbreaks
have decreased. Some literature suggests that the number of outbreaks and
the incidence of Salmonella and Listeria are increasing (6,7). Outbreaks
and food recalls (8) related to listeriosis and deli meats (9,10) or soft
cheese (11,12) and salmonellosis and eggs (7,13) continue to occur.
Food stored in a refrigerator allows the growth of Listeria which
prefers to multiply at these temperatures (14). Proper storage therefore
increases the risk of listeriosis. Proper handling of food (e.g., washing
hands) is recommended, however foods such as deli meats and cheeses may
already be contaminated when purchased. The consumer does not typically
take additional steps at home (e.g., cooking) to reduce potential
pathogens in such foods. Although purchasing food from a reputable
supplier with approved food safety plans is a good suggestion, even
reputable suppliers can have problems due to the ubiquitous nature of
these pathogens in a food processing environment (9,10). Additionally, it
is not possible for a pregnant woman to identify foods which have been
prepared or stored appropriately in restaurants and outside of the home
(e.g., flash frozen sushi, refrigerated eggs).
Finally, the authors have made some unfounded recommendations. The
Public Health Agency of Canada and most provincial/territorial and local
public health authorities in Canada and in many other countries recommend
the following (3,4,15,16):
• Pregnant women should avoid consuming unpasteurised milk and dairy
products, soft cheese (both pasteurized and unpasteurized), deli meats and
smoked fish due to the potential risk of listeriosis. Such foods can only
be safely eaten if heated to 74°C (165°F).
• Pregnant women and the general population should avoid consuming
raw and under-cooked eggs. They should store eggs in the refrigerator and
wash their hands and utensils/surfaces after contact with raw eggs. The
use of pasteurized egg products is recommended when a recipe calls for raw
eggs.
• Pregnant women and the general population should be aware that
consuming raw fish, shellfish or raw bivalves (e.g., oysters) increases
the risk of Vibrio, norovirus and other foodborne infections.
Research has shown that health-care providers may not provide
sufficient information about risks associated with food safety to pregnant
women and that messages should be improved and targeted (2,17,18,19).
There is on-going work in Canada to address this.
Motherisk is a valuable and credible source of information for
pregnant women and their health care providers. However, as evidenced by
this article and another published2 in the same issue of Canadian Family
Physician, further work is needed to improve food safety knowledge among
pregnant women and their health care providers.
Marsha Taylor,
Epidemiologist,
BC Centre for Disease Control
Dr. Eleni Galanis,
Physician Epidemiologist,
BC Centre for Disease Control
(1) Tam C, Erebara A, Einarson A. Food-borne illness during
pregnancy. Canadian Family Physician. April 2010; 56:341-343
(2) Kirkham C, Berkowitz J. Listeriosis in pregnancy. Canadian
Family Physician. April 2010; 56:158-166.
(3) Public Health Agency of Canada. Listeria Protecting Your
Pregnancy. (accessed at: http://www.phac-aspc.gc.ca/alert-
alerte/listeria/pp-pg-eng.php)
(4) Centers for Disease Control. Listeria and Pregnancy. (accessed
at: http://www.cdc.gov/ncbddd/pregnancy_gateway/infections-listeria.html)
(5) Kirkham C, Harris S, Gyzybowski S. Evidence-Based Prenatal Care:
Part 1-General Prenatal Care and Counseling Issues. American Family
Physician. 2005; 71(7).
(6) Lynch M, Painter J, Woodruff R, Braden C. Surveillance for
Foodborne Disease Outbreaks-United States, 1998-2002. MMWR. November
2006; 55(SS10):1-34
(7) BCCDC Annual Report of Communicable Disease-2008. BC Centre for
Disease Control (accessed at: http://www.bccdc.ca/NR/rdonlyres/59BFCFBB-
933D-4337-9305-E3E5FF30D272/0/EPI_Report_CDAnnual2008_20091202.pdf)
(8) Canadian Food Inspection Agency. Food Recall Alerts. (accessed
at: http://www.inspection.gc.ca/english/corpaffr/recarapp/recaltoce.shtml)
(9) Attaran A, MacDonald N, Stanbrook MB, Sibbald B, Flegel K,
Rajendra K, Hebert P. Listeriosis is the least of it. Canadian Medical
Association Journal. October 2008. 179(8).
(10) Report of the Independent Investigator into the 2008 Listeriosis
Outbreak. Government of Canada. July 2009
(11) Gaulin, C., Ramsay, D., Ringuette, L. and Ismaïl, J. First
documented outbreak of Listeria monocytogenes in Quebec, 2002. Canadian
Communicable Disease Report. 2003;29: 181-186.
(12) Clark, C. G., Farber, J., Pagotto, F., Ciampa, N., Doré, K.,
Nadon, C., Bernard,K., Ng, L.-K. and the CPHLN. Surveillance for Listeria
monocytogenes and listeriosis, 1995-2004. Epidemiology and Infection,
2009;12: 1-14.
(13) Christopher R. Braden. Salmonella enterica Serotype
Enteritidis and Eggs: A National Epidemic in the United States. Clinical
Infectious Diseases 2006;43:512–7
(14) Rocourt J, Cossart P. Listeria monocytogenes In: Doyle MP,
Beuchart LR, Montville TJ (eds.). Food Microbiology: Fundamentals and
Frontiers. Washington, DC: ASM Press. 1997. 337-352.
(15) Health Canada. It’s Your Health-Listeria and Food Safety.
(accessed at: http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/food-aliment/listeria-
eng.php)
(16) Canadian Food Inspection Agency. Food Safety Facts on Listeria.
(accessed at:
http://www.inspection.gc.ca/english/fssa/concen/cause/listeriae.shtml)
(17) Bondarianzadeh D, Yeatman H, Condon-Paoloni D. Listeria
education in pregnancy: lost opportunity for health professionals.
Australia and New Zealand Journal of Public Health. 2007; 31(5):468-74.
(18) Cates SC, Carter-Young HL, Conley S, O’Brien B. Pregnant Women
and Listeriosis: Preferred Educational Messages and Delivery Mechanisms.
Journal of Nutrition Education Behaviour. 2004; 36:121-27
(19) Morales S, Kendall PA, Medeiros LC, Hillers V, Schroeder M.
Health Care Providers’ Attitudes Toward Current Food Safety
Recommendations for Pregnant Women. Applied Nursing Research.
2004;17(3):178-186