Public Health Notice - Outbreak of E. coli infections linked to romaine lettuce

December 6, 2018 – Update

This update reflects three additional illnesses that have been reported in the outbreak since our last update on November 29, 2018. In Canada, there are now 27 illnesses under investigation. The Public Health Agency of Canada continues to advise residents in the affected provinces of Ontario, Quebec and New Brunswick to avoid eating romaine lettuce and salad mixes containing romaine lettuce, unless consumers can identify that the romaine lettuce being purchased did not come from an affected growing region in California outlined on the U.S. FDA’s website.

Why you should take note

The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency (CFIA), Health Canada, as well as the United States Centers for Disease Control and Prevention (U.S. CDC) and the United States Food and Drug Administration (U.S. FDA), to investigate an outbreak of E. coli infections in Ontario, Quebec, New Brunswick, and several U.S. states.

In Canada, based on the investigation findings to date, exposure to romaine lettuce has been identified as a source of the outbreak. Through a collaborative investigation between public health and food safety partners in Canada and the United States preliminary traceback information indicates that the contaminated romaine lettuce was harvested in California. Specifically, the U.S. FDA has indicated that the romaine lettuce was harvested in the Central Coast growing regions of northern and central California. It has been determined that romaine lettuce grown in Canada, including hydroponic romaine lettuce and romaine lettuce grown in green-houses, is not associated with this outbreak. The investigation is ongoing to determine the cause of contamination in romaine lettuce coming from the affected harvest regions in California.

As of November 27, 2018 the CFIA has implemented new actions to ensure affected product is not available in the Canadian marketplace and to verify that romaine lettuce from the areas identified in the U.S. FDA's investigation is not being admitted to Canada. The CFIA has advised distributors, importers, restaurants, retailers, and institutions not to distribute, import, sell, serve, or use romaine lettuce and products containing romaine lettuce harvested in the Central Coast growing regions of northern and central California during the 2018 growing season, as identified by the U.S. FDA.

While these actions are being implemented in the Canadian marketplace, the Public Health Agency of Canada continues to advise residents in the affected provinces of Ontario, Quebec and New Brunswick to avoid eating romaine lettuce and salad mixes containing romaine lettuce, unless consumers can identify that the romaine lettuce being purchased did not come from an affected growing region in California outlined on the U.S. FDA’s website. Retailers and industry partners are now working to bring romaine lettuce into the Canadian marketplace from growing regions not associated with the outbreak and to help consumers easily identify the origin of romaine lettuce in the Canadian marketplace.  Canadians who are travelling to the U.S., or who shop for groceries across the border and purchase romaine lettuce in the U.S. are advised to follow the U.S. CDC's advice for U.S. consumers found on their website.

The outbreak investigation is ongoing, and this public health notice will be updated as the Canadian investigation evolves.

How does lettuce become contaminated with E. coli

E. coli are bacteria that live naturally in the intestines of cattle, poultry and other animals. A common source of E. coli illness is raw fruits and vegetables that have come in contact with feces from infected animals. Leafy greens, such as lettuce, can become contaminated in the field by soil, water, animals or improperly composted manure. Lettuce can also be contaminated by bacteria during and after harvest from handling, storing and transporting the produce. Contamination in lettuce is also possible at the grocery store, in the refrigerator, or from counters and cutting boards through cross-contamination with harmful bacteria from raw meat, poultry or seafood. Most E. coli strains are harmless to humans, but some varieties cause illness.

Investigation summary

In Canada, as of December 6, 2018, there have been 27 confirmed cases of E. coli illness investigated in Ontario (4), Quebec (19), New Brunswick (1), and British Columbia (3). The illnesses in British Columbia were related to travel to Quebec, Ontario and the United States. Individuals became sick between mid-October and early November 2018. Nine individuals have been hospitalized, and two individuals suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 2 and 93 years of age. The majority of cases (52%) are male.

Most of the individuals who became sick reported eating romaine lettuce before their illnesses occurred. Individuals reported eating romaine lettuce at home, as well as in prepared salads purchased at grocery stores, or from menu items ordered at restaurants and fast food chains.

Laboratory analysis indicates that the illnesses reported in this outbreak are genetically related to illnesses reported in a previous E. coli outbreak from December 2017 that affected consumers in both Canada and the U.S. This tells us that the same strain of E. coli is causing illness in Canada and the US as was seen in 2017 and it suggests there may be a reoccurring source of contamination. Investigators are using evidence collected in both outbreaks to help identify the possible cause of the contamination in these events.

The CFIA is working with public health officials and the U.S. FDA to determine the source of the contamination in the romaine lettuce that was harvested in the Central Coast growing regions of northern and central California. As part of the food safety investigation, romaine lettuce was sampled and tested. To date, all products that have been tested have been negative for E. coli. The CFIA has advised industry not to import, distribute, sell, serve, or use romaine lettuce from the suspect areas in California identified in the U.S. FDA's investigation, and they are working to verify that these new actions are being implemented in the Canadian marketplace.

Who is most at risk

This outbreak strain known as E. coli O157 is more likely than other strains to cause severe illness. Pregnant women, those with weakened immune systems, young children and older adults are most at risk for developing serious complications.

Most people who become ill from an E. coli infection will recover completely on their own. However, some people may have a more serious illness that requires hospital care, or long-lasting health effects. In rare cases, some individuals may develop life-threatening symptoms, including stroke, kidney failure and seizures, which could result in death. It is possible for some people to be infected with the bacteria and to not get sick or show any symptoms, but to still be able to spread the infection to others.

What you should do to protect your health

It is difficult to know whether a product is contaminated with E. coli because you can't see, smell or taste it. Romaine lettuce can have a shelf life of up to five weeks, and therefore it is possible that contaminated romaine lettuce purchased over the last few weeks may still be in your home.

As of November 27, 2018 the CFIA has implemented new actions to ensure affected product is not available in the Canadian marketplace and to prevent the import of romaine lettuce from the affected U.S. growing region into Canada. While these actions are being implemented in the Canadian marketplace, the Public Health Agency of Canada continues to advise residents in the affected provinces of Ontario, Quebec, and New Brunswick to avoid eating romaine lettuce and salad mixes containing romaine lettuce, unless consumers can identify that the romaine lettuce being purchased did not come from an affected growing region in California outlined on the U.S. FDA’s website. Retailers and industry partners are now working to bring romaine lettuce into the Canadian marketplace from growing regions not associated with the outbreak and to help consumers easily identify the origin of romaine lettuce in the Canadian marketplace.

Residents in affected provinces are also advised to discard any romaine lettuce in their home purchased before November 29, 2018, and to properly wash and sanitize any containers or bins that have come in contact with romaine lettuce. Canadians who are travelling to the U.S., or who shop for groceries across the border and purchase romaine lettuce in the U.S. are advised to follow the U.S. CDC's advice for U.S. consumers found on their website.

This advice includes all types or uses of romaine lettuce, such as whole heads of romaine, hearts of romaine, and bags and boxes of precut lettuce and salad mixes that contain romaine,  including baby romaine, spring mix, and Caesar salad.

Symptoms

People infected with E. coli can have a wide range of symptoms. Some do not get sick at all, though they can still spread the infection to others. Others may feel as though they have a bad case of upset stomach. In some cases, individuals become seriously ill and must be hospitalized.

The following symptoms can appear within one to ten days after contact with the bacteria:

  • nausea
  • vomiting
  • headache
  • mild fever
  • severe stomach cramps
  • watery or bloody diarrhea

Most symptoms end within five to ten days. There is no real treatment for E. coli infections, other than monitoring the illness, providing comfort, and preventing dehydration through proper hydration and nutrition. People who develop complications may need further treatment, like dialysis for kidney failure. You should contact your health care provider if symptoms persist.

What the Government of Canada is doing

The Government of Canada is committed to food safety. The Public Health Agency of Canada leads the human health investigation into an outbreak, and is in regular contact with its federal, provincial and territorial partners to monitor the situation and to collaborate on steps to address an outbreak.

Health Canada provides food-related health risk assessments to determine whether the presence of a certain substance or microorganism poses a health risk to consumers.

The Canadian Food Inspection Agency conducts food safety investigations into the possible food source of an outbreak.

The Government of Canada will continue to update Canadians as new information related to this investigation becomes available.

Epidemiological information

The figure below is an epi curve for this outbreak. This information is used by outbreak investigators to show when illnesses began, when they peak, and when they trail off. It can take several weeks from the time a person becomes ill to when this illness is reported and testing confirms a link to the outbreak. Data are available for 27 cases.

Figure 1: Number of people infected with E. coli O157

Figure 1: Text description
Table 1 - Number of people confirmed to be infected with E. coli O157 by week of illness onset or isolation date
Week of symptom onset or isolation date Number of cases
2018-10-07 0
2018-10-14 6
2018-10-21 9
2018-10-28 12
2018-11-04 0
2018-11-11 0

Additional information

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Investigation History

Public Health Notice Update - November 29, 2018

This update reflects additional findings and details about the ongoing outbreak investigation. The ongoing collaborative investigation has linked romaine lettuce harvested in a specific growing region of California to the outbreak.

As of November 27, 2018, the Canadian Food Inspection Agency (CFIA) has implemented new actions to ensure affected product is not available in the Canadian marketplace and to prevent the import of romaine lettuce from the affected U.S. growing region into Canada. While these actions are being implemented in the Canadian marketplace, the Public Health Agency of Canada continues to advise residents in the affected provinces of Ontario, Quebec and New Brunswick to avoid eating romaine lettuce and salad mixes containing romaine lettuce, unless consumers can identify that the romaine lettuce being purchased did not come from an affected growing region in California outlined on the U.S. FDA’s website.

On November 26, 2018 the U.S. Food and Drug Administration and U.S. Centers for Disease Control and Prevention, as well as the Canadian Food Inspection Agency released statements related to the ongoing outbreak investigation. This notice will continue to be updated as the outbreak investigation evolves.

Strains are harmless to humans, but some varieties cause illness.

Investigation summary

In Canada, as of November 29, 2018, there have been 24 confirmed cases of E. coli illness investigated in Ontario (4), Quebec (17), New Brunswick (1), and British Columbia (2). The illnesses in British Columbia were related to travel to Quebec, Ontario and the United States. Individuals became sick between mid-October and early November 2018. Eight individuals have been hospitalized, and one individual suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 5 and 93 years of age. The majority of cases (54%) are female.

Public Health Notice Update - November 26, 2018

There is new information about the ongoing outbreak investigation from the U.S. Food and Drug Administration and U.S. Centers for Disease Control and Prevention, as well as new actions being taken by the Canadian Food Inspection Agency. At this time, there have been no changes to the public health advice for Canadians. This notice will continue to be updated as the outbreak investigation evolves.

Why you should take note

The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency, Health Canada, as well as the United States Centers for Disease Control and Prevention (U.S. CDC) and the United States Food and Drug Administration (U.S. FDA), to investigate an outbreak of E. coli infections in Ontario, Quebec, New Brunswick, and several U.S. states.

In Canada, based on the investigation findings to date, exposure to romaine lettuce has been identified as a source of the outbreak, but the cause of contamination has not been identified. Laboratory analysis indicates that the illnesses reported in this outbreak are genetically related to illnesses reported in a previous E. coli outbreak from December 2017 that affected consumers in both Canada and the U.S. This tells us that the same strain of E. coli is causing illness in Canada and the US as was seen in 2017 and it suggests there may be a reoccurring source of contamination. Investigators are using evidence collected in both outbreaks to help identify the possible cause of the contamination in these events.

The current outbreak appears to be ongoing as illnesses linked to romaine lettuce continue to be reported. These recent illnesses indicate that contaminated romaine lettuce may still be on the market, including in restaurants, grocery stores and any establishments that serve food. At this time, the investigation evidence in Ontario, Quebec, and New Brunswick suggests that there is a risk of E. coli infections associated with eating romaine lettuce.

As the risk is ongoing, the Public Health Agency of Canada is advising individuals in Ontario, Quebec, and New Brunswick to avoid eating romaine lettuce and salad mixes containing romaine lettuce until more is known about the outbreak and the cause of contamination. Residents in impacted provinces are also advised to discard any romaine lettuce in their home, and to properly wash and sanitize any containers or bins that have come in contact with romaine lettuce.

Currently, there is no evidence to suggest that residents in other parts of Canada are affected by this outbreak. The U.S. CDC has also issued communications with similar advice for U.S individuals. The outbreak investigation is ongoing, and this public health notice will be updated as the Canadian investigation evolves.

Investigation summary

In Canada, as of November 23, 2018, there have been 22 confirmed cases of E. coli illness investigated in Ontario (4), Quebec (17), and New Brunswick (1). Individuals became sick between mid-October and early November 2018. Eight individuals have been hospitalized, and one individual suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 5 and 93 years of age. The cases are evenly distributed among male and female individuals.

Most of the individuals who became sick reported eating romaine lettuce before their illnesses occurred. Individuals reported eating romaine lettuce at home, as well as in prepared salads purchased at grocery stores, or from menu items ordered at restaurants and fast food chains.

The Canadian Food Inspection Agency (CFIA) is working with public health officials and the U.S. FDA to determine the source of the romaine lettuce that ill individuals were exposed to. As part of the food safety investigation, romaine lettuce is being sampled and tested. To date, all products that have been tested have been negative for E. coli. As no contaminated product has been found in the marketplace and the source of the contamination has not been identified, there have been no product recalls in Canada or the U.S associated with this outbreak. If a specific brand or source of romaine lettuce is identified in Canada the CFIA will take the necessary steps to protect the public, including recalling the product as required.

What you should do to protect your health

It is difficult to know whether a product is contaminated with E. coli because you can't see, smell or taste it. Romaine lettuce can have a shelf life of up to five weeks, and therefore it is possible that contaminated romaine lettuce purchased over the past few weeks may still be in your home.

Restaurant and retailers may also still be selling romaine lettuce products. Consumers are advised to use the information in this public health notice to help make informed decisions about their own personal health situations. Individuals in Ontario, Quebec and New Brunswick should avoid eating romaine lettuce and salad mixes containing romaine lettuce until more is known about the outbreak and the cause of contamination. Residents in impacted provinces are also advised to discard any romaine lettuce in their home, and to properly wash and sanitize any containers or bins that have come in contact with romaine lettuce.

This advice includes all types or uses of romaine lettuce, such as whole heads of romaine, hearts of romaine, and bags and boxes of precut lettuce and salad mixes that contain romaine, including baby romaine, spring mix, and Caesar salad.

Public Health Notice Update - November 23, 2018

This notice has been updated to include three additional cases of E. coli linked to the outbreak. There are now 22 confirmed cases in Canada across three provinces: Ontario, Quebec and New Brunswick. Additional public health advice to residents in impacted provinces is also included in this updated notice.

Public Health Notice Update - November 21, 2018

This notice has been updated to include an additional case of E. coli linked to the outbreak that has been reported in New Brunswick. There are now 19 confirmed cases in Canada. The public health advice included in this notice now applies to residents in New Brunswick.

Investigation summary

In Canada, as of November 21, 2018, there have been 19 confirmed cases of E. coli illness investigated in Ontario (3), Quebec (15), and New Brunswick (1). Individuals became sick between mid-October and early November 2018. Eight individuals have been hospitalized, and one individual suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 5 and 93 years of age. The majority of cases (53%) are female.

Most of the individuals who became sick reported eating romaine lettuce before their illnesses occurred. Individuals reported eating romaine lettuce at home, as well as in prepared salads purchased at grocery stores, or from menu items ordered at restaurants and fast food chains.

The Canadian Food Inspection Agency is working with public health officials and the U.S. FDA to determine the source of the romaine lettuce that ill individuals were exposed to. If contaminated food products are identified in Canada, they will take the necessary steps to protect the public, including recalling the product as required. Currently, there are no Food Recall Warnings associated with this outbreak.

What you should do to protect your health

It is difficult to know whether a product is contaminated with E. coli because you can't see, smell or taste it. Romaine lettuce can have a shelf life of up to five weeks, and therefore it is possible that contaminated romaine lettuce purchased over the past few weeks may still be in your home. Restaurant and retailers may also still be selling romaine lettuce products. Consumers are advised to use the information in this public health notice to help make informed decisions about their own personal health situations. Individuals in Ontario, Quebec, and New Brunswick should avoid eating romaine lettuce and salad mixes containing romaine lettuce until more is known about the outbreak and the cause of contamination.

This outbreak is a reminder that romaine lettuce and other leafy greens can be a carrier of E. coli. It is important to always follow safe food handling practices if you are preparing, handling, and serving any type of lettuce. The following tips will help reduce your risk of an E. coli infection, but they will not fully eliminate the risk of illness.

  • Wash your hands thoroughly with warm water and soap for at least 20 seconds, before and after handling lettuce.
  • Unwashed lettuce, including whole heads of lettuce sold in sealed bags, should be handled and washed using these steps:
    • Discard outer leaves of fresh lettuce.
    • Wash unpackaged lettuce under fresh, cool running water. There is no need to use anything other than water to wash lettuce. Washing it gently with water is as effective as using produce cleansers.
    • Keep rinsing your lettuce until all of the dirt has been washed away.
    • Don't soak lettuce in a sink full of water. It can become contaminated by bacteria in the sink.
    • Store lettuce in the refrigerator for up to seven days. Discard when leaves become wilted or brown.
    • Use warm water and soap to thoroughly wash all utensils, countertops, cutting boards and storage containers before and after handling lettuce to avoid cross-contamination.
  • Ready-to-eat lettuce products sold in sealed packages and labelled as washed, pre-washed or triple washed do not need to be washed again. These products should also be refrigerated and used before the expiration date.
Public Health Notice - November 20, 2018

Why you should take note

The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency, Health Canada, as well as the United States Centers for Disease Control and Prevention (U.S. CDC) and the United States Food and Drug Administration (U.S. FDA), to investigate an outbreak of E. coli infections in Ontario and Quebec, and several U.S. states.

In Canada, based on the investigation findings to date, exposure to romaine lettuce has been identified as a source of the outbreak, but the cause of contamination has not been identified. Laboratory analysis indicates that the illnesses reported in this outbreak are genetically related to illnesses reported in a previous E. coli outbreak from December 2017 that affected consumers in both Canada and the U.S. This tells us that the same strain of E. coli is causing illness in Canada and the US as was seen in 2017 and it suggests there may be a reoccurring source of contamination. Investigators are using evidence collected in both outbreaks to help identify the possible cause of the contamination in these events.

The current outbreak appears to be ongoing as illnesses linked to romaine lettuce continue to be reported. These recent illnesses indicate that contaminated romaine lettuce may still be on the market, including in restaurants, grocery stores and any establishments that serve food. At this time, the investigation evidence in Ontario and Quebec suggests that there is a risk of E. coli infections associated with eating romaine lettuce.

As the risk is ongoing, the Public Health Agency of Canada is advising individuals in Ontario and Quebec to avoid eating romaine lettuce and salad mixes containing romaine lettuce until more is known about the outbreak and the cause of contamination. Currently, there is no evidence to suggest that residents in other parts of Canada are affected by this outbreak. The U.S. CDC has also issued communications with similar advice for U.S individuals in affected states. The outbreak investigation is ongoing, and this public health notice will be updated as the Canadian investigation evolves.

Investigation summary

In Canada, as of November 20, 2018, there have been 18 confirmed cases of E. coli illness investigated in Ontario (3) and Quebec (15). Individuals became sick between mid-October and early November 2018. Six individuals have been hospitalized, and one individual suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 5 and 93 years of age. The majority of cases (56%) are female.

Most of the individuals who became sick in Ontario and Quebec reported eating romaine lettuce before their illnesses occurred. Individuals reported eating romaine lettuce at home, as well as in prepared salads purchased at grocery stores, or from menu items ordered at restaurants and fast food chains.

The Canadian Food Inspection Agency is working with public health officials and the U.S. FDA to determine the source of the romaine lettuce that ill individuals were exposed to. If contaminated food products are identified in Canada, they will take the necessary steps to protect the public, including recalling the product as required. Currently, there are no Food Recall Warnings associated with this outbreak.

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