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  • dgozali 3:12 pm on November 6, 2015 Permalink | Reply
    Tags: cruise ships, , , Outbreak   

    Norovirus Outbreak on Cruise Ships 

    It’s a month before the end of the term, stress levels are rising as deadlines draw near and we count down the days before finals start. A holiday cruise seems like a perfect way to unwind and relax during your break from school or work. This was what passengers of Star Princess thought on September 19, 2015 when they boarded their 2-week long cruise to the Hawaiian Islands. Little did they know that they were about to suffer the effects of a Norovirus outbreak. On October 4th 2015, Star Princess docked in Vancouver with a total of 61 passengers who were sickened by Norovirus and displayed symptoms of acute gastroenteritis such as abdominal pain, nausea, vomiting and diarrhea. The Virus was spread through contaminated food, water and personal contact. Earlier this year, the same cruise ship experienced another Norovirus outbreak that affected a total of 135 passengers.


    The cruise ship reportedly stopped at several ports where sick passengers were taken to the hospital for further treatment. Several passengers even took a flight back from Hawaii instead of continuing the journey on the cruise. In order to prevent the further spread of the virus, several measures were implemented on the cruise ship:

    • Disinfection of hand railings, door handles and elevator buttons
    • Hand sanitizers were placed on several locations on the ship
    • Infected passengers were isolated from the rest of the passengers

    A single food source has not yet been identified for the cause of this outbreak. However, the Food and Drug Administration states that the most common sources of Norovirus include water supply on cruise ships and raw oysters, fruits and vegetables. Once the virus has infected someone, it can be easily transmitted through close contact or cross contamination. A big issue with eating contaminated food on cruise ships is that the sewage and waste produced on cruise ships is dumped 12 miles from the shore. This results in contamination of shellfish that filter-feed around the area where waste was disposed. These contaminated shellfish are then harvested and consumed by people on shore, leading to more infections or outbreaks.

    Norovirus outbreaks seem to be a recurring phenomenon on cruise ships with a total of 9 outbreaks recorded in this year alone. But why is Norovirus so notorious for causing outbreaks on cruise ships? Firstly, outbreaks on cruise ships are generally reported more quickly than outbreaks on land. Cruise ships also provide an ideal condition for the spread of Norovirus as it is an enclosed environment that increases the amount of person-to-person contact within the shared living space. The common source of food and drinks also facilitates the spread of Norovirus infection. Lastly, about a third of the passengers on cruise ships are elderly people who are more susceptible to Norovirus infections, which results in a greater incidence of infection.

    Due to the high occurrence of this issue on cruise ships, Centers for Disease Control (CDC) has created a surveillance and reporting system to prevent and reduce the risk of spreading gastrointestinal illnesses. CDC’s Vessel Sanitation Program monitors the magnitude and distribution of cases reported, helps to implement sanitation procedures, makes recommendations for control of the pathogen and conducts investigations to determine the causative agent. If the illness rate on board the cruise is 3% or more, an investigation is performed through 3 main steps:

    1) Epidemiological investigation: Measures the size of the outbreak through questionnaires, medical records and cruise ship layout.
    2) Laboratory investigation: Specimens collected from infected passengers to confirm the pathogen responsible.
    3) Environmental investigation: Uses information from the epidemiological investigation and further investigations to determine the source of infection.

    After learning about the occurrence of Norovirus outbreaks on cruise ships, would you still consider going on a cruise? Can you think of any other ways that this issue can be prevented?


    Bert, F., Scaioli, G., Gualano, M. R., Passi, S., Specchia, M. L., Cadeddu, C.. . Siliquini, R. (2014). Norovirus outbreaks on commercial cruise ships: A systematic review and new targets for the public health agenda. Food and Environmental Virology, 6(2), 67-74.

    Centers for Disease Control and Prevention. (2015). Outbreak updates for international cruise ships. Retrieved from http://www.cdc.gov/nceh/vsp/surv/gilist.htm#2015

    Centers for Disease Control and Prevention. (2015). Outbreak Investigation Overview. Retrieved from http://www.cdc.gov/nceh/vsp/surv/investigationoverview.htm
    Canadian Broadcasting Corporation News. (2015). Norovirus hits Star Princess, delays massive cruise ship in Vancouver. Retrieved from http://www.cbc.ca/news/canada/british-columbia/star-princess-cruise-norovirus-hawaii-vancouver-b-c-outbeak-1.3255632

    International Business Times. (2015). Cruise Ship Norovirus Outbreak 2015: Dozens of Star Princess Passengers Sickened By Stomach Bug. Retrieved from http://www.ibtimes.com/cruise-ship-norovirus-outbreak-2015-dozens-star-princess-passengers-sickened-stomach-2127270

    • csontani 11:20 pm on November 6, 2015 Permalink | Reply

      it’s funny cause I was actually on board another Princess cruise last August around British Isle and that ship had a Norovirus as well before my sail. I think for that case it was because of the spread from 1 infected person that boarded on the ship. I agree that there are numerous outbreaks that occur in cruise ships because they’re pretty much “isolated” in one place. Cruise ships should definitely be more strict in checking the passengers’ conditions before they board the ship. From what I see so far, they only have questionnaires that they hand out to the passengers, asking if they’ve been sick for the past couple of days/weeks, and I personally think it’s not effective cause people can just easily lie about it. So they should definitely think of a better way to monitor passengers health conditions before sailing.

    • cvalencia 4:17 pm on November 7, 2015 Permalink | Reply

      It is challenging to be on a cruise and find out that there is currently an outbreak going on… I can’t imagine having that constant worry in your mind that you or your family members might be the next ones to get ill. It just ruins the whole point of going on a cruise and having a peaceful vacation alone or with your loved ones. It’s also hard since there are little to no other options for other foods once you’re on the ship, but the ones that they serve on the buffet and cafes. I also think that it is devastating not only for the passengers but also for the cruise company, since they will now have a bad reputation because of these outbreaks. It’s great to know though that the CDC are providing guidelines to prevent future outbreaks.

    • Silvia Low 1:47 pm on November 12, 2015 Permalink | Reply

      This is so saddening to hear. I love cruise ships but I have heard of the many onboard outbreaks they often have. My understanding of how they reduce the risk of infection/contamination is by having their employees serve all the food at the buffet instead of passengers self serving. Anyway, I donot think any one cruise company should have their reputation or brand tarnished because of this because it could also be the passengers’ fault for bringing infectious illnesses onboard and the cruise companies do specifically ask all passengers if they’re sick or experiencing any symptoms prior to boarding.

    • shinnie 2:54 am on November 18, 2015 Permalink | Reply

      I believe that the newly implimented measures to prevent the spread of the virus on cruise ships will not be as effective as perceived. In fact, it may worsen the spread of the virus if the employees are led to think that hand sanitizers alone are enough to eliminate the pathogens. If sanitizers with insufficient ethanol content are used (60-65% of normal hand sanitizers is NOT enough), norovirus will not be eliminated. Studies show that hand sanitizers are useless against norovirus because the virus is non-enveloped and protected by a capsid. Statistics from the U.S. Centers for Disease Control and Prevention in winter of 2006-2007 show that “facilities in which staff used alcohol-based sanitizers were six times more likely to have an outbreak of norovirus compared to those in which staff cleaned their hands using soap and water.” The best methods to minimize norovirus outbreaks on cruise ships include minimizing food contact or food contact surfaces with bare hands and using extremy hot water and bleach to clean dishes and stainless steel surfaces. Proper hand washing should be strongly enforced on cruise ships as studies show that they are more effective in eliminating norovirus than sanitizers due to physical foce. For me personally, I will probably go on a cruise expecting to catch some kind of stomach flu.

    • Carissa Li 3:32 am on December 13, 2015 Permalink | Reply

      I was on a cruise ship this past summer too and I can relate how quickly an infection can be spread inside an enclosed environment. In my case, one of my family members caught a flu before the trip start and within 2 days, 5 other family members got infected with the flu. How quickly that was! With norovirus, I think the rate can get even faster since everyone is consuming the same food which is only one of the several routes Norovirus can take to infect people. I know that one of the surveillance cruise ships take is once they identified anyone who’s at risk, they will send them to the hospital at the next port they arrive. It is very important to make sure we all get sanitized before walking into any restaurants on the ship so as to prevent any bacteria contaminating the food as well as prevent ourself getting infected by others.

    • teewong 7:04 pm on December 14, 2015 Permalink | Reply

      I agree with this post entirely about the fact that cruise ships are more susceptible to these types of outbreaks as people are confined in a close proximity area. I was planning on booking a cruise trip this coming summer and this really made me second think my decision. I think if I were to follow through with my decision in booking a cruise trip, I would bring my own cutleries and personal towels to minimize any cross contaminations with other passengers.
      I was also wondering, in the post it didn’t mention what the cruise company did to compensate the passengers that fell ill from this infection, did they compensate these passengers at all?

    • MichelleLui 10:13 pm on December 18, 2015 Permalink | Reply

      Cruise ship can certainly provide an environment that facilitate the spread of foodborne illnesses. Good personal hygiene and sanitation program should be followed by cruise ship workers. Passengers should be prepared and take preventative measures such as immunization and follow good hygiene practices (e.g. wash hands often).

  • catherine wong 1:27 pm on October 27, 2015 Permalink | Reply
    Tags: , , Fried Rice, , , , Outbreak   

    Listeria Monocytogenes Recall in Australian Fried Rice: No Ending 

    In Australia, there was a recall on September 3, 2015 due to pre-packaged fried rice from the company JL King & Co due to Listeria monocytogenes. Both packagings of 1kg and 450g were on the recall. As of now, there is still no information about the source of contamination, how many or if there were any consumers who got sick. The best before date for this product was September 15, 2015, which was only 12 days from the date the recall was announced. (Australian Competition Consumer Commission, 2015)

    Similar to most other ready to eat foods that Listeria monocytogenes like to grow in, the shelf life is quite short and some consumers consume the ready to eat products right after purchasing. Other products such as canned foods that Clostridium botulinum can grow in, the shelf life can be up to 2 years which gives plenty of time for recalls as those consumers may not consume them immediately after purchase. The recalls for ready to eat foods such as the pre-packaged fried rice can serve the purpose of taking the food off store shelves to prevent future consumers from getting sick. However for the consumers who have consumed contaminated products before any recall notification, some of them may not even get sick due to the natural microflora present on their intestinal surfaces.

    The ones who are most susceptible to falling ill from Listeria monocytogenes are pregnant women and their unborn or newborn children, seniors and the immunocompromised. For pregnant women in the first three months of pregnancy, being sick with Listeria monocytogenes can cause a miscarriage. If the bacteria is contracted later on in the pregnancy, premature birth, stillbirth or the birth of a severely ill child may happen. The immunocompromised are much more likely to get sick but according to the Public Health Agency of Canada, people suffering from AIDS are 300 times more susceptible to being infected by Listeria monocytogenes compared to healthy individuals. (Public Health Agency of Canada, 2012)

    Listeria Monocytogenes luckily cannot grow in all ready to eat food products as long as the food product falls under one of the following three criteria according to Australia’s Food Standards (Food Standards, 2014):
    1. pH less than 4.4, no matter the water activity value
    2. Water activity less than 0.92, no matter the pH value
    3. pH less than 5.0 and water activity less than 0.94

    However, if Listeria monocytogenes is present it can survive in acid conditions and in products with low water activity for a long period of time, especially for refrigerated products. Even if the product has gone through a drying process, Listeria monocytogenes may survive. (Lawley, 2013)

    If the ready to eat food product is frozen and is consumed frozen, thawed but still eaten cold or heated before consumption then it is most likely safe from Listeria Monocytogenes. (Food Standards, 2014) If the ready to eat food product does not fit with the above criteria, then heating to an internal temperature of 74°C before eating can help in minimizing the chance of Listeria monocytogenes surviving in the food. (Public Health Agency of Canada, 2012)

    With all the conditions Listeria monocytogenes can grow or survive in ready to eat products, I feel that one of the better ways to minimize the risks of getting ill from Listeria monocytogenes is to heat ready to eat products except for frozen products before consuming. Although this might be difficult for ready to eat foods that are generally eaten at room temperature such as sandwiches.

    Are there any other methods that you think are sufficient in eliminating Listeria monocytogenes?


    Andersen, L. (2015) Listeria and Bacteriocin-Producing Starter Culture. Retrieved from http://www.foodsafetynews.com/2015/08/listeria-and-bacteriocin-producing-starter-cultures/#.Vi3XUmSrToB

    Australian Competition Consumer Commission. (2015). Product Safety Recalls Australia. Retrieved from http://www.recalls.gov.au/content/index.phtml/itemId/1076441

    Food Standards. (2014). Supporting document 1 – Guidance On the Application of Microbiological Criteria for Listeria Monocytogenes. Retrieved from

    Lawley, R. (2013). Food Safety Watch. Retrieved from http://www.foodsafetywatch.org/factsheets/listeria/

    Public Health Agency of Canada. (2012). Listeria. Retrieved from

    • ColleenChong 5:16 pm on October 27, 2015 Permalink | Reply

      I am glad you brought up that listeria monocytogenes can survive acid and low water activity environments, just as Trish has mentioned in her presentation. Although L. Monocytogenes is a heat sensitive microorganism once it contaminates processing equipment it will be a major issue because it can form biofilms, which protects the pathogen. Contamination usually occurs after post-processing as you mentioned ready to eat products. I think the general public does not need to be too concern when consuming these products. However, young children, pregnant women and immunocompromised individuals should be careful. If possible the susceptible population to try to avoid these foods in general because the serious consequences can result in listeriosis or even death.

    • Jasmine Lee 2:56 pm on October 31, 2015 Permalink | Reply

      I agree with Colleen that Listeria monocytogenes may have been introduced to this product through post-processing contamination. Potential sources may be due to unsanitary premises, unclean air ventilation, contaminated packaging and/or temperature abuse. Even though this product may pose a serious health risk for immunocompromised individuals, I find it rather surprising that there are no further details available since the date of the recall. Since Listeria monocytogenes is ubiquitous in the environment, I strongly believe multiple methods are necessary to control the presence of this pathogen. These measures may include reassessing the company’s HACCP program to reinforce proper sanitation practices, frequent microbiological monitoring and appropriate storage temperatures. A combination of rapid pathogen detection methods should be utilized because some techniques, such as PCR, may detect false positives. Alternatively, the company could look into reformulating the product to include more hurdles, such as adding antimicrobial agents and increasing lethality of the heat treatment. Applying different treatments and storing susceptible food components in separate packages (combined by the end user during consumption) may lower favorable conditions for bacterial growth. These methods may also extend the product’s shelf life.

    • RainShen 1:01 pm on November 4, 2015 Permalink | Reply

      Comparing to other pathogenic microorganisms, Listeria monocytogenes can be resistant to many stresses during the processing and before consumption which causes it becomes one of the biggest concern for consuming the ready to eat food. I agree that the best way to eliminate L. monocytogenes in the high risk ready to eat food is heating the product to at least 74C. However, the manufacturer of the ready to ear food should improve their food safety system as well which may include sanitation procedure, regular equipment checking, personnel hygiene etc, especially that L. monocytogenes can form biofilm on the surface of the equipment, so regular microbiological testing will be necessary in the ready to eat manufacturing company. Complete final products checking and testing will be needed to ensure the absence of L. monocytogenes in the ready to eat foods.

    • MarinaMoon 2:50 am on November 13, 2015 Permalink | Reply

      As Listeria monocytogenes is one of the pathogens that can withstand many hurdles during food production and storage, it should be especially cautious and have very strict regulation system regarding production that is easily susceptible to Listeria Monocytogenes contamination. However, in this article in particular, I believe that these pre-packaged fried rice would be mostly consumed by healthy individuals probably those who do not have the time to make one themselves such as college students and workers. Thus, although we should be concerned and pay close attention to be able to prevent further contamination, I don’t think it would result in severe outbreaks like some other pathogens. As elderly, pregnant women and infants are most vulnerable to contamination, I do not think this particular product would create such a disaster. Nonetheless, I think better sanitation in the production environment and more strict regulations could possibly lead to prevention of this pathogen.

    • cvalencia 5:07 pm on December 4, 2015 Permalink | Reply

      Great article on Listeria! I think that it is surprising to find this pathogen in pre-packaged, since most of the time they are found on high-risk foods such as soft cheeses and deli meats. This just goes to show that we must take extra precaution to ensure food safety, even in unexpected food items such as the case for this food item. Also, it shows that we have a long way to go in food safety to ensure that cases like these don’t happen in the future

    • Ya Gao 9:24 pm on December 15, 2015 Permalink | Reply

      It is interesting to learn the specific details about how Listeria affect vulnerable people like pregnant women and their unborn or newborn children, seniors and the immunocompromised. And it is shocking to see how AIDS change life by looking at the number “people suffering from AIDS are 300 times more susceptible to being infected by Listeria monocytogenes compared to healthy individuals”. Ready to eat food can be a great threat since people tend not to process them at home after purchasing and consume them directly. A better controlling on production, distribution and retailing of ready to eat food products is important to protect these vulnerable people from getting harm.

    • MichelleLui 10:59 pm on December 18, 2015 Permalink | Reply

      Good information on Listeria Monocytogenes. Contaminated ingredient is mostly likely the starting agent to the contamination as there has to be an introduction of Listeria Monocytogenes into the processing facility or food. There could be other contaminants such as rodents due to poor pest control program at the processing facility. Just browsing through their website, it looks like they process many items, including dairy and produce. Good sanitation standard procedures should be in place to prevent cross contamination. The firm should monitor their suppliers by testing their ingredients and packagings for pathogens or indicator organisms.

  • FeliciaYuwono 11:49 pm on October 25, 2015 Permalink | Reply
    Tags: Blue Bell, Ice Cream, , , , , Outbreak   

    Listeria Outbreak Associated with Blue Bell Ice Cream 

    Blue Bell Creameries recently did product recall for the first time in their 108 years of company’s history caused by an outbreak of Listeria monocytogenes. There were in total 10 cases in 4 states & 3 deaths affected by the outbreak. They have 3 production facilities and all of them were contaminated with Lm: one in Texas (which is the headquarters), and two auxiliary production lines in Oklahoma and Alabama. In this post, I’m focusing on what happened in the Oklahoma facility.

    The first 5 Listeriosis cases that were reported in Kansas early March 2015. They were all hospital inpatients and immunocompromised, and 3 of them actually died, which made up the total deaths for this outbreak. In late March 2015, using PFGE and Whole Genome Sequencing, Kansas Department of Health and Environment found out that the same strains of Lm found in the patients were traced back to unopened Blue Bell Creameries’ 3 oz. Institutional/Food Service Chocolate Ice Cream cups served in the hospital, which were manufactured in the Oklahoma production facility. Interestingly, this product was distributed to 23 states and only sold in schools, nursing homes, and hospitals, which mainly accomodate individuals at risk. This suggests that there were probably unreported cases of listeriosis linked to the Blue Bell Creameries’ products.


    In May 7, 2015, the FDA released findings from Blue Bell Creameries’ production facility in Oklahoma. In this report, there are 12 observations being made but I’m only going to outline several points.


    This report mentions that the Oklahoma Department of Agriculture, Food, and Forestry established a requirement of 20 CFU/mL of Lm or less in finished products of frozen dairy desserts. In March 2015, 275 CFU/mL Lm was found in the finished product half-gallon Dutch Chocolate Ice Cream, more than thirteen times the recommended levels. Now, if we assume that there is 275 CFU/mL of Lm in a 3 oz. (88mL) Institutional/Food Service Chocolate Ice Cream cup, then there is in total 24,200 CFU of Lm in one cup. However, several hospital patients fell ill after consuming the particular product, which means that the amount of Lm in that product is at least at an infectious dose of 0.1 to 10 million CFU for at risk individuals. Based on these assumptions, Lm might continue to grow under freezing temperatures, but more research needs to be done on this subject. Another possibility is that some finished products of the chocolate ice cream already had enough Lm in it to infect at risk individuals, therefore any more Lm growth would not make any impact.


    This report also mentions that the plant’s production line is not designed to prevent cross-contamination from drippings and condensate from pipes and tank lids. The lids on top of the tanks containing post-pasteurized Dutch Chocolate Ice Cream were not closed tightly, hence condensate from another product line installed horizontally right above it drips into the tanks, which makes a potential source of Lm contamination. Additionally, a worker was observed spraying the top of the lids and switching lids between other post-pasteurized Dutch Chocolate Ice Cream tanks, which may contribute to Lm cross-contamination in the tanks. The rest of the report states that lack of employee hygiene and inadequate facilities for cleaning and sanitizing equipments might be some contributing factors to the growth of Lm in their products.


    Now, if you were to be part of Blue Bell Creameries’ quality control team at the Oklahoma production facility, what would you do? What recommendations would you offer to make the production line safer?

    • wen liao 9:19 am on October 26, 2015 Permalink | Reply

      It is definitely amazing how Listeria can survive and still being infectious in made ice-creams, considering it is an environment low in temperature and water activity. As we have discussed in class before, ice-cream is considered as one of the products where there should be no growth of Listeria what’s so ever. Thus the problem here definitely are due to the ingredients. Since ice cream production are considered as low Listeria risk, people work here might pay less attention on sampling and checking on listeria load, which might be the cause of the problem. Therefore, it is important that people working in food industry pay extreme attention on what they are doing to ensure food safety.

    • YaoWang 1:39 pm on October 27, 2015 Permalink | Reply

      We all know that Listeria is a main concern in ready to eat meat products, but it’s amazing to know that it can be a problem even in ice cream. Normally, since ice cream provides low temperature and low water activity, we assume there shouldn’t be Listeria present. I’m very curious about how listeria can survive and may even grow under such environment. But this recall reminds us that even though the food is of less possibility of certain microbial contamination, the manufacture must still follow proper handling techniques to avoid potential cross contamination.

    • amreenj 7:18 pm on October 28, 2015 Permalink | Reply

      Wow! As we have previously learned, ice cream is considered a Category 2B food, which is a ready to eat foods in which Listeria monocytogenes cannot grow. So the occurrence of Lm. in ice cream is surprising. Im interested to see if they can actually trace the source of the Lm. and report back their findings. The worse part is that it was given to individuals whose immunity is low (ie. high risk groups- longer term care facilities, hospitals) and thus the impact could have been so much worse. Having preparing sanitation and handling protocols is imperative to recurring the risk of food borne illnesses. As we can we that failing to do so can lead to contamination in even the most unlikely of places/foods!

    • mustafa akhtar 10:18 am on October 29, 2015 Permalink | Reply

      I am so surprised that they ONLY distributed this product to schools, nursing homes, and such. I wonder if any research was put into developing the product at all. If not, then atleast the product shouldn’t have been sent to places where immunocompromised people reside.

    • Susanna Ko 4:55 pm on October 29, 2015 Permalink | Reply

      I think it shows that people must be diligent when deciding on the food menu for certain populations such as elderly or immunocompromised. Also, it’s surprising that the company survived so far without failing an inspection. Was it because it was categorized as a low-risk food, meaning that it is inspected less frequently? Also, how many spontaneous abortions occurred from pregnant women consuming this product because they wanted to enjoy a special treat? It’s really unfortunate.

    • Stephanie Chen 6:00 pm on November 19, 2015 Permalink | Reply

      It is really quite sad that even a delicious treat such as ice cream can harbor foodborne pathogens, and with a company that must have had good reputation for so many decades. Bluebell also explained that the reason they did not test their ice cream after positive tests of Listeria in their plant in previous years was because Listeria was found on non-food surfaces that did not come in contact with ice cream products. It was also not required at the time to report Listeria findings to the FDA. This shows that practices in the industry need to be routinely evaluated and food safety regulations should be strictly enforced.

    • meggyli 10:11 pm on November 27, 2015 Permalink | Reply

      Another interesting class-related blog! We learned in class that ice cream belongs in a category 2B food where the chances of Listeria growth/contamination is really rare. Similar to the above caramel apple blog, this just goes to show that we can never be too careful. It always causes the most damage to our health and economy when it’s the most unexpected food that contracts a pathogen. Who would have thought that something like ice cream which inhibits most microbial growth due to its cold storage temperature could cause something as severe as stillbirths & spontaneous abortions.

    • Mandy Tam 9:02 pm on December 1, 2015 Permalink | Reply

      I think a lot of time when people think of outbreak in related to Listeria Monocytogenes are related to ready to eat meat or deli product. I think this article provides a great example that Listeria growth could happen in other foods as well.
      North America very emphasis in HACCP and GMP in food plants but there are still many problems. I think what will help food plant to improve food safety in the future is to have a database approved by government agency where companies can share and excess information in regard of good plant design and HACCP program information in all food type. Therefore, it avoids problems caused by bad equipment design or inexperience HACCP team.
      Anyhow, great article and it provides a lot of insight in term of Listeria Monocutogenes!

    • cheryl lau 3:19 pm on December 4, 2015 Permalink | Reply

      Very interesting article! I am also surprised that this is the first time that the company has recalled their products due to Listeria monocytogenes contamination from the conditions mentioned in the FDA report. Condensed water from pipes in food manufacturing is often a problem if not dealt with. These problems usually present over time, I am surprised that the plant allowed production to continue. Perhaps the quality control personnel should ensure that the workers realize the risk involved from contamination due to irregular working conditions. The workers could then report to the supervisor when the equipment is not functioning at the optimum level to prevent these outbreaks from happening.

  • Michelle Ebtia 7:27 pm on October 16, 2015 Permalink | Reply
    Tags: , , Leafy Green Vegetables, Outbreak, PHAC Outbreak Timeline   

    No Surprises in E. coli Outbreaks of Eastern and Central Canada: The Usual Food-Source, and PHAC’s Anticipated Race against Time! 


    The Public Health Agency of Canada (PHAC) , the institute in charge of responding to public health emergencies and infectious disease outbreaks, published a final update on the E. coli outbreak that occurred between July 6 and September 4, 2015, in Alberta, Ontario, Quebec and Nova Scotia. Of the 29 cases reported, seven were hospitalized.

    According to PHAC, investigators identified E. coli O157 to be responsible for this outbreak, “with the use of enhanced techniques”, that enabled them to rule out 2 other reported cases with similar gastrointestinal symptoms, as not being related to the outbreak strain. The food-source associated with the outbreak has not been identified yet, but further investigations are underway.

    This is the second E. coli outbreak of 2015 in Eastern Canada, with the first occurring between March 13 and March 31 in Alberta, Saskatchewan, Ontario, and Newfoundland and Labrador; all the 13 cases that were reported had a matching genetic fingerprint of E. coli O157:H7.
    According to PHAC report, exposure to contaminated leafy greens (including all varieties of lettuces, in addition to other green leafy vegetables such as kale, spinach, arugula, or chard) was identified as the possible source of the outbreak. However, CFIA could not identify a specific food product as the single source of the pathogen, which illustrates the challenges associated with food-source attribution in outbreaks.

    Escherichia coli O157:H7, a Shiga toxin–producing E. coli (STEC) is the strain most commonly associated with outbreaks of bacterial gastrointestinal disease in the North America. The subpopulation most severely affected by the outbreaks have historically been young children, and the elderly, whereas in the latest Canadian outbreak discussed in this report, the majority of patients were young males (average age of 23); however, the report does not disclose the age distribution of the patients who were hospitalized due to the severity of their condition.

    The most common routs of transmission of E. coli pathogen, leading to outbreaks are generally identified to be contaminated food, water (drinking, irrigation or swimming), and environment, as well as person-to person and animal-to-person contact (Turabelidze et al. 2013).

    Analysis of outbreak data suggest that foods most frequently implicated in outbreaks in North America are ground beef, leafy green vegetables, and unpasteurized dairy products, as well as sprouts, unpasteurized apple cider, melons and other fruits, and salami (Neil et al. 2009). Therefore, the suggested association of the earlier outbreak to leafy green vegetables, is in line with the characteristics of outbreak food-sources in general.

    guiltyNumerous studies have specifically examined the survival and growth of E. coli on leafy vegetables. For instance, Parker et al. (2011) demonstrated E. coli’s “ability to multiply in the phyllosphere of whole lettuce plants” on shredded and intact harvested lettuce leaves, due to an up-regulation of genes involved in oxidative and osmotic stress, which also make the bacteria more resistant to antimicrobials commonly used in the fresh-cut produce industry. Therefore, the food industry needs to implement more effective strategies in handling raw vegetables.

    Examining the timeline of PHAC’s report on E. coli outbreaks, reveals that in both occasions, it took the agency over two months from the time of the first reported case, to come to a final conclusion about the strain and possible food source. A similar timeline can be observed in E. coli outbreaks from previous years as well (2012 and 2013). The use of new and improved methods, such as Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF)-Based Peptide Mass Fingerprinting, as suggested by Chui et al.(2015) can contribute to a more rapid identification and fingerprinting of the pathogen, which can in turn, reduce the burden of outbreaks by early targeting of the attributed food source.

    How can we, as consumers, prevent outbreaks from happening? How do you evaluate the effectiveness of communication methods, and timeliness of response to outbreaks by PHAC?


    Works Cited:

    Neil, K. P., Biggerstaff, G., MacDonald, J. K., Trees, E., Medus, C., Musser, K. A., … & Sotir, M. J. (2012). A novel vehicle for transmission of Escherichia coli O157: H7 to humans: multistate outbreak of E. coli O157: H7 infections associated with consumption of ready-to-bake commercial prepackaged cookie dough—United States, 2009. Clinical infectious diseases54(4), 511-518.

    Parker, C. T., Kyle, J. L., Huynh, S., Carter, M. Q., Brandl, M. T., & Mandrell, R. E. (2012). Distinct transcriptional profiles and phenotypes exhibited by Escherichia coli O157: H7 isolates related to the 2006 spinach-associated outbreak. Applied and environmental microbiology78(2), 455-463.

    Turabelidze, G., Lawrence, S. J., Gao, H., Sodergren, E., Weinstock, G. M., Abubucker, S., … & Tarr, P. I. (2013). Precise dissection of an Escherichia coli O157: H7 outbreak by single nucleotide polymorphism analysis. Journal of clinical microbiology51(12), 3950-3954.

    • Jasmine Lee 8:01 pm on October 17, 2015 Permalink | Reply

      In my opinion, I believe that our nation’s food safety system has come a long way to reduce the outbreaks of E. coli O157:H7, bringing the incidence rate per 100,000 people down from 3.8 to 1.4 in nine years (PHAC’s graph from lecture notes). Regardless, we can and will continue to do better. I agree that two months is a considerably long time for PHAC to identify the causative agent and contaminated food source. However, this may be due to many factors that hinder the efficiency of the investigation, such as under-reporting, method availability and instrument sensitivity. Under-reporting from patients’ reluctance to visit the doctor may be the ‘rate limiting step’ in identifying the outbreak. I strongly believe more emphasis could be placed on educating the public about foodborne illness. While the food industry is doing its best to minimize the risk of transmissible foodborne pathogens, consumers need to be better informed about practicing proper hygiene and reporting their symptoms to their healthcare practitioners so that it would be on record. PHAC should work closely with the provincial health agencies, e.g. HealthLink BC, to deliver outbreak information to the public through posters, community workshops, public service announcements and social media. Consumers should also ensure that their produce are washed thoroughly prior to consumption, stored under refrigeration and discarded if the quality is doubtful. Outbreaks are inevitable unless policymakers, food producers and consumers all do their part.

      • Michelle Ebtia 9:52 am on October 27, 2015 Permalink | Reply

        Hi Jasmine,
        Thanks for your very thoughtful comment. I specially agree with your suggested methods of reaching the public through the use of community workshops and social media, and think they have a higher potential in raising awareness than what is being used now!

    • flyingsquirrel 8:41 pm on October 18, 2015 Permalink | Reply

      This is most concerning because the consumption of whole/raw leafy green vegetables is on the rise as people become more aware of health and weight balance. Common ingredients such as kale, lettuces, arugula, and spinach are often found in salad mixes sold to the masses on a daily basis. I agree with Jasmine that public education about how to handle foods to prevent illness is definitely one of the best ways to prevent outbreaks. Aside with working with provincial health agencies,I think a point of target that PHAC should address soon with provincial sectors, is how small-scale organic farms will be handled in terms of safety inspections, practices, and certificates. Although they are small compared to the big corp farms,they are essential in the Canadian market as popularity is increasing for pro-local and organic foods. Small-scale organic farmers do not completely follow the rigors of inspection due to financial issues and this topic is still being debated. How can all producers follow a standard guideline in inspection and safety of foods without financial restrictions?

      • Michelle Ebtia 9:57 am on October 27, 2015 Permalink | Reply

        Thanks for your interesting comment! That is definitely a concern which needs to be addressed, considering on a greater scheme, the cost of illness for these outbreaks may well outweigh the expenses required for thorough testing and ensuring the safety of these food items.

    • meggyli 9:22 pm on October 25, 2015 Permalink | Reply

      Very interesting article! We often associate E. coli with under-cooked beef or meat products but many people seem to forget about the leafy greens component that’s also a major part of our diet. In my opinion, as food practitioners we should also emphasize the importance of proper handling and cleaning of ready-to-eat or fresh foods in addition to the potentially hazardous or high-risk foods because not only are leafy greens a source of E. coli they are prone to causing Salmonella spp. as well! From the course notes we also saw that in the United States produce cause the most foodborne-associated illnesses, whereas meat and poultry causes the most foodborne associated deaths.

      • Michelle Ebtia 10:05 am on October 27, 2015 Permalink | Reply

        Hi Meggy,
        I agree that meat and poultry seem to be regarded by the general public as the major source of contamination with food-borne pathogens, which calls for a more effective strategy to be adopted in order to raise awareness about risks associated with produce! I think as Jasmine pointed out, community workshops and social media might be effective tools in educating the public about the topic.

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