7 Customers Showed Symptoms of Scombroid Fish Poisoning after Eating in a Sydney Café

Posted on November 20, 2015 by | 9 comments

Seven people fell ill and showed symptoms of scombroid poisoning after eating from the same food outlet in the Sydney CBD, Soul Origin café, in late February 2015. The tuna, which was served in sandwiches at the café, was suspected to have caused scombroid poisoning.

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source: http://www.abc.net.au/news/2015-02-26/scombroid-fish-poisoning-linked-to-sydney-cafe-tuna/6263120

The New South Wales (NSW) Food Authority in Australia investigated that the canned product “John Bull Tuna Chunky Style in Sunflower Oil”, which Soul Origin café used, is a product of Thailand and imported into Australia by a Victorian company. This minor brand was used predominately in catering; it was not generally available to the public. The outbreak was not widespread and all affected product was removed from the market immediately.

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source: http://ausfoodnews.com.au/2015/03/11/canned-tuna-food-safety-scare-linked-to-thai-factory.html

The NSW Food Authority tested the leftover tuna salad at the café to have 3950 micrograms of histamine per kilogram of tuna. The test result was well above the acceptable limit of 200 micrograms histamine per kilogram of fish.

Scombroid poisoning is an allergic-type reaction to elevated levels of histamine in fish. It occurs when an enzyme produced by naturally occurring bacteria in certain fish species (including tuna, sardines, mackerel, swordfish, and marlin) convert histidine in the fish to histamine. Elevated levels of histamine amino acids in the fish produce cause the food poisoning. The temperature abuse of the fish produce at the catching or processing stage is usually the cause of the scombroid poisoning. The presence of high level of histamine in fish shows that decomposition of fish produce has occurred. The histamine toxin is not inactivated by ordinary cooking methods, and the contaminated fish will not necessarily appear spoiled.

Symptoms of histamine poisoning occur quickly, usually within 30 minutes or a few hours upon ingestion of contaminated fish. The symptoms typically last for a few hours. However, in some cases, they can last for several days. Common symptoms of histamine poisoning including peppery or metallic taste sensation, tingling of mouth and lips, skin rash or itchy skin, headaches, and dizziness; nausea, vomiting and diarrhea may also occur in some cases. People with scombroid poisoning may be treated with antihistamines. Scombroid poisoning is rarely fatal, but it was thought to have killed a Australian mother and daughter, Noelene and Yvana Bischoff, while they were on vacation in Bali in January 2014. However, the case is extremely rare.

Here is the news article on the tragedy happened in Bali:
http://www.news.com.au/national/bali-deaths-of-noelene-and-yvana-bischoff-from-fish-poisoning-impossible-to-predict/story-e6frfkp9-1226818860731

Histamine poisoning is rare, and there have been less than 10 outbreaks of histamine poisoning with 187 people diagnosed with the poisoning in Australia over the past 10 years.

Since histamine is not destroyed by heat treatments, buying seafood from reputable sources to ensure the product is kept refrigerated when it is being transported and stored becomes the best way to protect us against scombroid poisoning.

News sources & Reference:
Australian Broadcasting Corporation, 2015. Scombroid Fish Poisoning Linked to Sydney Café after Four Customers Fall Ill. Retrieved from http://www.abc.net.au/news/2015-02-26/scombroid-fish-poisoning-linked-to-sydney-cafe-tuna/6263120

Australian Food News, 2015. Canned Tuna Food Safety Scare Linked to Thai Factory. Retrieved from http://ausfoodnews.com.au/2015/03/11/canned-tuna-food-safety-scare-linked-to-thai-factory.html

Canadian Food Inspection Agency, 2012. Food Safety Facts on Scombroid Poisoning. Retrieved from http://www.inspection.gc.ca/food/information-for-consumers/fact-sheets/food-poisoning/scombroid/eng/1332280657698/1332280735024

Daily Mail Online, 2014. Australian Mother and Daughter Who Died in Bali Hotel Room Victims of Rare Fish Poison. Retrieved from http://www.dailymail.co.uk/news/article-2551853/Australian-mother-daughter-died-Bali-hotel-room-victims-RARE-fish-poison-combined-asthma.html

Food Standards Australia New Zealand, 2015. Histamine (Scombroid) Fish Poisoning. Retrieved from http://www.foodstandards.gov.au/consumer/safety/Pages/Histamine-(Scombroid)-fish-poisoning.aspx

New South Wales Food Authority, 2015. Update: NSW Food Authority Investigation into Scombroid at Sydney Café. Retrieved from http://www.foodauthority.nsw.gov.au/news/media-releases/mr-26-Feb-15-scobroid-sydney-cafe#.Vk_Ii0ujZ4U

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Another multistate Listeria outbreak: this time from contaminated soft cheese

Posted on November 20, 2015 by | 4 comments

karounrecallcheese

Recalled soft cheese products. Source: CDC

An outbreak regarding soft cheese contaminated with Listeria monocytogenes finally arrived to a conclusion after five years of investigation. Starting in June 2010, thirty cases of listeriosis caused by the consumption of a specific type of cheese happened throughout the United States. Most of the cases were reported in California, but there was also a great number of cases happening specially in the eastern portion of the country, occurring in nine other states. According to the Center for Disease Control and Prevention, aside from California, there were also cases in Colorado, Illinois, Massachusetts, Michigan, New York, Ohio, Tennessee and Washington, and overall the outbreak resulted in 28 hospitalizations and 3 deaths, two in California and one in Ohio. Five illnesses were pregnancy-related, and one resulted in miscarriage.

The Center for Disease Control and Prevention was able to link all those cases together using whole genome sequencing, which is a molecular subtyping method that is recently becoming more used by publich health authorities to identify foodborne pathogens. This method relies on sequencing the nucleic acid of the target microorganism and detecting the differences in that nucleic acid sequence.

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People infected with the outbreak strains of Listeria monocytogenes by contaminated soft cheese. Source: CDC

Whole genome sequencing, as its name suggests, is a method that provides a nearly complete sequencing of bacterial nucleic acids, and that is what makes it a very accurate method, since it becomes much easier to compare and differentiate between serotypes of a specific bacteria. The first generation was not very user-friendly for the detection of foodborne illnesses outbreaks, as it was a very time-consuming, labor-intensive and expensive method. However, nowadays the development and improvement of next-generation sequencing methods have made these tools more available and affordable for laboratories, making it easier to use them routinely and ensuring not only precise, but also fast results, and at a reasonable cost. These methods are rapidly becoming more accepted by public health and regulatory agencies, and in the next few years they will probably replace the most commonly used method currently, which is pulsed-field gel electrophoresis (PFGE). Compared to the latter, whole genome sequencing methods have a higher discriminatory power for outbreak detection and allow for the sequencing of different pathogens in the same batch.

The whole genome sequencing methods provide better discrimination between the subtypes, and therefore it can distinguish isolates that have a similar or equal PFGE profile, therefore improving the detection of a possible outbreak. This is what happened in this case, as the public health agencies could not properly connect all the cases that happened throughout the country with only one pathogen for over five years, and the whole genome sequencing showed that five rare DNA fingerprints of Listeria monocytogenes were related, connecting serotypes identified in this last August with serotypes found in the cases from around five years ago.

The types of cheese involved in this outbreak were soft cheese, including Middle Eastern, Eastern European, Mediterranean and Mexican-style cheeses. The contaminated products likely responsible for the outbreak were from the brands Karoun, Arz, Gopi, Queso Del Valle, Central Valley Creamery, and Yanni, all of which were manufactured by Karoun Dairies, Inc. This company announced a voluntary recall of the products from those brands and stopped the production of other cheese products that might be contaminated with Listeria on September 16, 2015.

Even though the incident was not very recent, a lot of restaurants and people may still have cheese products from those brands as the recall happened this year, and they are advised not to serve or consume these products as they may be contaminated with Listeria monocytogenes. It is very important that people don’t consume them, as listeriosis is a very severe disease, specially for children, the elderly and immunosuppressed population.

References:
Centers for Disease Control and Prevention. (2015). Multistate Outbreak of Listeriosis Linked to Soft Cheeses Distributed by Karoun Dairies, Inc. (Final Update). Retrieved from: http://www.cdc.gov/listeria/outbreaks/soft-cheeses-09-15/index.html

Zuraw, L. (2015). Final Update: 3 Deaths, 30 Illnesses in Outbreak Linked to Soft Cheese. Retrieved from: http://www.foodsafetynews.com/2015/10/1-death-24-illnesses-in-listeria-outbreak-linked-to-soft-cheese/

Wiedmann, M. (2015). Use of Whole-Genome Sequencing in Food Safety. Retrieved from: http://www.foodsafetymagazine.com/magazine-archive1/junejuly-2015/use-of-whole-genome-sequencing-in-food-safety/

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Listeria Seizes the Oppor-tuna-ty! Denmark investigates outbreak linked to smoked fish products

Posted on November 20, 2015 by | 6 comments

scrambled-eggs-smoked-salmon

August 2015. Four people sickened by Listeria in fish products linked to fish company, Hjerting Laks, in Denmark. Earlier in May, five cases of Listeria with two deaths were detected in Denmark. Two out of the five were of the same strain of Listeria that caused 40 cases and 16 deaths in deli meats in 2014. Although the current outbreak is not linked to the one last year, one of the five in May was traced back to Hjerting Laks.

Unique culprit. While all tested samples did not reveal to have Listeria above the accepted limit, the Danish Veterinary and Food Administration (DVFA) found that Listeria isolates from the patients and samples taken from the company’s production area, equipment, and official food samples gave a DNA match after whole genome sequencing. The Listeria monocytogenes ST6 sequence pattern specific to this outbreak has not been detected in samples from other sources.

Suspect: smoked fish. The source of infection in exact products has not been confirmed by the DVFA, but smoked salmon was suspected due to patients’ common consumption prior to illness. An outbreak of Listeria connected to Hjerting Laks was related to smoked halibut in November 2014, after which changes in the production processes were made. Hjerting Laks states that the bacteria from the current outbreak may have originated from raw materials supplied by sub-contractor.

“We have ordered the company to change its routines with regards to production and own-check scheme,” says Annette Perge, head of unit in the DVFA. “Tightened supervision” has been placed on the company, and DVFA has advised customers to discard related fish products or return them to the place of purchase.

Listeria monocytogenes. A gram positive, facultative anaerobic bacterial species capable of causing infections that may lead to symptoms of fever, muscle aches, and diarrhea. Populations including those with compromised immune responses due to age, pregnancy, and disease are typically at higher risk for listeriosis, with possible deadly effects on fetus and newborn infants. The primary route of transmission for this pathogen is through food, and especially in ready-to-eat foods that support bacterial growth of L. monocytogenes.

But smoked fish? Yes, smoked fish. Smoked seafood including salmon, trout, tuna, oysters, etc., are manufactured in two primary forms: cold-smoked and hot-smoked product. Typical temperatures used for cold-smoking (22-28°C) are inadequate to inactivate L. monocytogenes, but levels of the pathogen present on raw salted fish are usually reduced by 90-99% during the cold-smoking steps of salting, drying, and smoking. Hot-smoking involves initial drying at 30-40°C, then smoking at 60-70°C followed by a second drying procedure. However, products may be contaminated after both cold and heat treatment in the processing environment while products are sliced and vacuum packaged. It also doesn’t help that Listeria can grow at refrigeration temperatures and is relative resistant to heating, acidic and high salt environments, as well as other inhibitory compounds used on foodborne microorganisms.

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See diagram. Production process has multiple opportunities for contamination. (Where else do you see places for Listeria to sneak in?)

 

Recommendations for persons at high risk (weakened immune system) from the CDC:

  • Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish (e.g. casserole)
  • Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, and mackerel, is most often labeled as “nova-style,” “lox,” “kippered,” “smoked,” or “jerky.” (These are typically found in the refrigerator section or sold at seafood and deli counters in grocery stores)
  • Canned and shelf stable tuna, salmon, and other fish products are safe to eat

Reduce risk for listeriosis from smoked fish by… Using ready-to-eat foods as soon as possible (product’s shelf-life shortens upon opening the packing). And remember to practice good hygiene in the kitchen!

 

News sources:

Listeria traced to Hjerting Laks despite fish products passing tests. (Aug 2015). http://www.foodqualitynews.com/Food-Outbreaks/Denmark-investigates-four-Listeria-cases-linked-to-fish-producer

Denmark investigates new Listeria outbreak. (May 2015). http://www.foodqualitynews.com/Food-Outbreaks/Listeria-sickens-five-and-a-factor-in-two-deaths

References:

Joint FAO/WHO Activities on Risk Assessment of Microbiological Hazards in Foods. Case Study: Listeria monocytogenes in Smoked Fish (including digram). Retrieved from http://www.fao.org/fileadmin/templates/agns/pdf/jemra/Listeria.pdf

Report of the FAO Expert Consultation on the Trade Impact of Listeria in Fish. Retrieved from http://www.fao.org/docrep/003/x3018e/x3018e05.htm

Center for Disease Control and Prevention. Whole genome sequencing. Retrieved from http://www.cdc.gov/listeria/pdf/whole-genome-sequencing-and-listeria-508c.pdf

Center for Disease Control and Prevention. Tips for preventing Listeria poisoning. Retrieved from http://www.cdc.gov/ncezid/dfwed/pdfs/tips-preventing-listeria-508c.pdf

Image retrieved from http://www.rivertea.com/blog/7-healthy-breakfast-recipes-for-every-day-of-the-week/

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Posted in Week 7

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Salmonella: in Frozen Raw Tuna?

Posted on November 19, 2015 by | 14 comments

map-07-21-2015-300x201

Q: What’s the big problem here with Salmonella?

A: A Salmonella seafood outbreak that hit United States has caused 62 sick across 11 states as of July 20, 2015. US CDC reported that there were 11 cases of hospitalization and no case of deaths. 97% of the infected population recalled the consumption of sushi with raw tuna a week before becoming ill. Results from laboratory and epidemiological investigations indicated that these people were likely infected with Salmonella Paratyphi B variant L(+) tartrate(+). Raw tuna processed in Indonesia by Osamu Corporation were confirmed responsible for 18 cases in California and some cases of infections in Minnesota.

As a result, on July 21, 2015 Osamu Corporation called for a voluntary recall of two categories of items, frozen tuna and yellowfin tuna, processed in their Indonesian plant.

 

Q: Isn’t Salmonella usually found in eggs and poultry?

A: As known to the general population, Salmonella is often associated with foodborne illness due to its growth in poultry and egg products, as well as produce and complex foods. An interesting fact is that Salmonella is also a common pathogen found in seafood. Together with Shigella, these two pathogens constitute up to 10% of the reported foodborne illnesses in United States. Fish, shrimp, oysters and clam are food vehicles most often associated with seafood outbreaks.

 

Want to know more? Here is a relevant video about Salmonella in seafood (published 3 years ago):

 

Q: “Who” is Salmonella? Where is it from? How is it identified?

A: Salmonella is a gram negative, rod shape, facultative anaerobic, non lactose fermenting bacillus with as much as 2500 serotypes identified. Transmission routes can include food-borne and water-borne, person to person and contact with animals. According to US FDA, Salmonella can be found in seafood that is intended for minimal processing and cooking.

The source of this contamination can be traced back to the acquisition of the bacteria in polluted waters. Therefore to prevent outbreaks, current measures are carried out in harvesting waters before the final harvest. Another route of contamination can be traced to the processing and storage of the seafood.

Laboratory test of stool samples from infected patients are used for diagnosis of salmonellosis. Further tests are required to discover the subtype of Salmonella responsible for the illness.

 

Q: Yikes! What are the symptoms of salmonellosis?

A: Salmonellosis, an infection caused by Salmonella, can cause acute gastroenteritis, accompanied by symptoms such as diarrhea, fever, and abdominal cramps from 6 to 72 hours. Headaches, nausea and vomiting in individuals may also be visible. However these symptoms usually disappear in 4 to 7 days, when many people recover. During this period, large volume of liquid is required to replace lost fluid from diarrhea. Severe manifestations include enteric fever, urinary tract infections, bacteremia and severe focal infections. Up to 10% of patients with typhoid fever can develop serious complications.

In the circumstance of bacteremia, Salmonella can spread from intestines to blood eventually causing severe illnesses leading to death. Antibiotics may be applied to cure the disease, however antibiotic resistance is a perplex issue. Chronic pain in joints, urination pain and irritation of eyes can be some long term complications. In severe cases, chronic arthritis is observed in these patients.

 

Q: Who is more likely to be infected? Are there any patterns that can be observed?

A: Within the infected population, pregnant women, immuno-compromised individuals, young children (<5) and seniors (>65) are most likely at risk for developing severe disease. Consequently these individuals are advised to avoid consumption of raw finfish and shellfish. Patterns have been recorded regarding age and season: infants and elderly are on top of the list for being most vulnerable to salmonellosis; those infected individuals who consume contaminated food during the summer and early fall seasons are likely to contribute to the infection numbers.

 

Q: What about… specifically Salmonella Paratyphi B variant L(+) tartrate(+)?

A: Salmonella Paratyphi B variant L(+) tartrate(+) (formerly Salmonella Java) belongs to the subspecies of Salmonella enterica and is known to cause non-typhoid salmonellosis. In contrast, Salmonella Paratyphi B variant L(+) tartrate(-) causes paratyphoid fever.

 

Tuna-sushi

Q: How should we “wrestle” with the pathogen especially in seafood?

A: Besides usual ways of avoiding foodborne illnesses, effective methods of preventing foodborne illness in specifically seafood, as suggested by US FDA, include:

  1. Washing hands, utensils and cooking surfaces
  2. Cooking seafood for 15 seconds at minimum of 145oF
  3. Avoid cross contamination by separating raw and cooked seafood
  4. Storing seafood below 40oF in the refrigerator or below 0oF in the freezer

 

And finally… Questions for you!

  1. What is a possible reason for Salmonella to be able to grow in frozen raw tuna?
  2. What are some possibilities that the infection cases can occur over 11 states (possible routes)?

 

Salmonella in raw tuna articles:

http://www.foodpoisonjournal.com/foodborne-illness-outbreaks/salmonella-sushi-outbreak-update-62-sick-in-11-states/#.VkooIK6rSfV

http://www.foodsafetynews.com/2015/04/25-salmonella-cases-possibly-linked-to-raw-tuna-consumed-in-southern-california/#.VkoeCq6rSfU

http://bigmedicine.ca/wordpress/tag/salmonella-paratyphi-b-variant-l-tartrate/#sthash.VN7LcdMj.dpbs

 

FYI… Check it out! (References:)

Epidemiology of Seafood-associated infections in United States:

http://cmr.asm.org/content/23/2/399.full

Facts on Seafood safety:

http://seafoodhealthfacts.org/seafood_safety/practitioners/microbes.php

Salmonella Q&A:

http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/foodborne-illness-and-disease/salmonella-questions-and-answers/

WHO document on Typhoid Fever:

http://www.who.int/rpc/TFGuideWHO.pdf

WHO document on Non-typhoid fever:

http://www.who.int/mediacentre/factsheets/fs139/en/

Government of Canada guidelines:

http://healthycanadians.gc.ca/eating-nutrition/risks-recalls-rappels-risques/poisoning-intoxication/poisoning-intoxication/salmonella-salmonelle-eng.php

Paratyphoid fever:

http://www.health.alberta.ca/documents/Guidelines-Paratyphoid-Fever-2014.pdf

Youtube video on this case:

https://www.youtube.com/watch?v=GZf7mk7bibY

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Week 7–Something Fishy about the Seafood Industry: Watch out on What You Eat!

Posted on November 16, 2015 by | 13 comments

cooked-fish-clip-art-696751
Recently, the Food and Drug Administration (FDA) of the United States has been alerted that detectable amount of formaldehyde (which is known to the public as “formalin”) contaminated frozen fish was found at national grocery retailers in Greensboro, North Carolina. Usually, some fish species naturally contain a trace level of formaldehyde as one product of their metabolites. However, this metabolic product is produced in such small amount that it is considered undetectable. The laboratory confirmed formaldehyde positive result of these frozen fish indicated that formaldehyde has been intentionally added. It is later discovered that these formaldehyde contaminated fish products were originated from China and Vietnam.

Formaldehyde, which is not commonly used in North America, is rather routinely exploited as a perseverative for fish in some Asian countries. Research (Sotelo et al., 1995) has shown that formaldehyde can prevent fish protein denaturation during frozen storage, keeping the flesh fresh for a much longer time. This is ideal for long distance shipping and trading—for instance, exporting fish and fish products from Asia to North America.

In addition, this is not the first and only time that fish and fish products that originate in China and Vietnam are formaldehyde contaminated. In 2013, however, formaldehyde was also identified from frozen fish products in grocery stores in Raleigh, NC, according to Food Safety News (2013). These formaldehyde contaminated fish also originated from China and Vietnam, and they constitute up to 25% of the entire seafood imports from these two countries.

Moreover, besides China and Vietnam, other Asian countries also have issues with formaldehyde application to seafood and fishery industry. Bangladesh (Rahman et al., 2015) for example, has long been suffering from formaldehyde adulteration on their fish products. According to the World Health Organization (WHO) (Liteplo, 2002), fish products have naturally occurring formaldehyde found in their flesh that ranges from 1 to 20mg/kg fish. However, the mean formaldehyde concentration in locally harvested fish in Bangladesh was 118.6mg/kg fish, about 6 times higher then the suggested value by WHO. This data strongly indicates that formaldehyde was intentionally added to the fishes, as unprocessed fish would not contain formaldehyde in such high concentration.

The health risks associated with formaldehyde exposure are complicated. According to the National Cancer Institute (NCI, 2010) short-term health effects from formaldehyde exposure include watery eyes, nausea, skin irritation, and etc. Long-term exposure to formaldehyde can significantly increase the chance of getting cancer. Especially, it can increase the risks of acquiring leukemia and brain tumor.

Although not as frequently reported as other food safety related concerns, formaldehyde adulteration in fish and fish products is still a potential threat to public health. Its occurrence might be relatively rare, but its complication can be devastating. Especially in Asian countries, where the population density is high but the economical development is low, limited public resources can make the treatment of formaldehyde exposure hard. Therefore, it is essential that the governments of corresponding countries take serious responsibility, carefully monitor their food production systems, making sure no unqualified products slip through.

References:
• Sotelo, C., Pineiro, C., & Perezmartin, R. (1995). denaturation of fish proteins during frozen storage – role of formaldehyde. Zeitschrift Fur Lebensmittel-Untersuchung Und-Forschung, 200(1), 14-23.
• Imports and Exports: How Safe is Seafood From Foreign Sources? | Food Safety News. (2013, November 10). Retrieved November 15, 2015, from http://www.foodsafetynews.com/2013/11/imports-and-exports-how-safe-is-seafood-from-foreign-sources/#.ViQNtyBViko
• Rahman, S., Majumder, M., Ahasan, R., Ahmed, S., Das, P., & Rahman, N. (2015). The extent and magnitude of formalin adulteration in fish sold in domestic markets of Bangladesh: A literature review. International Journal of Consumer Studies. doi:10.1111/ijcs.12238
• International Program on Chemical Safety, Liteplo, R. G., & W. H. Organization, (2006). Concise international chemical assessment document, number 40: Formaldehyde World Health Organization (WHO).
• Formaldehyde and Cancer Risk. (2011, June 10). Retrieved November 15, 2015, from http://www.cancer.gov/about-cancer/causes-prevention/risk/substances/formaldehyde/formaldehyde-fact-sheet

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Three Cases of “Flesh eating” Bacterial Infections in…

Three Cases of “Flesh-eating”

Bacterial Infections in Hong

Kong

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Three cases of necrotizing fasciitis— an infection caused by bacteria that destroys skin, fat, and the tissue covering the muscles in a short period of time—have been reported in Hong Kong during the month of July in 2015. Similar sporadic cases have also been reported in April and August of 2015 in Hong Kong. The affected include: an 82-year-old man and 78-year-old woman with underlying chronic illnesses and a 59-year-old man with good past health.

Source: http://outbreaknewstoday.com/hong-kong-reports-3-necrotizing-fasciitis-cases-in-july-vibrio-vulnificus-the-culprit-51333/

The causative agent is a rare but deadly pathogen, Vibrio vulnificus and its name literally translates to “causing wounds” in Latin. V. vulnificus is one of the three major species of Vibrio, with the other two being V. cholera and V. parahaemolyticus both of which are pathogens of humans.

Vibrio vulnificus

V. vulnificus is a Gram-negative, lactose-fermenting, opportunistic (similar to L. monocytogenes), and motile curved bacterium commonly found in marine and estuarine environments. It is a moderate halophile (requires salt for growth) and is frequently isolated from oysters, clams, crabs, and other shellfish in warm coastal waters. It is responsible for causing 95 percent of all seafood-related deaths and has a mortality rate of over 50% in North America. The mortality rates varied in Hong Kong, being 35% for septicaemia cases and 20% for wound-infection cases.

V. vulnificus has the ability to cause wound infections, gastroenteritis, or a syndrome known as primary septicemia. Infections among healthy individuals are acute and do not have long-term consequences; ingestion of this bacterium causes mild symptoms such as vomiting, diarrhea, and abdominal pain usually within 16 hours.

In the immunocompromised population however, V. vulnificus can trigger further complications and has the potential to invade the bloodstream from an open wound or from the gastrointestinal tract, causing primary septicemia – a severe and life-threatening illnesses. This disease is characterized by fever, chills, septic shock that is soon followed by death. The three patients affected in Hong Kong had to either undergo amputation or excisional debridement.

V. vulnificus (There are much worse pictures than this one!)

Individuals are considered high-risk and vulnerable to infection if they have underlying chronic diseases or liver diseases [i.e. diabetes, cirrhosis, leukemia, lung cancer, acquired immune deficiency syndrome (AIDS), AIDS- related complex (ARC), or asthma requiring the use of steroid]. They are 80-200 times more likely to develop primary septicemia than healthy individuals.

The infective dose for healthy individuals is unidentified but for immunocompromised persons, septicemia occurs with doses of less than 100 total organisms. The incubation period is 1 – 7 days after eating and the duration of illness ranges from 2 to 8 days. Diagnostic methods are similar to those used to detect common foodborne pathogens and revolve around culturing of the organism from wounds, diarrheic stools, or blood. Methods such as the Quantitative Loop-Mediated Isothermal Amplification can quantitatively detect V. vulnificus in raw oysters with high speed, specificity, and sensitivity.

Measures that can be taken to prevent illness include:
• Avoid going into the ocean with open wounds (I think most people neglect this)
• Avoid eating raw or undercooked shellfish
• Before cooking: Discard any oysters with open shells
• During cooking: Boil for 3-5 minutes after shells open.
• After cooking: Discard any oysters with shells that did not open.

There have been many sporadic cases of V. vulnificus in Hong Kong over the past decade. Although the Centre for Health Protection of Hong Kong offers various Internet resources on how to prevent V. vulnificus infections, many of the victims are the elderly and are less likely to be able to access this information. I believe that more focus needs to be directed to relaying information on opportunistic foodborne pathogens to the elderly and immunocompromised in a manner that is not via the internet, i.e. various clinics and hospitals should offer them pamphlets and communicate with them verbally. In 2013, Health Canada has collaborated with the FAO, WHO, and the government of Japan to produce expert recommendations to the Codex Committee on Food Hygiene regarding V. vulnificus. Appropriate methods to monitor environmental hygiene and hygienic production, etc. can be found in Codex Alimentarius Guidelines on the Application of General Principles of Food Hygiene to the Control of Pathogenic Vibrio Species in Seafood.

Questions for thought:

1. Is this pathogen present in other geographical areas?

2. Which method(s) would be most suitable to detect the presence of this pathogen based on it transmission route?

References:

Codex Alimentarius (2010). International Food Standards. Guidelines on the Application of General Principles of Food Hygiene to the Control of Pathogenic Vibrio Species in Seafood. Retrieved from: http://www.codexalimentarius.org/standards/list-of-standards/

FDA (2015). Vibrio vulnificus. Bad Bug Book: Foodborne Pathogenic Microorganisms and Natural Toxins Handbook. Retrieved from: http://www.fda.gov/Food/FoodborneIllnessContaminants/CausesOfIllnessBadBugBook/ucm070473.htm

Han, F., Wang, F., & Ge, B. (2011). Detecting potentially virulent vibrio vulnificus strains in raw oysters by quantitative loop-mediated isothermal amplification. Applied and Environmental Microbiology, 77(8), 2589-2595.

Lee, S. E., Kim, S. Y., Kim, S. J., Kim, H. S., Shin, J. H., Choi, S. H.. . Rhee, J. H. (1998). Direct identification of vibrio vulnificus in clinical specimens by nested PCR. Journal of Clinical Microbiology, 36(10), 2887-2892.

Ma, J (2012). Vibrio vulnificus in food. Food Safety Focus, 72. Retrieved from: http://www.cfs.gov.hk/english/multimedia/multimedia_pub/multimedia_pub_fsf_72_01.html

Stone, J. (2015). With Global Warming, Expect More Deadly Vibrio Cases. Pharma & Healthcare. Forbes. Retrieved from: http://www.forbes.com/sites/judystone/2015/07/30/with-global-warming-expect-more-deadly-vibrio-cases/

Treasury Board of Canada Secretariat (2015). Food and Consumer Safety Action Plan. Retrieved from: https://www.tbs-sct.gc.ca/hidb-bdih/plan-eng.aspx?Org=0&Hi=85&Pl=403

Vibrio vulnificus (2013). Vibrio Illness (Vibriosis). Centers for Disease Control and Prevention. Retrieved from: http://www.cdc.gov/vibrio/vibriov.html

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Posted on November 13, 2015 by in Uncategorized

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Cyclospora Outbreaks are Hitting North America

Posted on November 13, 2015 by | 7 comments

Public health officials are warning about a series of Cyclospora outbreaks in US and Canada.

130730035854_cyclospora
Source: http://www.foodpoisonjournal.com/foodborne-illness-outbreaks/fda-on-29-state-cyclospora-outbreak-tied-to-mexican-cilantro/#.VkWSAPlViko

From May to August 2015, 546 peoples from 31 states in US became sick due to Cyclospora infection. The U.S. Food and Drug Administration (FDA) indicated that this outbreak has been linked to imported fresh produce, including cilantro from the Puebla region of Mexico.

Around the same time, a total of 97 Cyclosporiasis cases were reported in Canada, mainly in Ontario. Two cases were hospitalized, and no deaths were reported. The source of this outbreak was not identified.

On October 17, CFIA announced that Costco Wholesale Canada is voluntarily recalling Alpine Fresh brand snap peas in Ontario due to possible Cyclospora contamination. At least 22 illnesses have been linked to the recalled snap peas.

What is cyclospora?

Cyclospora, a microscopic parasite, causes an intestinal infection known as cyclosporiasis. The parasite is typically found in imported fresh vegetables and fruits such as basil, cilantro, pre-packaged salad mix, mesclun lettuce, snow peas, and raspberries. People usually become infected with Cyclospora by ingesting food or water that has been contaminated with feces, and this parasite is most commonly found in tropical and subtropical countries. Cyclospora cannot be passed directly from one person to another.

The life cyle of cyclosporiasis:
cyclospora_lifecycle
Source: http://www.cdc.gov/parasites/cyclosporiasis/biology.html

Why I haven’t heard of it before?

The public may not be as familiar with Cyclospora as some other foodborne pathogens because Cyclospora only came to medical attention about 40 years ago. This parasite was once primarily a concern for developing countries, but since the 1990s there have been more and more Cyclospora outbreaks in North America linked to contaminated imported fresh greens.

How serious is the illness?

Cyclospora is generally considered as a low-risk foodborne pathogen. Infected people usually experience watery diarrhea, stomach cramps, fatigue, weight loss, and abdominal bloating, while some people do not get sick at all. The illness may last from a few days to a month. People who have previously been infected can become infected again. The combination of 2 antibiotics, trimethoprim (TMP) and sulfamethoxazole (SMX), is used to treat Cyclospora infection.

How can it be prevented?

According to the US Centers for Disease Control and Prevention (CDC), avoiding food or water that might have been contaminated with stool is the most efficient way to prevent cyclosporiasis. Contaminated food may not look or smell spoiled. Both washing fresh produce and treating it with chlorine or iodine are not sufficient enough to eliminate the parasite. Microbial food safety hazards for fresh fruits and vegetables, including Cyclospora, must be controlled by addressing good agricultural practices (GAPs) and good manufacturing practices (GMPs).

Here is an educational video about Cyclospora:

https://youtube.com/watch?v=dVFRgmZpTfQ%3Frel%3D0%26autoplay%3D1

For more information, please check out (References):

CDC, 2015. Parasites – Cyclosporiasis (Cyclospora Infection). Retrieved from http://www.cdc.gov/parasites/cyclosporiasis/

CFIA, 2015. Food Recall Warning – Alpine Fresh brand Snap Peas recalled due to Cyclospora. Retrieved from http://www.inspection.gc.ca/about-the-cfia/newsroom/food-recall-warnings/complete-listing/2015-10-17/eng/1445121740221/1445121744219

Cinnaminson N.J., 2015. Cyclospora Contamination and Infection Risks. Retrieved from http://www.webwire.com/ViewPressRel.asp?aId=200735

Food Safety News, 2015. CDC: Cyclospora Outbreak Linked to Mexican Cilantro Sickened 546 People. Retrieved from http://www.foodsafetynews.com/2015/09/cdc-recent-cyclospora-outbreak-linked-to-mexican-cilantro-is-over/#.VkWGv_lViko

Mulholland A., 2015. Cyclospora outbreak: What you need to know about the parasite, illness. Retrieved from http://www.ctvnews.ca/health/cyclospora-outbreak-what-you-need-to-know-about-the-parasite-illness-1.2509552

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Cholera Outbreak in Africa

Posted on November 12, 2015 by | 4 comments

Cholera, an infection that is commonly found in central Africa, has affected thousands of millions of people every year, according to the World Health Organization (WHO). Cholera is an acute diarrheal disease that is caused by the strains of a bacterium called Vibrio cholerae. V. cholerae is a pathogen that colonizes the small intestine and causes symptoms such as watery diarrhea and vomiting. If left untreated, people will suffer from severe dehydration and leads to death within hours.

During March 2015, there were more than 10 students hospitalized after consuming cooked cassava tuber, which is a kind of African salad in Abakaliki, the capital of Ebonyi in Nigeria. They suffered from stooling right after the meal and went to hospital as the condition became worsen.

After investigation, they confirmed that this is a case of cholera, and the food was contaminated by flies, the director of Rural health, Ministry of Health, Dr. Christian Achi explained.

Cassava is a type of plant that is widely eaten as staple food in developing countries. That means many people eat it in a daily basis and if it is infected by V. cholerae, this can cause a huge outbreak of cholera in Africa. Therefore, cooking food thoroughly and maintain hygiene is very important in these areas to prevent any disease outbreak.

 

Many of us think that keeping our equipment clean and fully cook food are the essential things that we should do and are enough to prevent any disease. We never thought of flies to be the transmission route of bacteria. Flies carry bacteria from contaminated food to other non-contaminated food and cause people to be infected. Therefore, keeping the environment clean to avoid any insects from contacting food is also a key to preventing cholera.

According to the data provided by WHO, almost 45% of cholera cases were reported from Africa in 2013. Although the number of reported cases has already decreased compare to previous years, the reason why there are still more than ten thousand reported cases this year is probably due to flooding in Africa. This is because another way cholera contaminate food other than flies is through water. Flooding causes all the food soaked in dirty water and thus be contaminated by V. cholerae very easily. Also, due to all kinds of economical situations and limited water resources, people will drink water without processing such as boiling or filtering. As a result, cholera is widely spread in these areas where there is inadequate environmental management.

Cholera vaccineThe method people use to treat cholera is by oral rehydration salts (ORS), a treatment that is indicated by WHO. Severe diarrhea will leads to dehydration so ORS is a very effective and efficient way on rehydrating people. Anitibiotics are also used to shorten diarrhea duration. To control the outbreak of cholera due to weather such as raining season, they will introduce cholera vaccines to people. The following video shows the situations people are facing in Africa and how they are treating cholera using vaccination. In order to prevent cholera outbreak, improving sanitation and access of safe drinking water are the keys, which are also indicated on the video. We shall not neglect the importance of improving environmental conditions such as household hygiene, water filtration, development of water pipe system by treating disinfectants, etc. These strategies can upgrade their living conditions and minimize the chance of getting infected.

 

Sources:

http://allafrica.com/stories/201503250132.html

http://www.who.int/mediacentre/factsheets/fs107/en/

http://www.who.int/gho/epidemic_diseases/cholera/en/

http://www.voanews.com/content/who-cholera-outbreaks-in-africa-middle-east/3018398.html

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Vibrios: Rare but Need to Notice

Posted on November 12, 2015 by | 6 comments

Eating raw and cold shellfish can be such enjoyment under the hot sun. Living in BC makes us have the advantaged access to fresh and tasty shellfish. However, sometimes such delicacy comes with ricks and the major ones are the toxins produced by other organisms that live with shellfish.
oysters

According to Health Canada, Vibrios are toxin-producing bacteria that can be found naturally in water, fish and shellfish. Its main transmission is through consuming contaminated foods and drinks. Most of the pathogenic Vibrios are salt-loving, which means they live in oceans. For example, Vibrio parahaemolytius that caused an outbreak in Canada in the past summer.

During May to September 2015, 82 cases of Vibrio parahaemolytius were reported (60 of them were in BC) to Public Health Agency of Canada. All cases were related to consuming raw shellfish especially oysters. Due to this outbreak, oysters harvested from British Columbia coastal waters for raw consumption on or before August 18, 2015 were recalled from the marketplace.

In response to the the outbreak, Vancouver Coastal Health issued a statement on August 2, 2015 requiring restaurants to serve oysters after cooking as only oyster harvested from BC could be served raw at that time. Fortunately, this outbreak ended fast and well. The latest case was reported on September 3 and only one person was hospitalized. No death case was reported.

Symptoms:
People infected by Vibrio parahaemolyticus usually get mild intestinal illness. After 12 to 24 hours of incubation, most people develop one or more of the following symptoms: diarrhea (watery), stomach cramps, nausea, vomiting, fever and headache. Another pathogenic type of Vibrios, V. vulnificus can cause chills, abnormal low blood pressure and bacteria present in blood to infected individuals especially to the vulnerable. Symptoms last about three days and treatments are seldom required.

More sever than two types above, people infected by V. cholerae usually develop one or more of the following symptoms after one to three days of incubation: diarrhea (watery), leg cramps, vomiting, dehydration and low blood pressure. Due to the rapid loss of body fluid, treatment (re-hydration with fluid containing electrolytes) or antibiotics in serious cases is required.
Vibrio

Prevention:
1. Boil shellfish in shell until open and continue boiling for 5 minutes
2. Steam until shellfish open and continue steaming for 9 minutes
3. Do not eat shellfish that is not open
4. Boil shucked shellfish for 3 minutes or fry them in oil for >10 minutes at 375°F (190°C)
5. Drink water from reliable sources

There is a video on youtube that gives a brief intro of Vibrios, check this out if you are interested:

Sources:
http://www.phac-aspc.gc.ca/phn-asp/2015/vibrioparahaemolyticus-eng.php

31 Vibrio Cases Prompt BC Health Officials to Require Cooking of BC Oysters


http://www.bccdc.ca/dis-cond/a-z/_v/Vibrio/default.htm
http://www.healthlinkbc.ca/healthtopics/content.asp?hwid=ug2972
http://healthycanadians.gc.ca/eating-nutrition/risks-recalls-rappels-risques/poisoning-intoxication/poisoning-intoxication/index-eng.php

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Warning: Water supply contaminated with the parasite Cryptosporidium

Posted on November 9, 2015 by | 12 comments

Most North Americans and Europeans consume fresh tap water daily without any concern. These developed countries have advance filter systems, implemented chlorine treatments and/or radiation treatments; such as ultraviolet light to kill pathogens. Since the water supply is treated many would believe the source is safe. Is that always true?

Cryptosporidium

This past August the water supply of several Lancashire districts in England (Blackpool, Preston, Chorley, Fylde, Wyre and South Ribble) was contaminated with an infectious parasite, Cryptosporidium. About 300,000 Lancashire households were put on alert. This parasite causes the disease cryptosporidiosis, which includes symptoms stomach cramping, dehydration, vomiting, nausea, and weight-loss. The most common symptom is watery diarrhea. These symptoms may appear after 2 days and last up to 30 days after infection. Chronic or fatal illness maybe develop in susceptible population; which includes immunocompromised, young children, and the elderly.

This parasite is a concern when it comes to the consumption of tap water because it is extremely resistant to chlorine, therefore; the chlorinated treatments have little effect on the parasite. The water company United Utilities advised everyone to boil their water before consumption.

Due this parasitic discovery panic was all over. A local mentioned, “This water thing in Blackpool is a nightmare just went to the corner shop and they were on the last few bottles!” Major supermarkets were running short bottled water since “nobody can drink the water in Blackpool because it’s contaminated and now there’s no water left in any shops.” With the high demand of water and the short supply, people were selling water on the internet for ridiculously high prices.

Water shortage in Supermarkets

United Utilises reassured the public that they were monitoring Cryptosporidium levels carefully through continuous testing. Only trace amounts remain in the source after the first week of August, United Utilities issued boiled water notice until mid-August.

This is a rare occurrence. In 2005 an outbreak of cryptosporidium affected 231people in North Wales and the Cymrus Welsh Water was fined £60,000 and spent another £70,000 to compensate the affected individuals. As for the cryptosporidium contamination from August there were no confirm cases of sickness. An outbreak was avoided due to the quick action United Utilities took.

Here’s a Brief video for your interest!
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Sources of contamination (fecal-oral route):
• Animal waste
• Water sources

Prevention:
• Boil water
• Proper hygiene
• Wash hands

Treatment:
• No specific drug to kill organism
• diarrheal medicine may help slow down diarrhea
• Consume lots of water

What is your opinion on drinking tap water? Do you boil or treat your water?

Sources:
http://www.express.co.uk/news/uk/596681/Lancashire-supermarkets-bottled-water-parasite
http://www.lenntech.com/processes/disinfection/regulation-eu/eu-water-disinfection-regulation.htm
http://www.bccdc.ca/dis-cond/a-z/_c/Cryptosporidium/overview/Cryptosporidium.htm#heading2
http://www.cdc.gov/parasites/crypto/
http://www.pollutionsolutions-online.com/news/water-wastewater/17/breaking_news/how_did_cryptosporidium_find_its_way_into_the_lancashire_water_supply/35744/

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