Salmonella in pesto triggers Irish recall

Brisbane has fabulous produce and seafood, befitting a costal sub-tropical town.

Sure, it’s way too hot for three months in the summer, but the weather is ideal the rest of the year.

A friend of mine – a food safety professional — was telling me yesterday about this snapper he got, straight of the trawler, and the pesto sauce he made to go with it.

I really try not to be Debbie/Dougie downer when people tell me their proud achievements, so I didn’t go into all the outbreaks on pesto from uncooked basil.

Usually it’s cyclospora, but the Food Safety Authority of Ireland has issued a public notification that Dunnes Stores and Spar are initiating a recall of their own brand pestos, due to the possible presence of Salmonella. Consumers who have bought the implicated batches should dispose of the product or return it to the place of purchase.

19 sickened: ‘Dodgy salad’ behind Celtic Salmonella outbreak

I always worry about the homemade pesto.

The culprit in the Celtic Park salmonella outbreak was probably a dodgy ham and mozzarella salad, a report has revealed.

pesto.basil.cyclosporaNineteen guests at the Glasgow ground were struck down with vomiting and diarrhea last September.

Despite initial suggestions that a lamb dish was the chief suspect, months of sophisticated testing have pointed towards an Italian delicacy.

The investigation by the public health protection unit of NHS Greater Glasgow and Clyde (NHSGGC) found that all those struck down had the starter of “prosciutto ham, mozzarella, and home-made pesto dressing”.

Two people were admitted to hospital following the outbreak but all the victims made a full recovery.

It is believed they were all at the ground for either the Celtic v Motherwell game on Sunday 21st September, or the Celtic v Hearts game three days later.

Investigators carried out an assessment of the food-making process for each component of the starter, even down to the draining of the mozzarella balls.

But it was impossible to test the actual ingredients used in the starters because they had all either been eaten or thrown away.

Survival of Salmonella on basil plants and in pesto

Yesterday at the school tuck shop, we made 280 sushi rolls (I cooked the chicken but felt naked without my misplaced thermometer, Chapman is mailing me more) 70 sausage rolls and 10 orders of pesto pasta.

basil.salmonellaThe pesto is part of the garden-to-kitchen initiative. I have my food safety concerns about such things but am trying to not alienate all the parent volunteers at once.

They got messages about handwashing and rice storage this week.

And I was also in charge of prepping the pesto pasta, so I made sure it was heated.

But, as reported by Eckner et. al, leafy greens, including fresh herbs, have repeatedly been involved in outbreaks of foodborne disease. Although much effort has been put into studying leafy greens and products such as head lettuce and baby leaves, less is known about fresh leafy herbs, such as basil.

The goal of this study was to investigate the survival of Salmonella on basil plants and in pesto. A mix of three Salmonella strains (Reading, Newport, and Typhimurium) was inoculated onto basil leaves and pesto and survived during the experimental period.

Whereas the mix of Salmonella survived in pesto stored at 4°C for 4 days, Salmonella was recovered from inoculated leaves for up to 18 days at 20 to 22°C. Although the steady decline of Salmonella on leaves and in pesto suggests a lack of growth, it appears that pesto is a hostile environment for Salmonella because the rate of decline in pesto was faster (0.29 log CFU/g/day) than on leaves (0.11 log CFU/g/day).

pesto.basil.cyclosporaThese findings suggest that the dilution of contaminated ingredients and the bactericidal effect of the pesto environment helped to further reduce the level of enteric organisms during storage, which may have applications for food safety.

Survival of Salmonella on basil plants and in pesto


Journal of Food Protection®, Number 2, February 2015, pp. 240-476, pp. 402-406(5)

Eckner, Karl F.; Høgåsen, Helga R.; Begum, Mumtaz; økland, Marianne; Cudjoe, Kofitsyo S., Johannessen, Gro S.

46 sickened; Shigella outbreak traced to imported basil in Norway, 2011

While the U.S. extends a comment period for something about improving spice safety (raw herbs have been a known food safety risk for decades), Norway reports on a 2011 outbreak of Shigella sonnei linked to basil that sickened at least 46 people updating previous reports.

On 9 October 2011, the University Hospital of North Norway alerted the Norwegian Institute of Public Health (NIPH) about an increase in Shigella sonnei infections in Tromsø. The isolates had an identical ‘multilocus variable-number tandem repeat analysis’ (MLVA) profile. basil.salmonellaMost cases had consumed food provided by delicatessen X. On 14 October, new S. sonnei cases with the same MLVA-profile were reported from Sarpsborg, south-eastern Norway. An outbreak investigation was started to identify the source and prevent further cases. All laboratory-confirmed cases from both clusters were attempted to be interviewed.

In addition, a cohort study was performed among the attendees of a banquet in Tromsø where food from delicatessen X had been served and where some people had reported being ill. A trace-back investigation was initiated. In total, 46 cases were confirmed (Tromsø= 42; Sarpsborg= 4). Having eaten basil pesto sauce or fish soup at the banquet in Tromsø were independent risk factors for disease. Basil pesto was the only common food item that had been consumed by confirmed cases occurring in Tromsø and Sarpsborg. The basil had pesto.basil.cyclosporabeen imported and delivered to both municipalities by the same supplier. No basil from the specific batch was left on the Norwegian market when it was identified as the likely source. As a result of the multidisciplinary investigation, which helped to identify the source, the Norwegian Food Safety Authority, together with NIPH, planned to develop recommendations for food providers on how to handle fresh plant produce prior to consumption.

A fresh perspective on alleged pesto outbreak in Italy

It’s better to rely on locals who know their stuff, so I turned to our Italian food safety friend, Luca Bucchini to clarify the alleged-botulism-in-pesto story. He writes:

There was probably no botulin toxin in the Italian basil pesto that sent more than 100 people to the emergency departments across Italy. Of the 100, 10 have been initially hospitalised, but 8 were later sent home: none had symptoms which suggested botulism. While tests on products and humans are still pending, the toxin has yet to be found in any sample.

The company, Bruzzone and Ferrari, which has been producing basil for pesto for two centuries, had identified a “potentially pathogenic microorganism” in a lot of its pesto: it is widely believed that the organism was C. botulinum, the bacterium which basil.salmonellacan, under certain conditions, produce the lethal toxin. The product, which is a fresh sauce requiring refrigeration, was already on the market: when the shelf life of a product is relatively short and time required for testing is relatively long, products are shipped before the results of the testing are known. This procedure is often required by retailers. When Bruzzone and Ferrari realised that they had a positive finding for the pathogen, though not for the toxin, they decided to issue a recall; a public recall is uncommon in Italy.

Italy’s Ministry of Health, usually stingy with information, issued a Press Release ( on July 20, 2013, calling the incident an “alarm” and explained that the botulin toxin is potentially fatal. However, it failed to mention the retail brands under which the product was sold, and did not offer advice to consumers, for example on when to seek medical care. Only the lot, the sell-by date and the producer’s name were mentioned; it was assumed that consumers are able to scan the back of the label and identify the small print needed to identify the producer. The press release also suggested that products were mostly off the shelf and the recall was limited. Ministry of Health press releases are immediately taken up by the main press agencies, and automatically become major news.

It soon became apparent that 15,000 jars were affected, and that many consumers had eaten the product, which had been on the market for at least a week; there was no information for them in the official communication. Panic ensued. Officials communicated sparingly, with the exception of Liguria, the region where the company is based. Hospitals were slow to explain that no cases were confirmed and that people without symptoms did not need hospitalisation; the Facebook site of Bruzzone & Ferrari was the pesto.basil.cyclosporaonly formal source of information, with only a few independent media outlets providing further details. The affected lot had been sold under several brands, including those of Italy’s top supermarket chains. The supermarket chains posted alert signs in shops and frantically e-mailed and phoned customers with loyalty cards to inform them of the recall; they probably hoped to avoid going public. As consumers reported about the calls received on Facebook and on other sites, some eventually capitulated and published on their website a recall notice, while others are still silent.

At this point in time, it seems likely that there was no toxin in most or all jars, and that people sought medical attention for reasons unrelated to product content. Some suspect that other pathogens may be present; however, no specific information supports this, and reported symptoms by few patients (vomit, diarrhea) may be unrelated to the exposure.

Nevertheless, the presence of the toxin in some jars cannot be excluded. The product does not appear to be heat-treated; it is part of a broad global trend to produce raw, semi-raw fresh products which require refrigeration. The pH of the product is permissive for growth of botulin (specifications: 4.8-5.8); it is rich in oil providing anaerobic conditions; it is used on pasta as a sauce without cooking; it has a shelf life of 30 days. While the product is to be refrigerated, the cold chain, especially in summer, with ambient temperatures above 30 C, is often not reliable: retailers often don’t prioritise temperature control. Consumers may not understand the difference between shelf-stable pesto (which is more common) and the refrigerated variety, or underestimate the importance of refrigeration.

Though food safety officials praised the company for not hesitating to issue a public recall, magistrates, as it is usual in Italy, were quick to start a criminal investigation for alleged unintentional injuries. In Italy, companies fear issuing precautionary recalls as magistrates generally try and convict in criminal court those who publicly confess to the mere presence of a pathogen in their products. This has been a factor in the hesitation of businesses to embrace European food law which requires issuing immediate recalls.

Overall, it is early to draw final conclusions from this episode. Hopefully, the results of the testing will be made public and confirm that there was no outbreak (incidentally, Italy has an ongoing foodborne Hepatitis A outbreak with hundreds of cases of which were little is being said). It is perhaps time to question products which, while nicely fresh, depend on the cold chain for being safe from botulin. It is quite clear that the authorities, and particularly the Ministry of Health, need risk communication training: consumers need to reliably identify products, get quickly rid of them, and not rush to the ER if they don’t need to.

50 sick: the link between Simon Cowell, botox and pesto?

Food poisoning can be caused by Clostridium botulinum, a bacteria that can form spores which require extra processing or careful control of temperature. Botox, derived from botulinum, is used by vain people.

UK’s Daily Mail, you are a gift that keeps giving, after reporting “dozens of people have been hospitalized in Italy after eating pesto sauce contaminated with Botox. … Tests on the pesto The X-Factor final Photo Call, Londonshowed the presence of the bacteria Clostridium botulinum, which produces the toxin Botulinum, used cosmetically by television personalities such as Simon Cowell. When ingested the toxin causes a life-threatening kind of food poisoning.”

The local producer responsible for the outbreak has been growing the area’s renowned basil for almost two centuries, but only recently started selling pre-prepared jars of the sauce. 

The company said, “We made the discovery during our own tests and analysis of our fresh product, non-pasteurized product, which contains no preservatives.”

Refrigeration would help.

46 sick with Shigella from imported fresh basil in Norway

Eurosurveillance reports today an outbreak of Shigella in Norway that sickened at least 46 people.

Two municipalities were involved. A large cluster (42 cases) was concentrated in north Norway, while a small cluster (4 cases) occurred in the south-east region. Epidemiological evidence and traceback investigations have linked the outbreak to the consumption of imported fresh basil. The product has been withdrawn from the market. No further cases have been reported since 25 October.

On 9 October 2011, the Department of Infectious Disease Epidemiology at the Norwegian Institute of Public Health was informed by the Municipal Medical Officer and the Local Food Safety Authority in Tromsø (northern Norway) about an unusually high number of cases of gastrointestinal disease caused by Shigella sonnei.

A delicatessen and catering company located in the centre of Tromsø received several complaints from customers who had fallen ill with gastrointestinal symptoms after having eaten food items from there.

On 14 October, a small cluster of cases who had not been to Tromsø were reported and the outbreak was classified as national.

An outbreak case was defined as a person with gastrointestinal symptoms with laboratory confirmed infection with S. sonnei with indistinguishable multiple-locus variable number of tandem repeats analysis (MLVA) profiles in Norway after 1 October 2011.

Traceback investigations of ingredients in the pesto served in Tromsø are still ongoing. The same distributer that provided the fresh basil to the catering company in Tromsø also delivered fresh basil to the restaurant implicated in the second cluster in south-east Norway. The distributor imported this herb from a country outside the European Union and has voluntarily withdrawn it from the market. The National Veterinary Institute analysed samples of pesto and other ingredients from the catering company in Tromsø. Samples available for analysis have been negative. An epidemic intelligence information system (EPIS) enquiry has been posted to determine whether other European countries have observed a similar increase in cases infected with S. sonnei. So far, no other countries have reported any recent increase in cases that can be linked to this outbreak.

No Chef’s Challenge this year after 200 sick with cyclospora last year

In May, 2010, at least 43 people were lab-confirmed to be sickened with cyclospora and over 200 displayed symptoms of illness after attending the Chef’s Challenge, a fundraiser for the Big Sisters of Sarnia-Lambton in Ontario, Canada.

"It wasn’t something we were able to go ahead with this year given the incident that took place," said executive director Kathy Alexander.

Local health types figured the source of the cyclospora was a cool pesto crunch but couldn’t identify the ingredient.

Cyclospora in Sarnia sickens 200, blamed on cool pesto crunch; health types can’t indentify ingredient; try basil

On July 7, 1997, a company physician reported to the Alexandria Department of Health (ADOH) that most of the employees who attended a corporate luncheon on June 26 at the company’s branch in Fairfax, Virginia, had developed gastrointestinal illness (Centres for Disease Control, 1997). On July 11, the health department was notified that a stool specimen from one of the employees who attended the luncheon was positive for Cyclospora oocysts. Many others tested positive. It was subsequently revealed in a July 19, 1997, Washington Post story citing local health department officials that basil and pesto from four Sutton Place Gourmet stores around Washington D.C. was the source of cyclospora for 126 people who attended at least 19 separate events where Sutton Place basil products were served, from small dinner parties and baby showers to corporate gatherings (Masters, 1997a). Of the 126, 30 members of the National Symphony Orchestra became sick after they ate box lunches provided by Sutton Place at Wolf Trap Farm Park.

In May 2001, 17 people in British Columbia (that’s in Canada) were sickened with cyclospora associated with basil from Thailand. In 2005, 300 people in Florida were sickened with cyclospora from fresh basil.

My aunt was part of that outbreak.

So when Lambton Community Health Services says it has closed its investigation of last month’s cyclospora outbreak in Sarnia, Ontario (also in Canada) that sickened more than 200 people and the suspect food was a cool pesto crunch (it was a chef showoff fundraiser), but can’t identify the ingredient, I’m leaning towards the basil.

Dudley Do-Right The Canadian Food Inspection Agency continues to investigate.