Category Archives: food contamination

Research – Retrospective validation of whole genome sequencing-enhanced surveillance of listeriosis in Europe, 2010 to 2015


More than half of the severe listeriosis cases in the European Union belong to clusters, many of which are not being picked up fast enough by the current surveillance system, suggests a new article published in Eurosurveillance.

Invasive infection by () leads to relatively rare but serious food-borne disease mainly affecting elderly people, immunocompromised individuals and pregnant women. Clinical manifestations include sepsis and infection of the central nervous system, which can lead to lifelong sequelae or death [1,2]. Pregnancy-associated listeriosis can result in preterm birth, miscarriage or stillbirth [2,3]. In the European Union and European Economic Area (EU/EEA), 2,224 human cases of invasive listeriosis were reported in 2015, with an overall case fatality rate of 18.8% [4]. Reported numbers of cases of listeriosis suggest that the incidence of disease slightly increased over the period of 2010–15. The incubation period of listeriosis is usually 3 to 21 days, but can be as long as 67 days, depending on the clinical form of the disease [5]. Patients frequently have underlying conditions and/or are elderly, which limits the collection of exposure data in some cases. On epidemiological grounds, most cases are considered sporadic and detected outbreaks usually involve small numbers of patients, which limits statistical power in analytical epidemiological studies. As a result, most reported cases of listeriosis are difficult to link to a specific food product or food business operator.

is able to form biofilms, grow at refrigeration temperature, high salt and nitrite concentrations, and can be resistant to disinfectants [6,7]. These properties contribute to its ability to persist and multiply in the food-processing environment and make it difficult to control. In the United States (US), a nationwide subtyping of using pulsed-field gel electrophoresis (PFGE) was introduced in 1998. During the following 6 years, there was a more than fivefold increase in the number of outbreaks where a common food vehicle could be identified [8]. In the subsequent 10 years, the introduction of detailed food history gathering for all listeriosis patients resulted in a further increase in the number of solved outbreaks per year, as well as a reduction of the number of cases per outbreak [9].

PFGE is, however, time-consuming and difficult to standardise. In recent years, it has been demonstrated that whole genome sequence (WGS)-based subtyping can provide substantial additional discrimination and, consequently, can be of benefit to outbreak investigations [911]. Within the EU/EEA, listeriosis is one of the priority diseases for which supranational WGS-enhanced surveillance will be initiated in 2018 [12]. The work presented here supports the preparation for this surveillance system through a large-scale, retrospective, multi-centre study on isolates from human cases from EU/EEA countries by covering the comparison and validation of analytical pipelines, the assessment of the epidemiological concordance of the results and the potential impact on public health [13]. The analytical pipelines are based on the gene-by-gene approach recommended by the PulseNet International global consortium [1417].

UK Scotland – Cyclospora in travellers returning from Mexico

HPS Cyclospora_LifeCycle201

Public Health England (PHE), Public Health Wales (PHW), Health Protection Scotland (HPS) and the Health Protection Service Northern Ireland (HPSNI) are investigating an increase in cases of Cyclospora cayetanensis infection in travellers who have recently returned from Mexico. This is the fourth successive year since 2015 that cases of the infection have been reported in travellers returning from Mexico.

As of 3 August 2018, 63 laboratory-confirmed cases of Cyclospora cayetanensis have been reported in England, Scotland and Wales. Where information is available, 55 (87%) report travel outside the UK, of which 49 (89%) report recent travel to Mexico. Where information is available, cases have stayed at several different hotels in the Cancun and Riviera Maya region suggesting the source is likely to be a foodstuff that has been distributed to hotels throughout the region.

Cyclospora cayetanensis is a protozoan parasite that infects humans and other primates. Infection can cause diarrhoea, abdominal cramping, nausea, flatulence, loss of appetite, fatigue, low-grade fever and weight loss. Infection without symptoms is also reported. Infections in HIV positive people and those with other immune deficiencies can be more severe.

Infection is commonly derived from food or water contaminated by human faeces. The foods commonly involved are soft fruits such as raspberries and salad products such as coriander, basil and lettuce. The risk of infection presented by imported foods is considered to be low.

Advice for travellers on the prevention of Cyclospora is available from Health Protection Scotland:

Poland – Shigella sonnei outbreak linked to Rainbow Gathering

Outbreak News Today 

Shigella - kswfoodworld

Image CDC

European health officials are reporting a Shigella sonnei outbreak among participants of a Rainbow Gathering in the south-east of Poland.

Between 5 and 10 August 2018, 45 participants presented with gastroenteritis symptoms, 14 of these tested positive for Shigella sonnei. The event took place between 13 July and 11 August and so it is likely that most participants, which come from many countries within the EU, have now left the area.

Last year, a typhoid outbreak was linked to the European Rainbow gathering that took place in Tramonti di Sopra, Friuli-Venezia Giulia region, Italy.



USA – Chipotle Update: Stool Sample Results Returned by CDC Test Positive for Clostridium perfringens

Delaware Health 


Image CDC

  • Clostridium perfringens is a foodborne disease that occurs when food is left at an unsafe temperature.
  • Although food samples tested negative for C. perfringens bacteria, the stool samples tested positive for the toxin that C. perfringens forms in the gastrointestinal tract.
  • A specific food has not been able to be identified as the source of illness. Ongoing food and stool testing is being conducted by the CDC lab.
  • “I am extremely proud of our team! This investigation included countless hours of phone calls and interviews along with multiple inspections. We are also appreciative of our community for being very cooperative during this investigation and for understanding our work in protecting the public’s health. We are also thankful for the work of our partners at the Ohio Department of Health and the CDC,” said Delaware County Health Commissioner Shelia Hiddleson.
  • In response to this outbreak, Brian Niccol, CEO of Chipotle Mexican Grill stated that “Chipotle Field Leadership will be retraining all restaurant employees nationwide beginning next week on food safety and wellness protocols.” Click here for complete statement.
  • Health District staff identified 647 people who self-reported gastrointestinal symptoms after consuming food from the Chipotle on Sawmill Parkway between Thursday July 26 – Monday July 30, 2018.


India -Food poisoning in another Mumbai school; 16 children, teacher rushed to hospital

The Indian Express

In the second episode of mass hospitalisation from a school within a week, 16 children and a teacher were rushed to hospital after complaints of food poisoning.

According to Dr Usha Mohprekar, medical superintendent in MT Agrawal Hospital in Mulund, all the patients complained of vomiting and stomach pain but “all are stable”.

The incident occurred in a private organisation-run Sahyadri Vidyamandir school in Bhandup on Thursday around 12.35 pm.

“The children suffered from food poisoning,” a civic official said, adding that school staff and ward’s medical officer have reached the spot.

READ | Mumbai: 12-year-old girl dies, 197 hospitalised on suspicion of medicine poisoning in BMC school

USA – Health officials studying church picnic as Salmonella outbreak hits 50

SE Missourian

CDC Image


Authorities are investigating a possible connection between an ongoing salmonella outbreak and a recent church picnic as the number of confirmed sick in Perry County has risen to 50.

Sheila Hahs, Perry County Health Department communicable-disease coordinator, said Friday no cause has been determined.

Hahs said the department continues to work with the Missouri Department of Health and Senior Services (DHSS), which has begun distributing a survey seeking in-depth information about the behavior of individuals who attended the St. Vincent de Paul Seminary Picnic Aug. 3, 4 and 5.

The introduction to the 45-question online survey, titled “Church Picnic Salmonella Outbreak 2018,” states at least some of the reported ill attended the picnic. The survey asks participants to detail any symptoms, treatments, whether they brought or prepared food at the picnic and which foods, if any, they consumed while there.

Hahs said the survey is a starting point, after which representatives from the Perry County Health Department will conduct individual follow-up interviews with people who were sickened.

USA – Burien Fresh Smoothies in Washington Associated With Salmonella Outbreak

Food Poisoning Bulletin kswfoodworld Salmonella

Burien Fresh Smoothies in Burien, Washington is associated with a Salmonella Braenderup outbreak, according to a press release by Seattle-King County Public Health Department. At least seven people are sick, and two people were so ill that they were hospitalized. Officials have not identified the source of illness.

Seven people from three separate parties have been ill after consuming food at the restaurant from August 6 through August 8, 2018. The people who were hospitalized have since recovered and have been released.

Five of the seven patients have tested positive for Salmonella Braenderup. Officials are waiting for genetic fingerprint results, and results from food samples taken from the restaurant.