What foods are most likely to cause illness by shiga toxin-producing Escherichia coli (STEC) and how best to control secondary infections

Two abstracts attempt to provide guidance to these important questions to reduce the toll of STEC.

FAO and WHO conclude shiga toxin-producing Escherichia coli (STEC) infections are a substantial public health issue worldwide, causing more than 1 million illnesses, 128 deaths and nearly 13 000 Disability-Adjusted Life Years (DALYs) annually.

To appropriately target interventions to prevent STEC infections transmitted through food, it is important to determine the specific types of foods leading to these illnesses.

An analysis of data from STEC foodborne outbreak investigations reported globally, and a systematic review and meta-analysis of case-control studies of sporadic STEC infections published for all dates and locations, were conducted. A total of 957 STEC outbreaks from 27 different countries were included in the analysis.

Overall, outbreak data identified that 16% (95% UI, 2-17%) of outbreaks were attributed to beef, 15% (95% UI, 2-15%) to produce (fruits and vegetables) and 6% (95% UI, 1-6%) to dairy products. The food sources involved in 57% of all outbreaks could not be identified. The attribution proportions were calculated by WHO region and the attribution of specific food commodities varied between geographic regions.

In the European and American sub-regions of the WHO, the primary sources of outbreaks were beef and produce (fruits and vegetables). In contrast, produce (fruits and vegetables) and dairy were identified as the primary sources of STEC outbreaks in the WHO Western Pacific sub-region.

The systematic search of the literature identified useable data from 21 publications of case-control studies of sporadic STEC infections. The results of the meta-analysis identified, overall, beef and meat-unspecified as significant risk factors for STEC infection. Geographic region contributed to significant sources of heterogeneity. Generally, empirical data were particularly sparse for certain regions.

Care must be taken in extrapolating data from these regions to other regions for which there are no data. Nevertheless, results from both approaches are complementary, and support the conclusion of beef products being an important source of STEC infections. Prioritizing interventions for control on beef supply chains may provide the largest return on investment when implementing strategies for STEC control.

Second up, in 2016, we reviewed preventive control measures for secondary transmission of Shiga-toxin producing Escherichia coli (STEC) in humans in European Union (EU)/European Free Trade Association (EEA) countries to inform the revision of the respective Norwegian guidelines which at that time did not accommodate for the varying pathogenic potential of STEC.

We interviewed public health experts from EU/EEA institutes, using a semi-structured questionnaire. We revised the Norwegian guidelines using a risk-based approach informed by the new scientific evidence on risk factors for HUS and the survey results.

All 13 (42%) participating countries tested STEC for Shiga toxin (stx) 1, stx2 and eae (encoding intimin). Five countries differentiated their control measures based on clinical and/or microbiological case characteristics, but only Denmark based their measures on routinely conducted stx subtyping. In all countries, but Norway, clearance was obtained with ⩽3 negative STEC specimens. After this review, Norway revised the STEC guidelines and recommended only follow-up of cases infected with high-virulent STEC (determined by microbiological and clinical information); clearance is obtained with three negative specimens.

Implementation of the revised Norwegian guidelines will lead to a decrease of STEC cases needing follow-up and clearance, and will reduce the burden of unnecessary public health measures and the socioeconomic impact on cases. This review of guidelines could assist other countries in adapting their STEC control measures.

Mapping of control measures to prevent secondary transmission of STEC infections in Europe during 2016 and revision of the national guidelines in Norway

Cambridge University Press vol. 147

  1. Veneti(a1)(a2)H. Lange (a1)L. Brandal (a1)K. Danis (a2) (a3) and L. Vold 

DOI: https://doi.org/10.1017/S0950268819001614
https://www.cambridge.org/core/journals/epidemiology-and-infection/article/mapping-of-control-measures-to-prevent-secondary-transmission-of-stec-infections-in-europe-during-2016-and-revision-of-the-national-guidelines-in-norway/1990D2338B220F80F0E683DF6F622A40

Norwegian Authority warns pregnant women to avoid ginger supplements

The Norwegian Food Safety Authority warns pregnant women and women planning to become pregnant to avoid ginger supplements and ginger-containing shots.

Will Chu of Nutra reports the warning comes after the Danish Technical University (DTU) and the Danish Veterinary and Food Administration carried out a new risk assessment that found a higher abortion risk in animal studies.

In the report, the DTU said the results did not exclude the possibility that large ginger quantities could also increase this risk in humans.

“The DTU Food Institute concludes that in many cases ginger root ingestion from a single ginger shot will be larger (up to 20-23 grams (g) per day) than the fresh or dried amount typically eaten in the diet. ​

“Experiments in rats indicate that ginger can affect the normal foetal development,”​ says the report​, dated 21 December 2018.

 “The studies conducted so far in humans did not investigate whether ginger can have a harmful effect early in pregnancy. Animal studies suggest that it may be a particularly sensitive period. ​

“There is a small safety margin between the daily dose linked to harmful effects during pregnancy in rats and the amount of ginger that can be consumed with one ginger shot,”​ the report continues.

Along with the Norwegian Food Safety Authority, the Norwegian Institute of Public Health assessed the Danish report, supporting its conclusions and issuing the warning against taking ginger shots and supplements with ginger.

2 dead, 2,000 sick from campy in water in Norway

MRT reports that a  patient from a southern Norway island with contaminated water has died after being hospitalized with gastrointestinal symptoms, authorities said Thursday.

Erik Vigander of the regional hospital entity in southern Norway said the bacteria Campylobacter was found in the patient’s system. That’s the same bacteria identified in other people sickened since E. coli was found in a reservoir that supplied drinking water for the island of Askoey.

Vigander says the patient who died Wednesday also had “a very serious underlying” health disorder and an autopsy will be performed to determine “the ultimate cause of death.”

A 1-year-old child from the island died last week of an infection in the digestive tract, but it was not clear whether the death was linked to the water contamination.

About 2,000 people have fallen sick. Since June 6, 64 have been hospitalized.

Hospital tests have shown that Campylobacter was found in at least three dozen cases.

Local newspaper Askoeyvaeringen reported that there had been been safety issues with the waterworks in the Askoey municipality, and feces was recently found near a reservoir that supplied part of the area’s drinking water.

Cryptosporidiosis in Norway associated with self-pressed apple juice

In the autumn of 2018, an outbreak of cryptosporidiosis affected adult employees from the same company in Western Norway. The organism was Cryptosporidium parvum, GP60 subtype IIaA14G1R1.

All those infected had drunk from the same container of self-pressed apple juice. Incubation period (1 week) and clinical signs were similar among those infected, although some experienced a more prolonged duration of symptoms (up to 2–3 weeks) than others.

The infections resulted after consumption from only one of 40 containers of juice and not from any of the other containers. It seems that although Cryptosporidium oocysts were detected in a sample from another container, the contamination did not affect the whole batch. This is perhaps indicative of a restricted contamination event, either from contaminated ground in the orchard, or during collection of the fruit, or during processing.

Although outbreaks of foodborne cryptosporidiosis have previously been associated with consumption of contaminated apple juice, most of the more recent outbreaks of foodborne cryptosporidiosis have been associated with salad vegetables or herbs. This outbreak, the first outside U.S. reported to be associated with apple juice, is a timely reminder that such juice is a suitable transmission vehicle for Cryptosporidium oocysts, and that appropriate hygienic measures are essential in the production of such juice, including artisanal (non-commercial) production.

Robertson, L. J., Temesgen, T. T., Tysnes, K. R., & Eikås, J. E. (2019). An apple a day: An outbreak of cryptosporidiosis in Norway associated with self-pressed apple juice. Epidemiology and Infection, 147. doi:10.1017/s0950268819000232

http://www.bibme.org/bibliographies/228541420?new=true

Norway finds Salmonella outbreaks linked to countries visited

During summer 2016, Norway observed an increase in Salmonella enterica subsp. enterica serovar Chester cases among travellers to Greece.

Our aim was to investigate genetic relatedness of S. Chester for surveillance and outbreak detection by core genome multilocus sequence typing (cgMLST) and compare the results to genome mapping.

We included S. Chester isolates from 51 cases of salmonellosis between 2000 and 2016. Paired-end sequencing (2 × 250 bp) was performed on Illumina MiSeq. Genetic relatedness by cgMLST for Salmonellaenterica subsp. enterica, including 3,002 genes and seven housekeeping genes, was compared by reference genome mapping with CSI Phylogeny version 1.4 and conventional MLST.

Confirmed travel history was available for 80% of included cases, to Europe (n = 13), Asia (n = 12) and Africa (n = 16). Isolates were distributed into four phylogenetic clusters corresponding to geographical regions. Sequence type (ST) ST411 and a single-locus variant ST5260 (n = 17) were primarily acquired in southern Europe, ST1954 (n = 15) in Africa, ST343 (n = 11) and ST2063 (n = 8) primarily in Asia. Part of the European cluster was further divided into a Greek (n = 10) and a Cypriot (n = 4) cluster. All isolates in the African cluster displayed resistance to ≥ 1 class of antimicrobials, while resistance was rare in the other clusters.

Whole genome sequencing of S. Chester in Norway showed four geographically distinct clusters, with a possible outbreak occurring during summer 2016 related to Greece. We recommend public health institutes to implement cgMLST-based real-time Salmonella enterica surveillance for early and accurate detection of future outbreaks and further development of cluster cut-offs.

Whole genome sequencing of Salmonella Chester reveals geographically distinct clusters, Norway, 2000 to 2016

Siira Lotta, Naseer Umaer, Alfsnes Kristian, Hermansen Nils Olav, Lange Heidi, Brandal Lin T. Whole genome sequencing of Salmonella Chester reveals geographically distinct clusters, Norway, 2000 to 2016. Euro Surveill. 2019;24(4):pii=1800186. https://doi.org/10.2807/1560-7917.ES.2019.24.4.1800186

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2019.24.4.1800186#abstract_content

13 sick: Some had eaten rakfish: — more affected by mysterious listeria outbreaks in eastern Norway

News Beezer reports that shortly before Christmas, the Norwegian Institute of Public Health announced that there had been six reports of a new outbreak of Listeriosis. Today it was known that this number has increased significantly and that the affected area is also larger than previously known

Typically, 1-2 patients with listeriosis are reported monthly. Four of the six patients reported in December come from Hedmark and Oppland. Now the infection has spread further and is increasing more and more.

A total of thirteen people have been reported with listeriosis. Most are located in the above circles, and Buskerud is now included in the list. It is common that they are older than 70 years and affect their general condition. The Norwegian Food Safety Authority works with the Norwegian Institute of Public Health, the Municipal Health Service and the Norwegian Veterinary Institute to determine if patients can share a common source of infection. So far, five patients have detected bacteria with a similar DNA profile.

Norway reports increase in listeriosis

Outbreak News Today reports that officials with the Norwegian Institute of Public Health report seeing an increase in listeriosis cases in December, prompting a warning for high-risk groups.

According to an official notice Friday (computer translated), six cases were reported this month when the country typically sees 1-2 cases a month.

Four of the six patients reported in December are from Hedmark and Oppland.

Health officials are working to identify if their is a common food source linked to the increase in cases.

Listeria is usually transmitted through food, especially long-life foods that are refrigerated and eaten without further heat treatment. Many of these food products are popular as Christmas foods and can be found on many Christmas parties.

Over 20 affected by outbreak of stomach virus in Norway

The Norwegian Tourist Association (DNT) reported on Sunday that cases of a contagious stomach virus have broken out at some cabins at Hardangervidda. A total of 23 people were affected, reported the association

“It’s a hard problem when our people at our cabins get sick. We do our best to take care of them,” said Henning Hoff Wikborg, CEO of DNT Oslo and Omegn in a press release on Sunday.

Those who are ill have been isolated in their own room, and have access to their own toilet, or have been transported and accommodated in hotels, according to Wikborg.

 

Probably noro: Over 20 people affected by outbreak of stomach virus in Norway

The Norwegian Tourist Association (DNT) reported on Sunday that 23 people were affected by a stomach virus at Hardangervidda. The sick have been isolated from other patients.

The Norwegian Tourist Association (DNT) reported on Sunday that cases of a contagious stomach virus have broken out at some cabins at Hardangervidda. A total of 23 people were affected, reported the association

“It’s a hard problem when our people at our cabins get sick. We do our best to take care of them,” said Henning Hoff Wikborg, CEO of DNT Oslo and Omegn in a press release on Sunday.

Those who are ill have been isolated in their own room, and have access to their own toilet, or have been transported and accommodated in hotels, according to Wikborg.

Hordaland Red Cross have taken 15 people from Hardangervidda, and the municipality in Eidfjord fears an outbreak of ‘norovirus’, wrote Bergens Tidende newspaper on Sunday. Symptoms of the stomach virus are nausea, vomiting, abdominal pain and diarrhoea.

Two stricken with Giardia in Norway

Many thanks to our Norwegian correspondent who reports that two people admitted to Haukeland Hospital have been diagnosed with Giardia infection.

“We have two confirmed cases, but it is possibly a third too. It is too early to say anything about the source of infection,” says Surveillance Authority in Bergen municipality Kari Stidal Øystese.

Bergen is sensitive to Giardia outbreaks because in autumn 2004, the drinking water was infected by the Giardia parasite and approximately 5,000 people from Bergen became sick, and many have suffered after-effects for years.

In 2006, a SINTEF report commissioned drainage systems related to the buildings at Knatten, Starefossen and Tarlebøveien, triggered the epidemic. Local authority Torgeir Landvik would blame the dog owners for the fact that thousands of mountain people were infected by Giardia in the fall of 2004. But in 2015, an expert group picked up the dog-kit theory. “Based on available knowledge, Giardia infection from humans is still the most likely cause of the outbreak of disease and long-term strokes,” said the group’s conclusion.

A large community outbreak of waterborne giardiasis- delayed detection in a non-endemic urban area

BMC Public Health, 2006, 6:141,   Karin Nygård, Barbara Schimmer, Øystein Søbstad, Anna Walde, Ingvar Tveit, Nina Langeland, Trygve Hausken and Preben Aavitsland, https://doi.org/10.1186/1471-2458-6-141

https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-6-141

Background

Giardia is not endemic in Norway, and more than 90% of reported cases acquire the infection abroad. In late October 2004, an increase in laboratory confirmed cases of giardiasis was reported in the city of Bergen. An investigation was started to determine the source and extent of the outbreak in order to implement control measures.

Methods

Cases were identified through the laboratory conducting giardia diagnostics in the area. All laboratory-confirmed cases were mapped based on address of residence, and attack rates and relative risks were calculated for each water supply zone. A case control study was conducted among people living in the central area of Bergen using age- and sex matched controls randomly selected from the population register.

Results

The outbreak investigation showed that the outbreak started in late August and peaked in early October. A total of 1300 laboratory-confirmed cases were reported. Data from the Norwegian Prescription Database gave an estimate of 2500 cases treated for giardiasis probably linked to the outbreak. There was a predominance of women aged 20–29 years, with few children or elderly. The risk of infection for persons receiving water from the water supply serving Bergen city centre was significantly higher than for those receiving water from other supplies. Leaking sewage pipes combined with insufficient water treatment was the likely cause of the outbreak.

Conclusion

Late detection contributed to the large public health impact of this outbreak. Passive surveillance of laboratory-confirmed cases is not sufficient for timely detection of outbreaks with non-endemic infections.