Tracing back to the farm: E. coli O157 from 2007 still going

Jim Romahn writes that beef producers should watch an unfolding court battle dating back to a 2007 E. coli O157 outbreak in the U.S. because it’s becoming clear that they could be in for huge legal costs if suppliers can prove their cattle came to market carrying food-poisoning bacteria.

forensic DNAThis could be particularly true if the producers failed to use a vaccine that is available to reduce the shedding of harmful bacteria. A recent survey found that only two per cent of producers use the vaccine.

Romahn explains that Cargill Meat Solutions successfully sued Greater Omaha Packing Ltd. for $9 million over E. coli contamination of its ground beef, but now Greater Omaha is petitioning an appeal court to hear the case again.

Henry Davis, president and owner of Greater Omaha Packing Ltd., says his company tested every shipment of beef trimmings to Cargill and did not find any E. coli O157:H7.

Omaha was also not Cargill’s only supplier.

But when Cargill filed suit in 2011, it said it was able to identify Greater Omaha Packing Ltd. as the source of the E. coli contamination that led to a huge product recall. It sought about $25 million.

“Greater Omaha’s position is simply that you cannot mix its raw materials that tested negative for E. coli O157:H7 with other suppliers’ raw materials that have never been tested for E. coli O157:H7 or used a different testing protocol and then blame Greater Omaha when the end product is contaminated with E. coli O157:H7,” said Davis.

The case revolves around hamburger produced at Cargill over two days in August 2007. 

Greater Omaha argues while both days’ production had the same E. coli O157:H7 link, Cargill used Greater Omaha’s raw materials in only one of those days’ production while two other raw material suppliers were used both days. 

One of those suppliers was located overseas and never tested for E. coli O157:H7, according to Davis. 

Water and friends

I sometimes retweet my friend Jim Fischer’s accounts of his new ventures as a maple syrup producer (Canadian, eh), B&B entrepreneur, forest management dude, and high school supply teacher.

braunwynn.kittens.03He’s lived a rich life, and will continue. Look at his mother (below, left), 92-years-old and pulling the last syrup off this year’s batch, yesterday.

But when I think of Jim, it’s not his passion for agriculture, his family, or how he always terrified my girls when he delivered chickens by telling them that any cats on his dairy farm would be shot, instantly, to reduce the risk of disease (in fairness, Jim did arrange for us to adopt 3 kittens from the Walkerton animal shelter).

When I think of Jim, it’s how he handled the outbreak of E. coli O157 in Walkerton, Ontario in 2000 that killed seven and sickened 2,500 in a town of 5,000.

“Whenever we heard a helicopter, it probably meant someone else had died.”

That outbreak took a huge toll, in numbers, and in personal memories.

Water, so essential, so precious.

Water safety is vital, and the quality of water important in terms of public health. One of the objectives of the Water Quality and Health Strategy of the World Health Organization (WHO) for the 2013 to 2020 period, is to obtain ‘the most rigorous and relevant evidence regarding water quality and health’ [1].

In terms of infectious diseases, water can transport pathogens in the environment through different steps of the water cycle [2,3]. In the water, some physical or chemical parameters, e.g. temperature, pH, salinity, organic matter, may affect the survival of the pathogens [4]. Substances intended to control pathogens or insects (antimicrobials,  antivirals and pesticides) can occur in water subsequent to their use [5,6] or manufacturing process [7,8]. This may paradoxically induce pathogen or vector resistance to these substances [9-12]. Moreover, water can also bear a number of pathogens with resistance acquired through other pathways [13]. Exposure of people to waterborne pathogens may occur by drinking or swallowing water, inhaling aerosolised droplets and contact with water through bathing and recreation [14,15]. Some pathogens may also be disseminated by water further in the environment (e.g. in the soil and air) potentially allowing human exposure. Consuming foods, grown on/in or irrigated with pathogen-contaminated water may also lead to infection [16,17].

fischer.syrup.apr.16As a number of changes to water, e.g. canalisation, temperature, nutrient enrichment, addition of pest-control or antimicrobial/viral substances, and pathogen contamination, result from human activities, it is relevant to understand their impact on infectious disease epidemiology. To provide some examples relevant for European public health, and to present issues related to the detection and identification of cases of waterborne outbreaks and the proof of anthropogenic change to water as the cause, we issued a call for papers [18]. Subsequent to this, we now publish five articles, through which a number of issues arise and which can be summarised as follows.

The challenges of outbreaks potentially caused by microbial contamination of water are first illustrated in a report from Italy, where an outbreak of monophasic Salmonella Typhimurium 1,4 [5],12:i:- with sole resistance to nalidixic acid is described [19]. Attempts to determine the source of this outbreak led to extensive environmental investigations. While its cause could not be ascertained, a number of surface water samples in the outbreak area, including of water used for growing fruit and vegetables, were positive for the outbreak strain. Moreover some water samples from local sewage treatment plants also tested positive, thus leading to the hypothesis that wastewater may have contaminated irrigation water [19]. The epidemiological investigation was complicated and the origin of the outbreak strain and how this strain acquired its resistance to nalidixic acid remain unresolved. The study reinforces the value of detecting waterborne outbreaks early.

Generally, water may become contaminated from a non-point source, such as the runoff of water from manure in agricultural fields, or from a point discharge, such as a hospital wastewater outlet or a sewage treatment plant. The issue of clinical wastewater harbouring microorganisms resistant to antimicrobials, and its subsequent effect on sewage and freshwater is important for public health, particularly if resistant bacteria introduced in the water can not only survive but also grow in wastewater. Acinetobacter baumanni for example, is considered a nosocomial pathogen, but its ecology is as of yet not fully understood and the observation of community outbreaks has made environmental niches suspect. A study from Croatia finds multiresistant A. baumannii strains in both influent and effluent water to a sewage treatment plant in Zagreb, indicating that such strains can evade the treatment process. The study shows moreover that isolated strains can survive and grow in effluent sewage water up to 50 days, posing a potential risk for further dissemination in the recipient river to the plant [20].

As a risk exists for surface water to become contaminated by wastewater pathogens, there is relevance in fully assessing its safety for further human use. A study from Serbia conducted during the bathing season reveals adenovirus and rotavirus genetic materials in recreational waters of the Danube, along popular public beaches in addition to faecal contamination. As the presence of viruses could not necessarily be predicted by the amount of bacteria measured in the water via routine quality control, the authors conclude that viral indicators may be helpful for further assessing the risks posed by water, in particular in areas where the sewer network is insufficient or inadequate [21].

walkertonWhich panels of viruses could serve as relevant indicators of water quality in certain circumstances would need further investigations, as this may depend in part on their infectivity doses and persistence in environmental water. Also this might require to know what potential viruses contaminate the water to begin with, possibly first requiring agnostic screening techniques. In this regard, the development and implementation of assays that can be used for the surveillance of the whole population of viruses in water samples can be of interest. In this special issue, a methodology combining tangential flow filtration of sewage combined with deep sequencing, without the need for cell culture, is presented as an agnostic approach to survey viruses in sewage. The use of this methodology is proposed for the surveillance of poliovirus, but broader applications, including creating new viral sequence databases for retrospective analysis of presently unknown human viruses that may be discovered in the future are suggested [22].

Should it be a priori known what viruses likely contaminate water in an area, defining more specific tools to confirm their presence may be considered. Moreover in terms of further risk assessment, and as also discussed in the Serbian study in this issue [21], assays to determine the presence of infectious virus might also be of value.

As illustrated by some of the above studies [19,21], adequate management of wastewater is crucial. Indeed, water contaminated by wastewater can subsequently cumulate in larger water bodies such as lakes or the ocean. There, its impact may be less clear, as not only pathogens, but supportive nutrients may be carried by the wastewater. In combination with meteorological factors such as temperature, this may lead to the sporadic or intermittent occurrence of ‘exotic’ or ‘unusual’ pathogens in some areas [4]. An article from the Netherlands describes three cases of Vibrio cholera non-O1 serogroup (VCNO) bacteraemia reported in the country. Cases had been prior exposed to fish and/or had contact with surface water. The Dutch study includes a review of the literature to identify sources and risk factors for bacteraemia [23].

In conclusion, this special issue provides some insights into the importance of surveillance of pathogens in the water [19-23] and outbreaks or cases caused by waterborne pathogens [19,21,23]. Wider studies could help further refine criteria for assessing water treatment processes. Through pollution of ground water with antimicrobials and multi-resistant bacteria, waterborne outbreaks of multi-resistant bacteria are likely to become more frequent in the future. The special issue illustrates that addressing the problems due to anthropogenic changes to water on the epidemiology of human pathogens will require a multi-disciplinary approach.

A note from the editors: impact of anthropogenic changes to water on human pathogens

Eurosurveillance, Volume 21, Issue 15, 14 April 2016

Don’t eat poop, and if you do, cook it: Manure application research aims to improve food safety

New field research out of Clarkson University in upstate New York is attempting to answer how likely microbes can travel from manure application sites to downwind produce.

lettuce.skull.noroShane Rogers, an associate professor of civil and environmental engineering, led a research team that looked into the issue. They measured how far common bacteria, including Salmonella and E. coli, are likely to travel downwind from manure application sites. They hoped to better understand how fresh produce might be contaminated by nearby animal agriculture practices.

“Our goal was to provide a logical framework to study this pathway,” Rogers said. This helped them make science-based recommendations for setback distances that protect human health.

The team used field data to understand how these bacteria travel from manure application sites to produce. The research lasted three years. They took samples at several distances from manure application sites and measured the presence of illness-causing bacteria.

The researchers used computer models to expand their understanding. “It is not possible to obtain measurements for every possible set of circumstances that may exist,” Rogers said. “The models allow us to predict produce contamination over a larger range of probable conditions than our raw measurements would provide.” These include the type of manure, the terrain of the farm, and weather conditions at the time the manure is applied.

The team also evaluated the risk of illness. This gave the team a better understanding of how likely someone is to get sick from produce when a certain amount of bacteria is present.

Combining all that data, the team found that produce fields should be set back from areas of manure application by at least 160 meters. That distance should help lower the risk of foodborne illness to acceptable levels (1 in 10,000).

Rogers emphasized that the advice is for a minimum setback. “(160 meteårs is) the minimum distance that produce growers should maintain between manure application activities and produce growing areas,” Rogers said. Additional distance and delay between manure application and harvest would provide further protection.


3 kids dead, 22 sick in Europe Shiga toxin-producing E. coli outbreak linked to dairy

A multi-country outbreak of Shiga toxin-producing Escherichia coli (STEC) infection associated with hemolytic uremic syndrome (HUS) and affecting mostly young children has been reported in the last two months in Romania.bobby.crosier.e.coli.sep.15

Italy reported one related HUS case through the Early Warning and Response System (EWRS) on 21 March 2016.

Overall, 25 cases were identified as associated with this outbreak, of which 19 developed HUS and three died. Twelve cases had microbiological and/or serological evidence of STEC O26 infection; 13 additional cases met the probable case definition by developing HUS, testing positive for another STEC O serogroup (O157) or by testing positive by PCR for stx1 and/or stx2 and eae genes.

Information collected from patients pointed towards a milk processing establishment (the Romanian operator) as a possible source of infection. The implicated milk processing establishment exported a particular type of cheese to four EU countries (Belgium, Germany, Italy and Spain) and one Italian importer further distributed this product to France and Germany. In Romania, one fresh cheese product made of cow’s milk produced by the Romanian operator tested positive for E. coli O26 not possessing stx virulence genes. Other dairy products produced by the Romanian operator tested positive for E. coli virulence genes stx1, stx2 and eae. In Italy, a STEC O26 strain (positive for stx1, stx2 and eae) was isolated from a sample of the cheese that had been produced by the Romanian operator, imported from Romania and consumed by the Italian child that later developed HUS (stool samples negative for STEC but serum samples positive for the presence of antibodies against the LPS of E. coli O26). The PFGE analysis suggests the potential involvement of multiple strains from a common source or from multiple sources. Multi-strain STEC outbreaks have been reported in the past [1]. Therefore, it cannot be excluded that the cases belong to a single outbreak associated with a source contaminated by different strains.

The epidemiological evidence linking some of the Romanian cases and the Italian case to the Romanian operator, in addition to the microbiological findings, are consistent with the hypothesis of a multi-strain outbreak. The last Romanian case associated with this outbreak had onset of symptoms on 14 March. The cheese consumed by the Italian case was imported in Italy from Romania on 1 March and had been produced on 18 February 2016 with an expiry date of 18 April 2016. A recall of the company products was undertaken in Romania as of 5 March and in Italy as of 15 March. Other Member States subsequently undertook recalls. According to information available at the time of conducting this assessment, the withdrawal of potentially contaminated dairy products following a recall has been limited in Member States, with the exception of Romania. It is therefore possible that affected products are still present in households, and detection of new cases cannot be excluded. In order to minimise the spread of the infection and investigate possible new cases in a timely manner, Romania, Italy and other Member States that are possibly involved could consider enhancing surveillance for HUS and STEC cases. Continued enhanced surveillance for HUS in children on a routine basis in Romania could provide further early warning of ongoing or new contamination events. The questionnaire used to interview some of the Romanian cases and the Italian case is available in English from ECDC upon request. If new cases are identified, these should be reported to the Epidemic Intelligence Information System for food- and waterborne diseases (EPIS-FWD). In such situations public health authorities could also consider conducting an epidemiological analytical study and including further food and environmental sampling in suspect premises to identify the vehicle of Multi-country outbreak of infection. Whole genome sequencing (WGS) on isolates detected so far should be carried out to provide more detailed information about possible links between cases. The investigation of the European dimension of this cross-border foodborne outbreak has demonstrated the added value of collaboration between Romanian and Italian public health and food authorities as well as ECDC and EFSA in enabling appropriate risk assessment and response.


Sheep go to heaven, goats go to hell: 41 sick as E. coli at Connecticut petting farm grows

More cases of E. coli have now been confirmed in connection to a dairy farm in Lebanon.

959978c3eb4288a90f1a4f44403753c2The Department of Public Health now says that 41 people have been diagnosed with E. coli after visiting the Oak Leaf Dairy Farm in March. The patients range in age from 9 months to 45 years old, with a median age of five. Of the 41 patients, seven are adults and the other 34 are under the age of 18. Of those under 18, 22 are under the age of five.

Of those who were diagnosed with E. coli, 10 were hospitalized, and one remains in the hospital. Also, three of the hospitalized patients were also determined to have hemolytic uremic syndrome, a rare but serious illness that affects the kidneys and blood clotting. The one child still hospitalized is one of the three who had HUS.

A table of animal contact-linked outbreaks can be found here.

Seek and ye shall find: Shiga-toxin E. coli and sick people in Michigan

Infection with Shiga toxin-producing Escherichia coli (STEC) by serotypes other than O157 (non-O157) have been increasingly reported in the United States. This increase in reporting is primarily due to the improvements in diagnostic tests. analysed 1,497 STEC cases reported in Michigan from 2001 to 2012. A significant increase in the number of non-O157 STEC cases was observed over time, and similar incidence rates were observed for O157 and non-O157 STEC cases in certain time periods.

The odds of hospitalization was two times higher in O157 STEC cases relative to non-O157 STEC cases when adjusted for age and gender, suggesting that O157 STEC causes more severe clinical outcomes in all age groups.

The use of population-based surveillance to better define trends and associations with disease severity are critical to enhance our understanding of STEC infections and improve upon current prevention and control efforts.

Increasing incidence of non-O157 Shiga toxin-producing Escherichia coli (STEC) in Michigan and association with clinical illness

Epidemiology and Infection / Volume 144 / Issue 07 / May 2016, pp 1394-1405

Road less traveled: Shiga-toxin E. coli cluster on farms and among farms separated by roads

The aim of this study was to examine the population structure, transmission and spatial relationship between genotypes of Shiga toxin-producing Escherichia coli (STEC) and Campylobacter jejuni, on 20 dairy farms in a defined catchment.

road-less-traveledPooled faecal samples (n = 72) obtained from 288 calves were analysed by real-time polymerase chain reaction (rtPCR) for E. coli serotypes O26, O103, O111, O145 and O157. The number of samples positive for E. coli O26 (30/72) was high compared to E. coli O103 (7/72), O145 (3/72), O157 (2/72) and O111 (0/72). Eighteen E. coli O26 and 53 C. jejuni isolates were recovered from samples by bacterial culture. E. coli O26 and C. jejuni isolates were genotyped using pulsed-field gel electrophoresis and multilocus sequence typing, respectively.

All E. coli O26 isolates could be divided into four clusters and the results indicated that E. coli O26 isolates recovered from calves on the same farm were more similar than isolates recovered from different farms in the catchment. There were 11 different sequence types of C. jejuni isolated from the cattle and 22 from water.

An analysis of the population structure of C. jejuni isolated from cattle provided evidence of clustering of genotypes within farms, and among groups of farms separated by road boundaries.

Diversity and relatedness of Shiga toxin-producing Escherichia coli and Campylobacter jejuni between farms in a dairy catchment

Epidemiology and Infection / Volume 144 / Issue 07 / May 2016, pp 1406-1417

Tragic: Japanese woman dies of sequela of E. coli poisoning 20 yrs after infection

In June 1996, initial reports of an outbreak of E. coli O157:H7 in Japan surfaced in national media.

radish_sproutsBy July 1996, focus had centered on specific school cafeterias and two vendors of box lunches, as the number of illnesses approached 4,000. Lunches of sea eel sushi and soup distributed on July 5 from Sakai’s central school lunch depot were identified by health authorities as a possible source of one outbreak. The next day, the number of illnesses had increased to 7,400 even as reports of Japanese fastidiousness intensified. By July 23, 1996, 8,500 were listed as ill.

Even though radish sprouts were ultimately implicated — and then publicly cleared in a fall-on-sword ceremony, but not by the U.S. — the Health and Welfare Ministry announced that Japan’s 333 slaughterhouses must adopt a quality control program modeled on U.S. safety procedures, requiring companies to keep records so the source of any tainted food could be quickly identified.

Kunio Morita, chief of the ministry’s veterinary sanitation division was quoted as saying “It’s high time for Japan to follow the international trend in sanitation management standards.”

Japanese health authorities were tragically slow to respond to the outbreak of E. coli O157:H7, a standard facilitated by a journalistic culture of aversion rather than adversarial. In all, over 9,500 Japanese, largely schoolchildren, were stricken with E. coli O157:H7 and 12 were killed over the summer of 1996, raising questions of political accountability.

The national Mainichi newspaper demanded in an editorial on July 31, 1996, “Why can’t the government learn from past experience? Why were they slow to react to the outbreak? Why can’t they take broader measures?” The answer, it said, was a “chronic ailment” — the absence of anyone in the government to take charge in a crisis and ensure a coordinated response. An editorial cartoon in the daily Asahi Evening News showed a health worker wearing the label “government emergency response” riding to the rescue on a snail. Some of the victims filed lawsuits against Japanese authorities, a move previously unheard of in the Japanese culture of deference.

Today, the sad news arrived that a 25-year-old woman in Sakai, Osaka Prefecture, died in last October of an aftereffect of her infection with E. coli O157 in 1996.

radish.sprouts.2The woman had been suffering renal vascular hypertension, a sequela of hemolytic-uremic syndrome she developed upon her infection with O-157 when she was a first-grade student, the city government said, adding the direct cause of her death was brain bleeding due to the hypertension.

Sakai Mayor Osami Takeyama said in a comment that the city will redouble efforts for safety control and crisis management.
 The municipal government now plans to provide compensation for the family of the woman.

The current version of events in July 1996, according to the Japanese, was 9,523 sick, including 7,892 elementary school children, in Sakai who ate school lunch or other food were infected with the E. coli bacteria. In the massive outbreak, three girls died.


STEC E. coli and biofilm production

The objectives of this study were to characterize the phenotype and genotype of 36 non-O157 Shiga toxin–producing Escherichia coli (STEC) strains isolated from humans, ovines, or bovines, including the top 6 (O26, O45, O103, O111, O121, and O145) and three other serogroups implicated in serious illness (O91, O113, and O128).

e,coli.biofilmBiofilms were formed by all strains with intermediate to strong biofilm producers (n = 24) more common at 22°C than at 37°C (p < 0.001) and 48 and 72 h (p < 0.001) than 24 h of incubation time. Biofilm-forming potential differed by serogroup and origin with O113 and human strains exhibiting the highest potential (p < 0.001). Biofilm-associated genes, csgA/csgD/crl/fimH (100%), flu (94%), rpoS (92%), ehaAα (89%), and cah (72%), were most prevalent, while mlrA (22%) and ehaAβ (14%) were least prevalent, although there was no clear compliment of genes associated with strains exhibiting the greatest biofilm-forming capacity.

Among 12 virulence genes screened, iha and ehxA were present in 92% of the strains. The occurrence of stx1 in the top 6 serogroups (8/12, 67%) did not differ (p = 0.8) from other serogroups (17/24, 71%), but stx2 was less likely (confidence interval [CI] = 0.14–1.12; p = 0.04) to be in the former (9/24, 38%) than the latter (9/12, 75%). Excluding serogroups, O91 and O121, at least one strain per serogroup was resistant to between three and six antimicrobials. Streptomycin (31%), sulfisoxazole (31%), and tetracycline (25%) resistance was most common and was 35–50% less likely (p < 0.05) in human than animal strains.

All non-O157 STEC strains were able to form biofilms on an abiotic surface, with some exhibiting resistance to multiple antimicrobials. Potential as a reservoir of antimicrobial resistance genes may be another hazard of biofilms in food-processing plants. As a result, future strategies to control these pathogens may include measures to prevent biofilms.

Biofilm formation, virulence gene profiles, and antimicrobial resistance of nine serogroups of non-O157 shiga toxin-producing E. coli

Wang, K. Stanford, T.A. McAllister, R.P. Johnson, J. Chen, H. Hou, G. Zhang, and Y.D. Niu

Foodborne Pathogens and Disease, Volume 13, Number 6, March 2016, Pages 1-9, DOI: 10.1089/fpd.2015.2099


Aus/NZ health types stand strong for safe milk

A campaign to legalize raw cow’s milk has found Far North Queensland support but health authorities have warned it is unfit for human consumption.

colbert.raw.milkTablelands dairy farmers have been drinking milk straight from the vat all their lives and believe the unpasteurised product could be safely sold to the public if regulated properly.

Chief Health Officer Dr Jeannette Young has warned raw milk isn’t fit for human consumption.

“People who consume ­unpasteurized milk are at ­increased risk of infection due to dangerous bacteria such as salmonella, E. coli and listeria, which are capable of causing severe illness and potentially death,” she said.

“All unpasteurised milk products in Australia are ­required to be labelled with a statement to the effect that the product has not been pasteurized and is not for human ­consumption.”

Raw milk is sold as bath milk at health stores such as The Healthy Hub in Cairns, where a two-litre bottle fetches $11.50.

Meanwhile, New Zealand food safety minister Jo Goodhew is making no apologies for tough new regulations for raw milk producers.

Mrs. Goodhew said new rules simply brought the milk into line with other products being sold to the public for consumption, and aimed to keep people safe.

“It does only put these producers on a par with other food producers who sell high-risk products such as, for instance, shellfish.”