Following an E. coli outbreak in 2006, when 17 people fell ill and one child died after eating mutton sausages in Norway, the meat industry introduced a number of measures in order to reduce the risk of food poisoning from meat.

Clean animals and good hygiene during slaughtering are essential preconditions for food safety.

Sigrun J. Hauge of the Norwegian School of Veterinary Science recently defended her doctoral research evaluating measures on farms and in slaughterhouses to reduce levels of dangerous E. coli.

Slaughterhouses have systems for categorizing animals according to how dirty they are. Around 3-5% of the animals that arrive at abattoirs are so soiled that they are categorized as high-risk. Every year, deductions in the price of meat due to dirty animals amount to over 9 million Norwegian kroners.

Soiled slaughter can pose a risk to food safety because feces on hides/wool, intestines, knives and the hands of the butchers can be transferred to the meat during the slaughter process. Hauge studied the factors affecting the cleanliness of animals on farms and how clean or soiled hide affects the contamination of skinned carcasses. Her experiments confirmed that meat from dirty cattle has more E. coli than meat from clean cattle.

Sheep farmers are also subjected to price reductions for dirty and unshorn animals. Hauge's research showed that the surface of meat from shorn sheep has less E. coli than that of unshorn sheep immediately after skinning and that the point in time that the sheep are shorn before slaughtering is also significant when it comes to the amount of bacteria immediately after skinning. But towards the end of the slaughtering process, all the meat had equal amounts of E. coli on its surface, regardless of when the sheep were shorn.

Dirty and unshorn animals are considered a high risk. They are treated in separate product streams in the slaughterhouses and their meat is not used for raw products such as minced meat and cured meat, but for products that are heat treated before sale (such as sausages and meatballs etc.).

Meat from lambs was hosed with water at 82 °C for 8 seconds in an enclosed "shower" - so-called hot water pasteurization -- before it was cooled. This treatment reduced the amount of E. coli on carcasses by 99.5%. After 5 days of cooling, no further E. coli were found on the meat. The recycled water in the shower was of a good microbiological, chemical and physical quality. Immediately after pasteurization, the meat was rather pale, but it regained its normal colour after being cooled for 24 hours.

Hot water pasteurisation is not generally accepted as a hygiene measure in Norway and the EU and the Norwegian Food Safety Authority would have to give its approval, if the method is to be used at slaughterhouses. Hot water pasteurization will obviate the need for separate product streams in abattoirs for high-risk sheep.

Cand.agric. Sigrun J. Hauge defended her doctoral research on 2nd May 2012 at The Norwegian School of Veterinary Science (NVH) with a thesis entitled “Hygienic impact of measures related to unclean cattle and sheep at farm level and in the abattoir.”

 Who knew?

The largest, most-fatal outbreak of E. coli O157 or other shiga-toxin producing E. coli wasn’t sprouts in Germany in 2011, wasn’t roast beef in Scotland in 1996 or Ontario in 1985, wasn’t Japan in 1996 in radish sprouts.

It was in Xuzhou, China, in 1999: 177 dead, 195 hospitalized with hemolytic uremic syndrome. An estimate of the number sickened was not available.

A new paper by Chinese researchers examining the E. coli O157:H7 virulence factors involved in the outbreak strain dryly notes, “A less well known massive outbreak of O157:H7 occurred in, China, in 1999 … which has only been reported in Chinese journals.”

Those extra languages could really come in handy.

The authors write in PLoS ONE today that,

“The O157:H7 outbreak occurred between April and September and peaked in June, 1999 with 195 HUS cases and 177 deaths from 52 villages of seven counties in Jiangsu and neighboring Anhui province. Of the 195 cases, 167 (85.6%) were over 50 years old with only two less than 20 years old and 121 (62.1%) were female. The National Institute for Communicable Disease Control and Prevention, China CDC, commenced the outbreak investigation on June 28, 1999.

“Three and two strains of O157:H7 were isolated in Xuzhou city from fecal screening of 30 HUS and 25 diarrhea patients respectively. Thirty six sera collected from 42 HUS patients (85.7%) tested positive for IgG against EHEC-hemolysin or O157 lipopolysaccharide. Thus both bacterial and serological data confirmed that the outbreak was caused by O157:H7. The source of the infection was investigated using a case-control sample of 146 HUS patients and 840 healthy individuals, matched in age, sex and residence. No hand-washing before eating, consumption of fruits or vegetables without washing, consumption of leftover foods without heating, no fly-net cover for foods and high density of flies in kitchen were found to be statistically associated with infected patients. Using magnetic beads coated with antibodies against the O antigen, O157:H7 was isolated from six of 67 (9.0%) fly specimens, four of 74 (5.4%) raw meats and three of 83 (3.6%) cooked meats. O157:H7 was also isolated from live animals including 32 of 189 (16.9%) cattle, 50 of 605 (8.3%) pigs, 91 of 590 (15.4%) goats and 52 of 604 (8.6%) chickens raised in courtyards of families with and without HUS patients in the same villages.

“From the epidemiological investigations, the outbreak was mainly associated with peasants living with animals carrying O157:H7 in the household, including goats, pigs, chickens and cattle. Courtyard animals carrying O157:H7 contaminated the surrounding environment through fecal shedding and persons who had poor personal and kitchen hygiene practice were more likely to be infected. It is well established that farm animals are carriers of O157:H7. Additionally we found that 9% of the flies tested were positive for O157:H7 and thus they are important carriers in this outbreak. Flies may not just be mechanical vectors as O157:H7 can multiply inside the fly's mouth and be excreted through fly fecal matter. Therefore poor hygiene and multiple routes of transmission may be the major contributing factors to the massive outbreak. However, increased transmission would have expected to increase number of infections but not higher number of HUS rate and high mortality rate. Host factors may contribute to higher mortality with a disproportional number of HUS cases and deaths in the older age groups. We showed that the outbreak was caused by a new sequence type, ST96.”

Abstract below:

A novel Escherichia coli O157:H7 clone causing a major hemolytic uremic syndrome outbreak in China***
30.apr.12
PLoS ONE 7(4): e36144.
Yanwen Xiong, Ping Wang, Ruiting Lan, Changyun Ye, Hua Wang, Jun Ren, Huaiqi Jing, Yiting Wang, Zhemin Zhou, Xuemei Bai, Zhigang Cui, Xia Luo, Ailan Zhao, Yan Wang, Shaomin Zhang, Hui Sun,Lei Wang, Jianguo Xu
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0036144
An Escherichia coli O157:H7 outbreak in China in 1999 caused 177 deaths due to hemolytic uremic syndrome. Sixteen outbreak associated isolates were found to belong to a new clone, sequence type 96 (ST96), based on multilocus sequence typing of 15 housekeeping genes. Whole genome sequencing of an outbreak isolate, Xuzhou21, showed that the isolate is phylogenetically closely related to the Japan 1996 outbreak isolate Sakai, both of which share the most recent common ancestor with the US outbreak isolate EDL933. The levels of IL-6 and IL-8 of peripheral blood mononuclear cells induced by Xuzhou21 and Sakai were significantly higher than that induced by EDL933. Xuzhou21 also induced a significantly higher level of IL-8 than Sakai while both induced similar levels of IL-6. The expression level of Shiga toxin 2 in Xuzhou21 induced by mitomycin C was 68.6 times of that under non-inducing conditions, twice of that induced in Sakai (32.7 times) and 15 times higher than that induced in EDL933 (4.5 times). Our study shows that ST96 is a novel clone and provided significant new insights into the evolution of virulence of E. coli O157:H7.

The Food Safety Authority of Ireland has urged childcare workers and crèche owners to ensure they have robust hygiene practices in place to reduce the incidence of E coli.

The authority has said it is concerned at the high levels of E coli infection here, with 285 cases of human infection provisionally recorded last year.

There were nine outbreaks in children attending crèches, or who were cared for in the home by childminders.

This involved some 75 children and adults becoming ill, with seven being hospitalised last year.

The FSAI says young children and infants are particularly at risk from E coli infection, and children and workers in childcare settings can unwittingly spread infection.

Washing hands is the single most important way to stop the spread of these E coli. Young children should be helped to wash and dry their hands. Babies need to have their hands washed as often as older children.

As well as handwashing, infection can be prevented by using a safe water supply and preparing food hygenically.

Staff are asked to stay away from childcare facilities for 48 hours if they have had diarrhoea or vomiting, and they should contact the Department of Public Health for advice to prevent more cases.

The FSAI has just published a leaflet - How to Protect the Children in Your Care - which is freely available on www.fsai.ie.

The Columbia Tribune reports a Boone County, Missouri, 2-year-old infected with E. coli remained hospitalized this morning in Columbia as one of five Central Missouri residents battling the bacteria.

Geni Alexander, public information officer for the Columbia/Boone County Department of Public Health and Human Services, said the 2-year-old is one of three Boone County residents with either a confirmed or suspected case of the illness.

Alexander said health officials have determined that consumption of raw dairy products was the only common link for possible exposure among the three Boone County victims. She did not disclose the gender of the victims.

"Each person was identified as a raw dairy consumer," Alexander said, "but we can't say they all got it from the same place."

The Missouri Department of Health and Senior Services is investigating an increase in cases of Shiga toxin-producing E. coli in Central Missouri from late March through early April. In addition to the Boone County 2-year-old, state health officials reported Thursday that a 17-month-old toddler also developed symptoms of hemolytic uremic syndrome, or HUS, a severe condition that can lead to permanent kidney damage in some who survive the illness.

Alexander said the victims of the three Boone County cases range in age from 2 to 31. The 17-month-old victim is not a Boone County resident, she said.

"In public health, we always advise to stay away from those raw dairy products," she said.

A table of raw milk related outbreaks is available at http://bites.ksu.edu/rawmilk.