Pulsenet prevents 276,000 foodborne illnesses a year

Posted on March 15, 2016 by Douglas Powell

An elderly woman in Phoenix. A Toledo toddler. An accountant in Indianapolis. All poisoned by food. Quickly uncovering that their illnesses are connected can make all the difference in halting a deadly
outbreak.

About 276,000 cases of foodborne illness are avoided each year because of PulseNet, a 20-year-old network coordinated by the Centers for Disease Control and Prevention, new research has found. PulseNet links U.S. public health laboratories so that they can speedily share details about E. coli, Salmonella and other bacterial illnesses.

The averted illnesses translate to $507 million in annual savings on medical bills and lost productivity, according to a study led by Robert L. Scharff of The Ohio State University and Craig Hedberg of the University of Minnesota.

PulseNet has created a climate that encourages better business practices and swift response to trouble, Scharff said, and that likely explains most of the avoided illnesses in the study.

In the face of public scrutiny, lawsuits and lost revenue, businesses have responded with better self-policing, he said.

“Companies are saying, ‘We can’t have this risk. This risk is too big for us,'” said Scharff, an associate professor of consumer sciences.

“What’s exciting for me is this shows the power of information in the market to force change on industry. It’s not just a way of tracking illness, but of allowing markets to work better.”

Scharff worked with experts from the CDC and elsewhere to assign a value to PulseNet, both in terms of illnesses prevented and dollars saved. The team analyzed data from 1994 to 2009.

The results, published in conjunction with PulseNet’s 20th anniversary, appear in the American Journal of Preventive Medicine.

PulseNet’s annual price tag is $7.3 million, according to the analysis. The network includes 83 state and federal laboratories where microbiologists uncover DNA fingerprints of illness-causing bacteria that tie cases together and confirm outbreaks.

“If more agencies used information as a tool instead of trying to fight the markets, I think we would all be better off,” said Scharff, also an economist who is part of Ohio State’s Food Innovation Center.

Tainted food is responsible for about 48 million illnesses, 128,000 hospitalizations and 3,000 deaths in the United States each year.

PulseNet’s purpose is to use DNA fingerprinting techniques to link illnesses that are likely to have a shared cause, even if the cases are widely dispersed. Food moves far and wide in the modern world and the first clues of an outbreak aren’t always clustered geographically.

Until now, health officials have not been able to assign a value to the service.

“PulseNet has been very impactful. We’ve known this for many years, but it’s been anecdotal. This gives us some hard figures,” said John Besser, deputy chief of the CDC’s enteric diseases laboratory branch.

PulseNet identifies about 1,750 clusters of disease a year, including nearly 250 that span multiple states.

“PulseNet is an integral part of our food-safety system and it helps improve the quality and safety of all the food that we eat,” said Besser, who formerly worked with PulseNet in Minnesota, one of the first states to embrace the program.

“Part of that effect is containing outbreaks, but a really significant portion of the benefit is giving feedback to the food industry and the regulatory agencies so they can make food safer,” he said.

Besser said he’s hopeful the federal government will be able to sustain PulseNet as changes in laboratory testing methods evolve. Placing a value on the service should help, he said.

To participate in PulseNet, state, county and city labs evaluate samples from people sickened by food and look for the DNA fingerprint of the bacteria, molecular subtyping that goes deeper than simply naming the responsible pathogen.

Salmonella cases, for example, arise all the time. And most are sporadic, meaning the strain of bacteria in one person’s stool sample isn’t likely to match the strain in the sample across town, or across the country. When they do match, there could be big trouble.

Scharff and his colleagues found that in states that put more DNA data into the system, the chance of future illnesses declined significantly.

Their work focused on E. coli, Listeria and Salmonella – the bacteria that have been analyzed by the network the longest. The team used two models. One was designed to capture indirect effects of PulseNet – the food contamination that never happened because the network exists.

This was possible because states have adopted PulseNet to differing degrees and at different times, opening the door for a calculation based on how rates of illness differ by PulseNet participation level.

“The more that a state uploads into the system, the lower reported illnesses will be,” Scharff said.

The second model estimated the direct effects of product recalls when outbreaks arise and are linked to a specific food. Faster identification of outbreaks, resulting in more timely recalls, led to 16,994 fewer Salmonella cases and 2,819 fewer E. coli cases a year at a savings of $37 million, the study found.

Though the study provides estimates of illness reduction, it’s unclear how many illnesses are being prevented because of improvements in fields, factories and slaughterhouses or how many are avoided due to better-informed government and consumer actions.

It is also impossible to know about spillover effects – reductions in foodborne illnesses from pathogens not included in this analysis.

“The calculations probably underestimate the impact of PulseNet,” Scharff said. “We did not examine whether illnesses from pathogens outside of the three in question were reduced as a result of industry efforts, though they likely were.”

The economic model also may not fully include all of the costs.

“We used a very conservative economic method of measuring health costs,” he said. The study did not assign a dollar value to losses from premature death and reduced quality of life, a number that could be quite large, the researchers wrote.

On the other side, “we aren’t able to estimate the cost to industry from remedial actions,” he said. “These could be significant for affected companies, but are lower than the costs of having foodborne illnesses associated with their products.”

The rise and fall of the American Salmonella empire

Posted on March 13, 2016 by Douglas Powell

Salmonella enterica causes an estimated 1 million domestically acquired foodborne illnesses annually. Salmonella enterica serovar Enteritidis (SE) is among the top three serovars of reported cases of Salmonella.

We examined trends in SE foodborne outbreaks from 1973 to 2009 using Joinpoint and Poisson regression. The annual number of SE outbreaks increased sharply in the 1970s and 1980s but declined significantly after 1990.

Over the study period, SE outbreaks were most frequently attributed to foods containing eggs. The average rate of SE outbreaks attributed to egg-containing foods reported by states began to decline significantly after 1990, and the proportion of SE outbreaks attributed to egg-containing foods began declining after 1997.

Our results suggest that interventions initiated in the 1990s to decrease SE contamination of shell eggs may have been integral to preventing SE outbreaks.

The rise and decline in Salmonella enterica serovar Enteritidis outbreaks attributed to egg-containing foods in the United States, 1973–2009

Epidemiology and Infection / Volume 144 / Issue 04 / March 2016, pp 810-819

P. Wright, L. Richardson, B. E. Mahon, R. Rothenberg, and D. J. Cole

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10170793&utm_source=Issue_Alert&utm_medium=RSS&utm_campaign=HYG

E. coli hitching a ride in healthy Japanese food handlers

Posted on March 11, 2016 by Douglas Powell

The actual state of intestinal long-term colonization by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in healthy Japanese people remains unclear. Therefore, a total of 4,314 fecal samples were collected from 2,563 food handlers from January 2010 to December 2011.

Approximately 0.1 g of each fecal sample was inoculated onto a MacConkey agar plate containing cefotaxime (1 μg/ml). The bacterial colonies that grew on each plate were checked for ESBL production by the double-disk synergy test, as recommended by the Clinical and Laboratory Standards Institute. The bacterial serotype, antimicrobial susceptibility, pulsotype, sequence type (ST), and ESBL genotype were checked, and the replicon types of plasmids harboring the ESBL gene were also determined after conjugation experiments.

ESBL producers were recovered from 70 (3.1%) of 2,230 participants who were checked only once. On the other hand, ESBL producers were isolated at least once from 52 (15.6%) of 333 participants who were checked more than twice, and 13 of the 52 participants carried ESBL producers for from more than 3 months to up to 2 years. Fluoroquinolone (FQ)-resistant E. coli strains harboring blaCTX-M were repeatedly recovered from 11 of the 13 carriers of blaCTX-M-harboring E. coli. A genetically related FQ-resistant E. coli O25b:H4-ST131 isolate harboring blaCTX-M-27 was recovered from 4 of the 13 carriers for more than 6 months. Three FQ-resistant E. coli O1:H6-ST648 isolates that harbored blaCTX-M-15 or blaCTX-M-14 were recovered from 3 carriers. Moreover, multiple CTX-M-14- or CTX-M-15-producing E. coli isolates with different serotypes were recovered from 2 respective carriers.

These findings predict a provable further spread of ESBL producers in both community and clinical settings.

Long-term colonization by blaCTX-M-harboring Escherichia coli in healthy Japanese people engaged in food handling

Applied and Environmental Microbiology; March 2016; vol. 82; no. 6; 1818-1827

Kunihiko Nakane, Kumiko Kawamura, Kensuke Goto and Yoshichika Arakawa

http://aem.asm.org/content/82/6/1818.abstract?etoc

Same as other nuts: Salmonella in pecans

Posted on March 7, 2016 by Douglas Powell

In-shell pecan samples (500 g) were collected over four harvest seasons (2010 to 2014) from seven pecan shelling facilities located in five U.S. states.

Four varieties of pecans were analyzed: Mexican Improved, Native Seedlings, Southern Improved, and Western Improved. Pecan samples (100 g) were sent to a third party laboratory for initial Salmonella screening. When a sample was positive for Salmonella, the pathogen level was determined by the most-probable-number (MPN) method (25, 2.5, and 0.25 g). Two sample preparation strategies were used for the MPN analysis, and both strategies were combined for the reported MPN values. Forty-four (0.95%) of 4,641 in-shell pecan samples were positive for Salmonella during initial screening; prevalence by year was 0.47 to 1.4%. Prevalence was not significantly different between varieties: Mexican Improved, 1.2%; Native/Seedling, 0.99%; Southern Improved, 0.97%; and Western Improved, 0.75%. Salmonella was not isolated from 31 of 44 samples upon retesting during MPN analysis (<0.47 MPN/100 g). When Salmonella was detected, the levels were 0.47 to 39 MPN/100 g, with a mean of 2.4 MPN/100 g. Thirty-one Salmonella serotypes were obtained from 42 Salmonella-positive pecan samples; Enteritidis was the most common (12% of samples) followed by Javiana (9%) and Braenderup (7%). All Salmonella Enteritidis isolates were phage type 8. Pulsed-field gel electrophoresis analysis (XbaI) revealed within-serotype diversity, indicating introduction of contamination from a variety of sources. Most (64%) of the isolates were resistant to streptomycin or tetracycline, and 13% were resistant to three or more antibiotics.

Salmonella prevalence and level on in-shell pecans is comparable to that on other nuts.

Prevalence, Level, and Types of Salmonella Isolated from North American In-Shell Pecans over Four Harvest Years

Journal of Food Protection, Number 3, March 2016, Pages 352-360, DOI: http://dx.doi.org/10.4315/0362-028X.JFP-15-365

K. Brar, L. K. Strawn, and M. D. Danyluk

http://www.ingentaconnect.com/content/iafp/jfp/2016/00000079/00000003/art00001

Salmonella in mince triggers Swedish supermarket recall

Posted on March 7, 2016 by Douglas Powell

Swedish supermarket ICA Group which has almost 2,000 stores across Sweden announced the recall of meat following salmonella threats.

If you’ve bought minced beef or pork from ICA range since February 28th you should not eat the produce. The supermarket chain has announced that 13 different products are affected by the scare. The batches of meat which are at risk of carrying salmonella are understood to have expiration dates of between March 6th and March 10th.

These include mince from ICA’s Basic and Import ranges which is sold in a variety of sizes and comes from Ireland, Sweden and Denmark. The company said in a statement that it had taken the meat off shelves across the country after discovering salmonella during a routine check.

Evidence of person-to-person transmission of Mycobacterium

Posted on March 5, 2016 by Douglas Powell

The U.S. Centers for Disease Control reports that Mycobacterium bovis, one of several mycobacteria of the M. tuberculosis complex, is a global zoonotic pathogen that primarily infects cattle. Humans become infected by consuming unpasteurized dairy products from infected cows (1,2); possible person-to-person airborne transmission has also been reported (3).

In April 2014, a man in Nebraska who was born in Mexico was determined to have extensive pulmonary tuberculosis (TB) caused by M. bovis after experiencing approximately 3 months of cough and fever. Four months later, a U.S.-born Hispanic girl from a nearby town who had been ill for 4–5 months was also determined to have pulmonary TB caused by M. bovis. The only social connection between the two patients was attendance at the same church, and no common dietary exposure was identified. Both patients had pulmonary cavities on radiography and acid-fast bacilli (AFB) on sputum-smear microscopy, indicators of being contagious (4). Whole-genome sequencing results of the isolates were nearly indistinguishable.

Initial examination of 181 contacts determined that 39 (22%) had latent infection: 10 (42%) of 24 who had close exposure to either patient, 28 (28%) of 100 who were exposed to one or both patients in church, and one (2%) of 57 exposed to the second patient at a school. Latent infection was diagnosed in six contacts on follow-up examination, 2 months after an initial negative test result (4), for an overall latent infection rate of 25%. No infected contacts recalled consuming unpasteurized dairy products, and none had active TB disease at the initial or secondary examination. Persons who have M. bovis TB should be asked about consumption of unpasteurized dairy products (2), and contact investigations should follow the same guidance as for M. tuberculosis TB (4).

Human M. bovis disease is typically attributed to consumption of unpasteurized milk (or dairy products made from unpasteurized milk) in or imported from countries with affected cattle herds (1,2,7,8). Person-to-person airborne transmission of M. bovis has been reported infrequently, with uncertainty remaining about dietary exposures (3). Findings from contact investigations and a population study regarding infectiousness of M. bovis compared with M. tuberculosis are inconclusive (4,9,10).††

Standard nucleic acid amplification test methods detect the M. tuberculosis complex without distinguishing between M. tuberculosis and M. bovis. Although these species can be distinguished by routine genotyping, biochemical characterization and drug susceptibility testing, which generally provide results earlier, have been historically used and can increase the index of suspicion for M. bovis. Whole-genome sequencing can be used to identify species and investigate transmission. NVSL sequences genomes for all U.S. M. bovis animal isolates, a convenience sample of cattle isolates from Mexico, and human isolates upon request.§§

Patient A might have been infected from consuming unpasteurized dairy products originating in Mexico. The timing of the illnesses, relatedness of the M. bovis isolates, and common church attendance suggest that patient B might have acquired infection from patient A. Findings from the contact investigations suggest possible airborne transmission, because approximately one third of the infections could not be explained by potential exposure in countries where M. tuberculosis complex infections are common. Consumption of imported contaminated dairy products could not be excluded, but locally produced dairy products were unlikely to be contaminated with M. bovis.

This report adds to the evidence for airborne person-to-person spread of M. bovis (3,9,10). Whole-genome sequencing is an emerging tool for investigating transmission. Public health responses to M. bovis pulmonary TB should be the same as those for M. tuberculosis TB, with additional inquiries about consumption of unpasteurized dairy products. The ongoing incidence of M. bovis TB in humans substantiates the need to control bovine tuberculosis globally and to pasteurize all milk and dairy products.

Possible airborne person-to-person transmission of Mycobacterium bovis- Nebraksa 2014

Centers for Diesease Control and Prevention Morbidity Weekly Report

Bryan F. Buss, DVM; Alison Keyser-Metobo, MPH; Julie Rother; Laura Holtz; Kristin Gall, MSN; John Jereb, MD; Caitlin N. Murphy, PhD; Peter C. Iwen, PhD; Suelee Robbe-Austerman, DVM; Melissa A. Holcomb, DVM; Pat Infield

http://www.cdc.gov/mmwr/volumes/65/wr/mm6508a1.htm?s_cid=mm6508a1_e

Women more at risk than men of developing HUS from STEC E. coli in Japan

Posted on March 5, 2016 by Douglas Powell

Shiga-toxin-producing Escherichia coli (STEC) infections usually cause hemolytic uremic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan.

A fatal case was used as a positive control in an outbreak of diarrheal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules.

To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005.

This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analyzed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.

Risk of hemolytic uremic syndrome caused by shiga-toxin-producing Escherichia coli infection in adult women in Japan

Epidemiology and Infection, Volume 144, Issue 5, April 2016, Pages 952-961, DOI: http://dx.doi.org/10.1017/S0950268815002289

Fujii, T. Mizoue, T. Kita, H. Kishimoto, K. Joh, Y. Nakada, S. Ugajin, Y. Naya, T. Nakamura, Y. Tada, N. Okabe, Y. Maruyama, K. Saitoh, and Y. Kurozawa

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10216096&utm_source=Issue_Alert&utm_medium=RSS&utm_campaign=HYG

Disney opens its food-safety secrets on Zebra devices

Posted on March 2, 2016 by Douglas Powell

It was the end of Sept. 2007 when I got an invite to check out behind-the-scenes food safety activities at several Disney World kitchens at the resort in Florida.

I was blown away.

The Chicago Tribune reports that now, a Chicago-area company will help bring the technology that Disney uses to keep its food safe to a variety of food-service providers.

Disney serves more than 81 million meals a year at its American theme parks and resorts, using custom software on a mobile device that can track milk from the point it’s collected from the cow to when it becomes a Mickey-shaped ice cream bar.

Disney and partners including Lincolnshire-based Zebra Technologies announced this week that its tools are available to anyone in the food-service industry.

High-profile food-safety fails like Chipotle’s have forced restaurants to snap to attention.

“I would say there’s definitely a growing demand,” said Pat Glennon, North American vice president of retail and hospitality for Zebra Technologies. “You’re taking it from pen-and-pencil record keeping to online, immediate tracking of food items from farm to fork, which is necessary as we move forward.”

Glennon said clients can use the software-hardware solution to better comply with food safety regulations.

Zebra Technologies provides the hardware, which runs software built by Baltimore-based iCertainty on Zebra’s Android mobile computers. Restaurant workers use temperature probes that connect wirelessly to the mobile devices to track food throughout the preparation process. They also use the installed Disney Chefs app to catalog details such as whether employees wash their hands frequently.

Disney uses almost 900 Zebra MC40 devices in more than 700 locations across the world, a Zebra spokeswoman said. She said Disney usually uses one device at each of its restaurant locations and is still ordering devices for a worldwide rollout. The Chefs app can run on any Android device, of which the Zebra MC40 is one option.

Disney is for the first time licensing the system it built more than six years ago with iCertainty to outside restaurants and chains, including Bloomin’ Brands, owner of Outback Steakhouse and Bonefish Grill, and Texas Roadhouse. Roy’s Chicago, at 720 N. State St., also is a customer, the Zebra spokeswoman said. Pricing varies based on client needs.

“Whether it’s food safety or ride safety, we’ve long been active in ways to enhance safety,” a Disney spokeswoman said. “We’re happy to share our best practices that can help others improve safety at their organizations.”

Not just cabbage and lettuce and cantaloupes: Listeria in produce

Posted on March 1, 2016 by Douglas Powell

Foodborne transmission of Listeria monocytogenes was first demonstrated through the investigation of the 1981 Maritime Provinces outbreak involving coleslaw.

In the following two decades, most listeriosis outbreaks involved foods of animal origin, e.g., deli meats, hot dogs, and soft cheeses. L. monocytogenes serotype 4b, especially epidemic clones I, II, and Ia, were frequently implicated in these outbreaks. However, since 2008 several outbreaks have been linked to diverse types of fresh produce: sprouts, celery, cantaloupe, stone fruit, and apples. The 2011 cantaloupe-associated outbreak was one of the deadliest foodborne outbreaks in recent U.S. history.

This review discusses produce-related outbreaks of listeriosis with a focus on special trends, unusual findings, and potential paradigm shifts. With the exception of sprouts, implicated produce types were novel, and outbreaks were one-time events. Several involved serotype 1/2a, and in the 2011 cantaloupe-associated outbreak, serotype 1/2b was for the first time conclusively linked to a common-source outbreak of invasive listeriosis. Also in this outbreak, for the first time multiple strains were implicated in a common-source outbreak.

In 2014, deployment of whole genome sequencing as part of outbreak investigation validated this technique as a pivotal tool for outbreak detection and speedy resolution. In spite of the unusual attributes of produce-related outbreaks, in all but one of the investigated cases (the possible exception being the coleslaw outbreak) contamination was traced to the same sources as those for outbreaks associated with other vehicles (e.g., deli meats), i.e., the processing environment and equipment. The public health impact of farm-level contamination remains uncharacterized.

This review highlights knowledge gaps regarding virulence and other potentially unique attributes of produce outbreak strains, the potential for novel fresh produce items to become unexpectedly implicated in outbreaks, and the key role of good control strategies in the processing environment.

Fresh produce–associated listeriosis outbreaks, sources of concern, teachable moments, and insights

Journal of Food Protection®, Number 2, February 2016, pp. 184-344, pp. 337-344(8)

Garner, Danisha; Kathariou, Sophia

http://www.ingentaconnect.com/content/iafp/jfp/2016/00000079/00000002/art00020

Does your state suck at food safety? CDC releases prevention status reports

Posted on March 1, 2016 by Douglas Powell

CDC has just released the latest Prevention Status Reports (PSRs), which highlight the status of state-level policies and practices to prevent or reduce problems affecting public health. The PSRs cover 10 public health topics—including food safety—and rate states on their implementation of recommended policies and practices.

The reports include a new measure on state adoption of selected provisions in the 2013 Food and Drug Administration (FDA) Food Code. The Food Code is a science-based model code that states can use to develop or update their food safety rules to better prevent foodborne illness and outbreaks.

CDC identified four Food Code provisions especially important in reducing outbreaks in restaurants and other retail food establishments:

exclude ill food service staff from working until at least 24 hours after symptoms, such as vomiting and diarrhea, have ended;
prohibit bare hand contact with ready-to-eat food;
require at least one employee in a food service establishment to be a certified food protection manager; and,
require food service employees to wash their hands.

The other two measures continue from the 2013 Prevention Status Reports. High scores for these two measures enable efficient detection and investigation of outbreaks:

speed of DNA fingerprinting using pulsed-field gel electrophoresis (PFGE) testing for all reported cases of Shiga toxin-producing E. coli O157; and,
completeness of PFGE testing of Salmonella.

The PSR website has been enhanced to include an interactive map that leads directly to topic reports for each state. The website also includes State Summary tables that outline the full set of policy and practice ratings for each state; a National Summary that gives aggregate ratings across states and rating comparisons for 2013 and 2015; the PSR Quick Start Guide; a fact sheet; answers to frequently asked questions; and a link to the 2013 PSRs.

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