Radioactive Microspheres Match Embolization for Liver Cancer

Daniel M. Keller, PhD

May 10, 2013

AMSTERDAM, the Netherlands — For patients with unresectable intermediate-stage hepatocellular carcinoma, selective internal radioembolization and standard transarterial chemoembolization provide equivalent outcomes, new research shows. The advantage of radioembolization is that it can be administered in a single treatment.

"Our small pilot study suggests that a single session of radioembolization is as safe and effective as multiple sessions of chemoembolization. There are no differences between radioembolization and chemoembolization in terms of health-related quality of life, progression-free survival, or severity of adverse events," said Frank Kolligs, MD, from the University of Munich in Germany.

Dr. Kolligs presented the study results here at the International Liver Congress 2013.

Although both approaches can result in downstaging of the disease, possibly allowing for curative surgery or transplantation, chemoembolization is considered the treatment of choice for inoperable intermediate-stage hepatocellular carcinoma in guidelines from the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases. However, chemoembolization is often associated with postembolization syndrome.

Dr. Kolligs and his team conducted an open-label, randomized, prospective study of 28 evaluable patients from 2 university centers. This sample size allowed them to compare the different approaches for health-related quality of life.

They screened patients with liver angiography and then randomized them to radioembolization or chemoembolization. Study participants were 18 years or older, had a performance status of 0 or 1, Child–Pugh class B-7 cirrhosis or lower, and a bilirubin level of 2 mg/dL or less. Exclusion criteria were previous chemoembolization treatment, extrahepatic disease or portal vein occlusion, more than 5 lesions, any lesion 10 cm or larger, a cumulative lesion diameter of 20 cm or larger, and anticipated liver resection or transplantation.

At baseline, 85% of participants were men, mean age was 65.6 years, and time since diagnosis ranged from 0.8 to 1.1 months. Most had a Child–Pugh score of 5; the rest (31% in the radioembolization group and 40% in the chemoembolization group) had a score of 6 or 7. Six of 13 patients in the radioembolization group and 4 of 15 in the chemoembolization group had Barcelona Clinic Liver Cancer stage A disease; the rest of the patients had stage B disease.

Patients in the radioembolization group received a single brachytherapy treatment as a whole-liver, lobar, or segmental procedure (n = 13) using yttrium-90 radionuclide microspheres (32 µm; median, 1.6 Gbq). Patients in the chemoembolization group (n = 15) were treated with epirubicin 50 mg in Lipiodol 5 mL (iodized oil) and Embosphere microspheres (150 to 300 µm or 300 to 500 µm) every 6 weeks. Chemoembolization patients were assessed before each procedure, and underwent a mean of 3.5 sessions.

Treatment response was assessed by local and independent central examiners using RECIST (Response Evaluation Criteria in Solid Tumors). Patients were followed for a minimum of 12 months or until death.

Quality of Life Maintained With Either Therapy

We found "no detectable difference in health-related quality of life" between the 2 treatments over the first 12 weeks, Dr. Kolligs reported. Quality-of-life measures included dimensions of physical, social, emotional, and functional well being, as well as health concerns assessed on a hepatobiliary scale.

There was no difference between radioembolization and chemoembolization in progression-free survival, determined by intention-to treat-analysis (3.6 vs 3.7 months; log-rank P = .374).

There was also no difference in objective response rates between radioembolization and chemoembolization (23.1% vs 33.3%), and no difference in disease control rates (69.2% vs 67.7%).

At follow-up, 1 radioembolization patient and 2 chemoembolization patients were downstaged for liver transplantation. In addition, 1 radioembolization patient was downstaged for radiofrequency ablation, and that patient "has had no evidence of disease for the past 3 years," Dr. Kolligs reported.

Kaplan–Meier analysis showed no difference in survival between the radioembolization and chemoembolization groups at 6-month follow-up (69.2% vs 86.7%) or at 12-month follow-up (46.2% vs 66.7%; P = .244).

After progression, 4 patients in the chemoembolization group underwent additional treatment and 2 underwent radioembolization. One patient in the radioembolization group had additional treatment and 1 underwent additional chemoembolization.

There were 4 serious adverse events (grade 3 or 4) in each group. The most common adverse events were ascites, fatigue, and infection in the radioembolization group, and infection in the chemoembolization group.

There were only minor changes in liver function tests from baseline, and only in the radioembolization group, where total bilirubin elevations of grade 3 or higher were seen in 2 patients at 3 months and in 1 patient at 6 months.

For radioembolization, patient selection is important. "If you don't pay attention to liver function, and I guess the best parameter is bilirubin, then the patient has a risk of developing radiation-induced liver disease, which is a further impairment of liver function, ascites, and other symptoms," Dr. Kolligs told Medscape Medical News. A bilirubin level of 2 mg/dL should be the cutoff, he said.

Treatment decisions are made by an interdisciplinary tumor board. "We usually perform chemoembolization in patients with a limited number of tumor nodules that are usually not larger than 6 to 8 cm. If patients have very many nodules or very large nodules, if patients have a portal vein thrombosis, then we discuss performing radioembolization," he explained.

In response to an audience question about whether the 32 µm radioactive microspheres could end up in the systemic circulation, he said that all patients are screened with magnetic resonance angiography before initiating therapy to rule out significant shunting. In fact, 2 patients were excluded from the study for this reason.

In my opinion, these findings "show that it would be very reasonable and timely to have a large phase 3 study conducted to compare these 2 treatments in patients with intermediate [hepatocellular carcinoma] to really show where the place of this treatment could be," said Markus Peck-Radosavljevic, MD, from the Medical University of Vienna in Austria, and the new EASL secretary general.

Dr. Kolligs added a caveat: "There is definitely a place for radioembolization in the treatment algorithm. However, because of the lack of randomized clinical studies, we can't tell exactly where this place is." Unfortunately, a noninferiority trial would require 1500 patients, and a trial with adequate power to show the superiority of one treatment over the other would require 60,000 patients, Dr. Kolligs explained.

"This underscores the problem of designing a randomized controlled study for intermediate-stage hepatocellular carcinoma," he noted, but added that there are 3 trials in progress for more advanced disease.

In general, some intermediate-stage patients do quite well with chemoembolization, but others do not, Dr. Peck-Radosavljevic pointed out. "The problem is that when you do a transarterial treatment, you block the arterial blood supply to the liver. That kills the tumor but is not always good for the liver," he explained. "What you see when you're treating those patients is that some have very, very, very long survival, whereas others, who you think are in quite good condition, deteriorate very fast after this kind of treatment."

Dr. Kolligs reports being a speaker for Sirtex Medical, Bayer, and Pfizer, and a member of the advisory board for Bayer. Dr. Peck-Radosavljevic reports being a consultant to AbbVie, Roche, Bayer, Bristol-Myers Squibb, Boehringer Ingelheim, Gilead Sciences, Janssen, Eli Lilly, Jennerex, Merz, MSD, and Novartis.

International Liver Congress 2013: 48th Annual Meeting of the European Association for the Study of the Liver (EASL). Abstract 114. Presented April 27, 2013.

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Coumarin in Cinnamon and Cinnamon-Based Products and Risk of Liver Damage

"True," or Ceylon, cinnamon is expensive, so most breads, sticky buns and other products in the United States use dried cassia bark, or cassia cinnamon. (Credit: © Jacek Chabraszewski / Fotolia)

May 8, 2013 — Many kinds of cinnamon, cinnamon-flavored foods, beverages and food supplements in the United States use a form of the spice that contains high levels of a natural substance that may cause liver damage in some sensitive people, scientists are reporting. Their study, published in ACS' Journal of Agricultural and Food Chemistry, found similar results as those published in the European Union.

Ikhlas Khan and colleagues explain that cinnamon, which comes from the bark of certain trees, is one of the most important flavoring agents used in foods and beverages. "True," or Ceylon, cinnamon is expensive, so most breads, sticky buns and other products in the United States use dried cassia bark, or cassia cinnamon.

Ceylon cinnamon contains very little coumarin, a naturally occurring substance that has been linked to liver damage in people sensitive to the substance. However, cassia cinnamon can contain larger amounts. Khan's team decided to check on the coumarin content of a wide variety of food products.

"As found in this study, coumarin was present, sometimes in substantial amounts, in cinnamon-based food supplements and cinnamon-flavored foods," they say.

Story Source:

The above story is reprinted from materials provided by American Chemical Society.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Yan-Hong Wang, Bharathi Avula, N. P. Dhammika Nanayakkara, Jianping Zhao, Ikhlas A. Khan. Cassia Cinnamon as a Source of Coumarin in Cinnamon-Flavored Food and Food Supplements in the United States. Journal of Agricultural and Food Chemistry, 2013; 61 (18): 4470 DOI: 10.1021/jf4005862

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Reducing Risk for Mother-to-Infant Transmission of Hepatitis C Virus: A Systematic Review for the U.S. Preventive Services Task Force

Annals of Internal Medicine

15 January 2013, Vol 158, No. 2>

Erika Barth Cottrell, PhD, MPP; Roger Chou, MD; Ngoc Wasson, MPH; Basmah Rahman, MPH; and Jeanne-Marie Guise, MD, MPH

[+-] Article and Author Information

Abstract

Background: Mother-to-infant transmission is the leading cause of childhood hepatitis C virus (HCV) infection, with up to 4000 new cases each year in the United States.

Purpose: To evaluate effects of mode of delivery, labor management strategies, and breastfeeding practices on risk for mother-to-infant transmission of HCV.

Data Sources: MEDLINE (1947 to May 2012), the Cochrane Library Database, clinical trial registries, and reference lists.

Study Selection: Randomized trials and observational studies on mode of delivery, labor management strategies, and breastfeeding practices and risk for mother-to-infant transmission of HCV.

Data Extraction: Investigators abstracted and reviewed study details and quality using predefined criteria.

Data Synthesis: Eighteen observational studies evaluated the association between mode of delivery, labor management strategies, or breastfeeding practices and risk for mother-to-infant HCV transmission. Fourteen studies (2 good-quality, 4 fair-quality, and 8 poor-quality studies) found no clear association between mode of delivery (vaginal versus cesarean delivery) and risk for transmission. Two studies (1 good-quality and 1 poor-quality study) reported an association between prolonged duration of ruptured membranes and increased risk for transmission. Fourteen studies (2 good-quality, 2 fair-quality, and 10 poor-quality studies) found no association between breastfeeding and risk for transmission.

Limitations: Only English-language articles were included. Studies were observational, and most had important methodological shortcomings, including failure to adjust for potential confounders and small sample sizes.

Conclusion: No intervention has been clearly demonstrated to reduce the risk for mother-to-infant HCV transmission. Avoidance of breastfeeding does not seem to be indicated for reducing transmission risk.

Primary Funding Source: Agency for Healthcare Research and Quality.

An estimated 40 000 children are born to hepatitis C virus (HCV)–positive women each year (1). Mother-to-infant (vertical) transmission is the main route of childhood HCV infection (2). Estimates for the rate of vertical transmission range from 3% to 10% (2 - 5). Risk for transmission is highest among women with a high viral load at delivery (2 - 6) and those co-infected with HIV (5,7). Although antiviral therapies are contraindicated in pregnancy because of teratogenic risks, prenatal HCV screening to identify HCV-infected women unaware of their status might lead to other interventions during labor and delivery or in the perinatal period that reduce risk for mother-to-infant transmission (8).

The purpose of this review was to synthesize the evidence on the effects of mode of delivery, labor management strategies, and breastfeeding practices on risk for mother-to-infant transmission. This review was performed as part of a larger report on HCV screening (9) and will be used by the U.S. Preventive Services Task Force (USPSTF) to inform its prenatal HCV screening recommendations.

Continue reading full article here …..

Adverse childhood experiences and self-reported liver disease: new insights into the causal pathway

“This is an older article but I thought it was very interesting”

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Arch Intern Med. 2003 Sep 8;163(16):1949-56.

Dong M, Dube SR, Felitti VJ, Giles WH, Anda RF.

Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. mfd7@cdc.gov

Abstract

OBJECTIVE: To examine the relationship of adverse childhood experiences (ACEs), including abuse, neglect, and forms of household dysfunction, to the risk of liver disease by assessing the role of risk behaviors, such as substance abuse and high-risk sexual activity, as mediators of the ACEs-liver disease relationship.

METHODS: Retrospective cohort study data were collected from 17 337 adult health plan members through a survey. Logistic regression adjusted for age, sex, race, and education was used to estimate the strength of the ACEs-liver disease relationship and the impact of the mediators in this relationship.

RESULTS: Each of 10 ACEs increased the risk of liver disease 1.2 to 1.6 times (P<.001). The number of ACEs (ACE score) had a graded relationship to liver disease (P<.001). Compared with persons with no ACEs, the adjusted odds ratio of ever having liver disease among persons with 6 or more ACEs was 2.6 (P<.001). The ACE score also had a strong graded relationship to risk behaviors for liver disease. The strength of the ACEs-liver disease association was reduced 38% to 50% by adjustment for these risk behaviors, suggesting they are mediators of this relationship.

CONCLUSIONS: The ACE score showed a graded relationship to the risk of liver disease that appears to be mediated substantially by behaviors that increase the risk of viral and alcohol-induced liver disease. Understanding the effect of ACEs on the risk of liver disease and development of these behaviors provides insight into causal pathways, which may prove useful in the prevention of liver disease.

Comment in: Adverse childhood experiences, obesity, and liver disease. [Arch Intern Med. 2004]

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For chronic hepatitis C patients and their doctors, treatment discussions shouldn't wait

Provided by The Clay Times Journal

Sunday, May 12, 2013 5:32 AM EDT

(BPT) - For the estimated 3.2 million Americans living with chronic hepatitis C, talking to a physician about treatment options for the disease now is an important first step. Untreated chronic hepatitis C may lead to serious health consequences, including cirrhosis - or permanent scarring of the liver - liver failure and liver cancer.

Following a diagnosis of chronic hepatitis C, a patient should ask their physician whether the liver is already damaged and whether they should begin treatment. The long-term consequences of not treating chronic hepatitis C may increase over time. The longer a patient waits to get treated for chronic hepatitis C, the more likely they are to experience severe liver damage that may make it more difficult to treat the infection.

“Guidelines issued by the Centers for Disease Control and Prevention advocate testing baby boomers born between 1945 and 1965 for chronic hepatitis C today,” says Dr. Eirum Chaudri, executive director of medical affairs at Merck. “As liver damage progresses, the likelihood of responding to treatment decreases; so testing is critical to disease identification and management.”

Anyone can be infected with chronic hepatitis C, but certain populations are more at risk than others including baby boomers, veterans and Hispanic-Americans. Given that these populations are at greater risk for the disease, it is important that they consider getting tested for hepatitis C. Testing for hepatitis C can be done with a blood test.

Patients with chronic hepatitis C should feel comfortable discussing their condition with their physician, including their treatment options. Healthcare providers are the best source of information about your medical condition.

Merck and the American Liver Foundation are teaming up to urge Americans to take action and learn more about chronic hepatitis C today. Visit www liverfoundation.org to learn more.

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Now the Tough Part

Provided by PsychCentral.com

An Epidemic of Addiction Blog

By J.T. Junig,  MD, PhD

The forces of nature appear intent on reversing mankind’s progress toward better health. An example is the ever-increasing resistance of bacteria to antibiotics. A timeline of the existence of humans and bacteria shows that bacteria have been around for a very long time— much longer than mammals, and much, much longer than humans. In fact by the dawn mankind, bacteria had been thriving, relatively uninhibited, for over 2 billion years.

Modern humans have been around for 40,000-200,000 years or so, depending on the definition of ’modern.’ Bacteria have had the upper hand during all of mans’ existence, save for the past 100 years after penicillin and other antibiotics were discovered. Only the most self-centered of species would look at a timeline and conclude that humans have won the battle with bacterial diseases. There are always reasons for optimism, but a fair assessment of our current struggle with antibiotic resistance suggests that someday, people will look back on the current sliver of time, when humans can treat most bacterial infections, as a golden era of medicine that wasn’t appreciated as such at the time.

Viruses adapt to mankind’s health efforts too, with new variants arising from the sludge at the bottom of the food chain to infect birds, swine, or other creatures before moving on to human hosts. The CDC and other scientists work to predict the vulnerabilities of the next super-virus, hoping to reduce the severity of the next pandemic. As with bacteria, we are enjoying an era without smallpox, polio, or other dreaded viral diseases that used to kill otherwise-healthy people. We take the victor’s position for granted to the point that our children don’t know why chlorine was first added to swimming pools. Gone with the last generation are the fears associated with iron lungs, orange window-signs, and leg braces.

Even the Human Immunodeficiency Virus, an agent of certain death in the 1980’s was transformed into a chronic, treatable illness. I was new to medicine when ‘universal precautions’ were first instituted (can our children even imagine having their teeth examined by someone not wearing latex gloves?!) Researchers don’t celebrate, though, since medication-resistant strains of HIV were expected to emerge– and have emerged.

As a medical student I learned about ‘non-A non-B hepatitis’, a small concern at the time that has since grown into the identity of ‘Hep C’ (Funny how long it took to come up with THAT name!) Hepatitis C is a major public health threat, since routine vaccinations for hepatitis B and the surge in IV drug use.

Not all diseases are from non-human entities. Cancers, for example, arise from errors in our own DNA, either inherited or acquired. Cures have been found for a few cancers, but like bacteria, cancers have emerged that are resistant to current chemotherapeutic drugs, requiring a constant search for new agents.

Some illnesses are considered ‘lifestyle diseases’ because they are related to obesity, smoking, pollution, substance use, inactivity, or poor diet— such as hypertension, heart disease, diabetes, cerebrovascular disease, asthma, and COPD. The model of resistance show by bacteria doesn’t fit in the same way, but many of these illnesses draw public attention as ‘epidemics’ that demand resources, with apathy or cultural phenomena function acting as resistance to those efforts.

Bear with me; I’m working up to something that I’ve alluded to before. My point is that like with other illnesses, addiction doesn’t respond to medications– Suboxone and buprenorphine — quite the way it used to.

When Suboxone hit the US market in 2003, large numbers of opioid addicts were scattered across the country, sick and tired of their dependence on opioids. Heroin was considered a ‘bad drug’ back then even by those with severe addictions, and was rarely encountered by teens and young adults. Most opioid addicts used hydrocodone or oxycodone, prescribed by doctors or obtained from people with prescriptions. Heroin was marginalized to those with the most-severe addictions, or used sporadically in combination with other drugs (e.g. speedballing). Known doses of oxycodone were comparatively safer than heroin, which is stepped on to varying amounts and sometimes laced with deadly fentanyl. Oxycodone was absorbed through mucous membranes more quickly than heroin, meaning lower motivation to use needles. So in the early 2000’s, some people addicted to opioids found a way to get by, albeit in state of chronic misery and loneliness after spouses and friends moved away.

Enter Suboxone– a new medication to treat opioid dependence. Suboxone carried some controversy, as some in the non-medication treatment lobby did their best to tarnish the medication (as in ‘you’re not as clean as I am!). But despite the tarnish, Suboxone and buprenorphine were medications that were to be prescribed by doctors. People who for years kept the same horrible secret were given an option that actually worked. People returning to my office for follow-up had tears of happiness on their faces; they thought they would never be free from their afflictions, and were grateful as Hell for a chance to return to the living.

Many of those patients have done well for years, in treatment in my practice and others. Many are still on buprenorphine and grateful to be on buprenorphine, as happy and productive as they’ve ever been in life, with no desire to change.

But then, just as some of us were becoming optimistic about this great new medication, the disease of addiction changed in the direction that all diseases change– for the worse. The substrate changed; oxycodone was largely removed from the market through well-intentioned anti-diversion efforts that made Oxycontin harder to abuse… just as the US experienced a large influx of cheap heroin. And as in the 1960′s, heroin brought out needles– something that many opioid addicts used to take pride in for not considering.

And Suboxone changed. People on buprenorphine or Suboxone sometimes shared a bit of their medication with friends going through dry spells. Some people on Suboxone or buprenorphine sold portions of their prescriptions. The image of Suboxone held by active heroin addicts changed from doctor’s medication to a self-directed treatment for withdrawal. In fact, the perceived roles of patient vs. treatment provider became blurred by needle exchange programs and programs that provide addicts with syringes loaded with naloxone. Against a confusing backdrop of publicly-provided needles, free syringes pre-loaded with naloxone, and expensive brand film vs. affordable generic buprenorphine, the image of Suboxone turned from orange to gray.

I don’t mean to criticize the well-intentioned efforts to save lives, such as the distribution of naloxone in areas where overdoses have become epidemic. It’s hard to predict unintended consequences. But now, new patients consist of 18-y-o heroin addicts who see Suboxone as a tool to provide cover for a few days, when the heroin supply runs dry. Some see Suboxone as a tool to detox, although the detoxes never accomplish anything at all—the ultimate bridge to nowhere. The bottom line is that after seeing a few Suboxone tablets ground up, dissolved, cooked, and injected, the medication loses a bit of luster.

And finally, patients themselves have changed. Opioid addicts in 2013 are often acutely ill from unknown doses, toxic fillers, and dirty needles, presenting to ER’s with antecubital abscesses and hepatitis C. And despite being very, very sick, many haven’t had enough time to get sick and TIRED. Being started on Suboxone is less of a bit deal because they’ve BEEN on Suboxone— little chips of it, over and over and over, whenever the heroin ran out.

Gone are the easy buprenorphine patients. Now we have young, fresh, sick addicts who won’t live long enough to hate their addictions. Addiction as a disease has adapted to our treatment efforts, and become stronger– and deadlier. Our side had better keep up the hard work.

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Electron-beam pasteurization of raw oysters may reduce viral food poisoning

Results of a recent study by Texas A&M University System personnel and others on the effects of electron beam irradiation on viruses in raw oysters will be published in the June issue of the Applied and Environmental Microbiology journal. (U.S. Department of Agriculture — Agricultural Research Service photo by David Kingsley)

April 30, 2013

By: Paul Schattenberg, 210-467-6575, paschattenberg@ag.tamu.edu

Contact: Dr. Suresh Pillai, 979-458-1640, s-pillai@tamu.edu

Chandni Praveen, chandni.vs@gmail.com.

Research to be published in June issue of leading microbiology journal

COLLEGE STATION – According to the Centers for Disease Control, about one in six Americans gets food poisoning each year. Additionally, virus infection risks from consumption of raw oysters in the U.S. are estimated to cost around $200 million a year.

To address the issue of health risk from eating raw oysters, Texas A&M University graduate student Chandni Praveen, along with Texas A&M AgriLife Research scientist Dr. Suresh Pillai and a team of researchers from other agencies and institutions, studied how electron-beam pasteurization of raw oysters may reduce the possibility of food poisoning through virus.

Other entities involved in the study included the U.S. Department of Agriculture, the U.S. Food and Drug Administration and University of Texas School of Public Health-El Paso regional campus.

The results of this study will be published in the June issue of the leading microbiology journal, Applied and Environmental Microbiology.

“The study was performed using a human norovirus surrogate called murine norovirus (NoV), and a hepatitis A (HAV) virus along with advanced quantitative microbial risk assessment tools,” explained Pillai, professor of microbiology and director of the National Center for Electron Beam Research at Texas A&M University. “A salient feature of e-beam pasteurization technology is that it uses commercial electricity to generate the ionizing radiation that inactivates the viruses. It is a green technology because no chemicals are involved.”

Pillai said the FDA already has approved the use of electron beam technology as a pathogen intervention strategy to control the naturally occurring Vibrio vulnificus bacterial pathogen in shellfish.

According to the FDA, raw oysters contaminated with Vibrio vulnificus can be life threatening or even fatal when eaten by someone with liver disease, diabetes or a weakened immune system.

“We’re all for any means of technology that enhances the safety of our product,” said Sal Sunseri, co-owner of P&J Oysters and a representative of the Louisiana Oyster Dealers and Growers Association. “While we provide a safe product, we know there are at-risk groups, and that processing methods like freezing, high-pressure treatment and electron-beam irradiation reduce or eliminate the risk for those groups and enhance the overall safety of our product.”

At this time, however, electron-beam technology is not being used for commercial oysters sold in the U.S.

“For the study, we chose the norovirus and hepatitis A virus, as these are pathogenic threats to those consuming shellfish, and chose oysters as they are a type of mollusk that’s more commonly eaten raw,” said Praveen, a doctoral candidate in the toxicology program of the Food Safety and Environmental Microbiology Laboratory at Texas A&M.

Praveen said she and the other researchers also chose the viral pathogens as opposed to bacterial as they were more difficult to treat and also require a host species.

“Bivalves such as oysters are also filter feeders that obtain their food by pumping water through their system and filtering small organisms,” she said. “This can lead to the possible accumulation of NoV and HAV viral pathogens, as well as bacterial pathogens.”

Pillai said non-thermal food processing technologies are needed to reduce these infection risks.

“This is the first study that has attempted to quantify the reduction in infection risks of raw oysters contaminated with different levels of virus when pasteurized at FDA-approved doses,” he said.

Pillai said that the study showed if a serving size of 12 raw oysters were contaminated with approximately 100 hepatitis A and human noroviruses, an e-beam dose of 5 kGy (kilograys) would achieve a 91 percent reduction of hepatitis A infection risks and a 26 percent reduction of norovirus infection risks. A kilogray is a unit of absorbed energy from ionizing radiation.

Pillai said the study showed that if electron-beam pasteurization technology was included as part of a comprehensive food safety plan to reduce illnesses from raw oysters, significant public health benefits and, by extension, significant savings in medical and related expenses due to foodborne illness, can occur.

The study can be found in the June issue of Applied and Environmental Microbiology or online at the American Society of Microbiology website, http://aem.asm.org.

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