Salmonella cases double in Denmark

Ben Hamilton of CPH Post reports there were twice as many salmonella outbreaks in Denmark in 2017 than in the previous year.

In total, there were 25 outbreaks, and 1,067 people became ill as a result.

The increase is partly blamed on improved ways of detecting outbreaks. ‘Whole genome sequencing’, for example, makes it easier to detect the same source of infection.

“We hope it can lead to a decline in salmonella cases in the long term,” noted Luise Müller, an epidemiologist at Statens Serum Institut.

“It should enable us to become better at deducing why some foods are more likely to make people sicker than others.”

Danish-produced pork was the biggest culprit, while there were no cases sourced to chicken.

Foodborne outbreaks in general are increasing. In 2017, there were 63, up from 49 in the previous year.

The biggest culprit is campylobacter, a bacterium that made 4,257 people ill in 2017.

Just cook it doesn’t cut it: Campy in veal liver

A matched case–control study in Quebec, Canada, evaluated consumption of veal liver as a risk factor for campylobacteriosis. Campylobacter was identified in 28 of 97 veal livers collected concurrently from slaughterhouses and retailers. Veal liver was associated with human Campylobacter infection, particularly when consumed undercooked.

Recent investigations conducted in Quebec, Canada, after an increased number of sporadic campylobacteriosis illnesses suggested that consumption of veal liver may be a risk factor for campylobacteriosis. Many of the persons infected reported eating veal liver, and many of those had eaten it pink or undercooked. The association between campylobacteriosis and the consumption of meat products, including chicken liver and offal from different animal species, has been previously described (1–5). We designed an epidemiologic study to examine the relationship between veal liver consumption and campylobacteriosis.

We conducted a matched case–control study to examine a potential association between veal liver consumption and campylobacteriosis, using salmonellosis cases as controls. The study began in September 2016 and continued for 9 months. Salmonellosis and campylobacteriosis cases are reportable in Quebec; we selected all subjects from the provincial reportable disease registry. We used a systematic sampling method to select every fifth reported campylobacteriosis case-patient >45 years of age. We paired each campylobacteriosis case-patient with 1 salmonellosis case-patient by age group (45–64 and >65 y) and sex; both infections were confirmed by fecal culture. We matched case-patients if the salmonellosis sample was collected within a window of 7 days before to 60 days after the campylobacteriosis sample was collected. Inclusion criteria for cases and controls were infection that was sporadic and domestically acquired. Exclusion criteria were co-infection with another pathogen, being part of a recognized outbreak, or contact with a gastroenteritis case-patient <10 days before illness.

We administered a structured questionnaire by telephone to collect information on exposures in the 7 days before illness onset. Exposures were consumption of meat and unpasteurized milk products, contact with animals, drinking and recreational water exposures, and occupational exposures. In particular, we investigated consumption of a variety of livers and the degree to which they were cooked. We conducted matched univariate and multivariate analysis to estimate odds ratios (OR) for each exposure.

In addition, we collected samples of veal, chicken, pork, and beef livers from slaughterhouses and retail stores in Quebec between October 2014 and March 2017. We tested each liver specimen for the presence of Campylobacter, Salmonella, and Escherichia coli O157:H7 by using standardized methods (6,7).

We matched a total of 112 campylobacteriosis cases to salmonellosis cases. We found no significant statistical difference in the age or sex distribution of retained cases or controls and the excluded patients. The species of Campylobacter were C. jejuni (79.5%), C. jejuni/coli undifferentiated (3.6%), C. coli (0.9%), other (1.8%), and not identified (14.3%). Among campylobacteriosis case-patients, 42 (37.5%) consumed veal liver and 29 (69.0%) ate it undercooked.

Only the consumption of veal liver and having contact with farm animals were statistically significantly associated with campylobacteriosis (Table 1). After applying the Bonferroni correction to adjust for multiple comparisons (0.05 level of significance divided by 45 variables tested yields α = 0.001), only veal liver consumption remained as a statistically significant exposure (matched OR 9.50, 95% CI 3.39–26.62; p = 0.000001).

Among veal liver consumers, adequate cooking (e.g., well-cooked vs. pink or rare, on the basis of the participant’s subjective observation) was protective. Specifically, 13 (30.2%) of 43 case-patients versus 6 (85.7%) of 7 controls ate their veal liver well-cooked (unmatched OR 0.07, 95% CI 0.002–0.72; p = 0.02). Multivariate analysis using logistic regression confirmed that a statistically significant association between the consumption of veal liver and campylobacteriosis remained when all other exposures were included as covariates. Although we conducted this study among persons ≥45 years of age, it is reasonable to assume that eating veal liver, especially undercooked, would also carry risk for younger persons.

We sampled 339 veal, pork, chicken, and beef livers collected from 138 retailers and 16 slaughterhouses. When we evaluated all livers collected at both locations, we detected Campylobacter in 28.0% of veal livers, 22.2% of pork livers, 36.8% of chicken livers, and 19.1% of beef livers (Table 2). We detected Salmonella more frequently in chicken livers (22.1%) and pork livers (19.1%) than in veal livers (3.1%); we did not detect Salmonella in beef livers. We rarely identified E. coli O157:H7 in livers of any kind. The proportion of contaminated livers differed between animal species and also with respect to location of sampling. A higher proportion of veal livers (35.7%) collected from retailers were contaminated by Campylobacter, compared with veal livers collected from slaughterhouses (16.2%). We observed the reverse for chicken and pork livers. The reason for these variations is unclear at this time, but this finding may be an artifact resulting from the relatively small number of samples taken at each location.

Cattle are a well-known reservoir for a variety of Campylobacter species, such as C. jejuni, C. coli, and C. fetus (8,9). Campylobacter species have been isolated from beef intestinal contents and also from beef bile, bile ducts, gallbladder, and liver (10–14). The gallbladder and bile contain substances that have a chemoattractant effect on C. jejuni, which explains the presence of Campylobacter within the biliary tract (10,15). Liver contamination varies between animal species (10–14). Chicken liver, for example, can be contaminated by Campylobacter and Salmonella and has been the source of several outbreaks (3,4,11,13). Because few case-patients consumed livers from other animal species during our study, we were not able to identify any substantial risks associated with those exposures.

Because livers may be collected from several animals and stored together, they may be contaminated during the evisceration process or by cross-contamination (11). Both the external and internal tissue of a liver may be contaminated with Campylobacter, and inadequate cooking may not fully inactivate Campylobacter and Salmonella (10,11), which is a cause for concern because ≈70% of the patients with campylobacteriosis who consumed veal liver in our study reported eating it undercooked. We did not examine possible cross-contamination of foods and surfaces and the host-related factors that may increase the risk for enteric diseases.

Conclusions

Our study identified a strong and statistically significant association between the consumption of veal liver and sporadic, domestically acquired campylobacteriosis among persons >45 years of age in Quebec. We found that adequate cooking of veal liver mitigates the risk of infection. We detected Campylobacter in almost one third of veal livers we sampled from slaughterhouses and retail stores, which supports our finding that veal liver consumption is a risk factor for campylobacteriosis. In light of these results, we recommend the dissemination of safe food handling practices for veal liver and other offal for retailers, food establishments, slaughterhouses, and the general public.

Dr. Gaulin is a physician epidemiologist who works in public health at the Protection Branch of the Ministry of Health in Quebec, Canada. She works in infectious diseases on enteric and nonenteric disease surveillance and also coordinates provincial outbreak investigations.

Veal Liver as Food Vehicle for Human Campylobacter Infections

Gaulin C, Ramsay D, Réjean Dion R, Simard M, Gariépy C, Levac É, et al. Veal liver as food vehicle for human Campylobacter infections. Emerg Infect Dis. 2018 Jun [date cited]. https://doi.org/10.3201/eid2406.171900

DOI: 10.3201/eid2406.171900

https://wwwnc.cdc.gov/eid/article/24/6/17-1900_article#suggestedcitation

NZ poultry industry calls chicken contamination findings ‘scaremongering’

That didn’t take long.

Nor should it.

But the so-called experts undermine their case by not advocating the use of a tip-sensitive digital thermometer and instead relying on the woefully unreliable color test (‘chicken must be fully cooked through until juices run clear) for safety.

A new University of Otago, Wellington study, published last week in the international journal BMC Public Health found an overwhelming majority of consumers were not aware of the widespread Campylobacter contamination.

But the Poultry Industry Association of New Zealand is challenging the findings, which it says does not reflect reported Campylobacter statistics nor consumer behaviour.

PIANZ executive director Michael Brooks said the findings did not add up with New Zealand’s soaring chicken consumption, and flat rates of reported campylobacter cases.

“Reported cases of campylobacter have sat between 6000 to 7000 for the past five years, so it’s misleading to estimate there are 30,000 cases occurring,” Brooks said.

“It is important to note that the source of these cases was not always chicken.

“Consumers contract campylobacteriosis from other sources too.”

Brooks said the poultry industry had made significant changes when it came to labelling for food safety.

The association lost control of that access to information once third parties like butchers or supermarkets started packaging their own raw chicken product.

“As an industry it is important for everyone to educate their customers on food safety practices.”

Brooks said he welcomed a collaborative approach with institutions such as Otago University, as consumer education was key to reducing cases of campylobacter.

Campy in NZ poultry: ‘Warning labels required’

(Doesn’t say if the study has been published in a peer-reviewed journal.)

New Zealanders want brightly coloured warning labels on fresh chicken to warn them of the risks of the country’s “number one food safety problem”, new research suggests.

A University of Otago study found only 15 per cent of consumers were aware that 60 to 90 per cent of fresh chicken meat for sale in New Zealand is contaminated with campylobacter.

“This study has identified some clear gaps in campylobacteriosis prevention in New Zealand,” University of Otago infectious diseases researcher Professor Michael Baker said.

“Fresh chicken is heavily contaminated with campylobacter and causes an estimated 30,000 New Zealanders to get sick each year. “

Fresh chicken was also spreading antibiotic resistant bacteria and was “New Zealand’s number one food safety problem”, Baker said.

Speaking on Mike Hosking Breakfast today, he said people were still getting sick as a result of not carrying out best practice when preparing fresh chicken – including not adequately cleaning bench surfaces or sinks that have come in contact with it.

Baker said a label would need good information to help a consumer, but would need to be tested.

He said labels to should read something like: “This food should be treated with care.”

The study was based on interviews with 401 shoppers over 16 who were recruited outside 12 supermarkets and six butcheries in the Wellington Region

“New Zealand has one of the highest rates of campylobacteriosis in the world and at least half of cases can be attributed to contaminated chicken,” Philip Allan, a medical student and researcher at the Department of Public Health, University of Otago Wellington (UOW), said.

“Our study showed that many consumers are not aware of the risks, and that retailers should do much more to inform shoppers.”

The study also assessed the quality of current chicken labelling in supermarkets and butcheries and identified major deficiencies in the safety information provided to consumers.

Butchery labels in particular were lacking in chicken preparation information.

More than half wanted the levels of campylobacter contamination reported, the study found.

“Most participants thought a large, brightly coloured warning label containing safety information would be the most effective for communicating safe chicken preparation information.”

The study’s researchers said the most effective way to reduce campylobacteriosis rates is for Ministry for Primary Industries to mandate lower contamination levels of fresh poultry.

“This measure has been highly effective in the past, halving the rate of campylobacteriosis in New Zealand when implemented in 2007.
“While improved labelling is important, it is no substitute for cleaning up our poultry,” Baker said.

Raw is risky: 17 sick with Campylobacter from raw milk in Colorado, 2016

In August 2016, a local public health agency (LPHA) notified the Colorado Department of Public Health and Environment (CDPHE) of two culture-confirmed cases of Campylobacter infection among persons who consumed raw (unpasteurized) milk from the same herdshare dairy.

In Colorado, the sale of raw milk is illegal; however, herdshare programs, in which a member can purchase a share of a herd of cows or goats, are legal and are not regulated by state or local authorities. In coordination with LPHAs, CDPHE conducted an outbreak investigation that identified 12 confirmed and five probable cases of Campylobacter jejuni infection. Pulsed-field gel electrophoresis (PFGE) patterns for the 10 cases with available isolates were identical using the enzyme Sma. In addition, two milk samples (one from the dairy and one obtained from an ill shareholder) also tested positive for the outbreak strain. Five C. jejuni isolates sent to CDC for antimicrobial susceptibility testing were resistant to ciprofloxacin, tetracycline, and nalidixic acid (1).

Although shareholders were notified of the outbreak and cautioned against drinking the milk on multiple occasions, milk distribution was not discontinued. Although its distribution is legal through herdshare programs, drinking raw milk is inherently risky (2). The role of public health in implementing control measures associated with a product that is known to be unsafe remains undefined.

Investigation and Results

On August 23, 2016, El Paso County Public Health notified CDPHE of two culture-confirmed cases of C. jejuni infection; campylobacteriosis is a reportable disease in Colorado. Both patients reported drinking unpasteurized milk from the same herdshare dairy in Pueblo County. Since 2005, obtaining raw milk by joining a herdshare program has been legal for Colorado residents, but selling raw milk is illegal. By purchasing a share of a herd (cows or goats), shareholders are entitled to a portion of the raw milk.

Because the prevalence of consuming unpasteurized milk is low (2.4% in Colorado, 2006–2007 FoodNet Population Survey; 3.1%, 2009 Colorado Behavioral Risk Factor Surveillance System), two cases of enteric illness with a common exposure to raw milk are unlikely to occur by chance (3,4). In this outbreak, a confirmed case was defined as diarrheal illness with onset on or after August 1, 2016, in a person with known consumption of unpasteurized milk from the same herdshare dairy and culture-confirmed C. jejuni infection. A probable case was defined as diarrhea onset on or after August 1, lasting 1 or more days, in a person with either known consumption of milk from the same herdshare dairy or with an epidemiologic link to a confirmed case.

Cases were identified through routine passive reporting with follow-up interviews, a Health Alert Network broadcast to area providers, and attempts to contact all shareholders. A public health order was issued to obtain a list of shareholders with their contact information after it was not provided by the dairy within 5 days of the initial request. CDPHE attempted to contact shareholders to inform them about the outbreak and assess possible illness. Up to three calls were made to each shareholder household. Epidemiologists contacted laboratories to request that isolates from potential outbreak-associated cases be forwarded to the state public health laboratory.

Among 91 (53%) of 171 shareholder households that responded to requests for follow-up interviews, representing 207 persons in five or more Colorado counties, 12 confirmed and five probable cases were identified (Figure). Among confirmed cases, patients ranged in age from 12 to 68 years (median = 58 years); nine were male. Duration of illness ranged from 3 to >10 days. One hospitalization occurred; there were no deaths. In addition to diarrhea, among the 12 confirmed cases, the majority of patients also experienced fever (10), abdominal pain or cramps (eight), headache (eight), and myalgia (seven); vomiting and bloody diarrhea were reported less frequently (in five and four persons, respectively).

Four milk samples were tested for C. jejuni; pathogen identification and PFGE were performed on available isolates from persons epidemiologically linked to the outbreak. C. jejuni with one of two outbreak PFGE patterns (PulseNet DBRS16.0008 using the enzyme Sma and PulseNet DBRK02.1272 or DBRK02.0028 using the enzyme Kpn) was confirmed in 10 isolates that were available at the public health laboratory and two of the four raw milk samples. The National Antimicrobial Resistance Monitoring System performed antimicrobial susceptibility tests on five representative isolates; all were resistant to ciprofloxacin, tetracycline, and nalidixic acid (1).

Public health responses to this outbreak consisted of notifying shareholders about the outbreak on three occasions and requiring the dairy to provide additional written notification about the outbreak at milk distribution points. A press release was issued by two LPHAs in response to detecting at least one infection in a person who was not a shareholder but was given milk by shareholders. In addition, a number of shareholders reported sharing milk with nonshareholders who might have been unaware of the outbreak. Although milk sample results were positive for C. jejuni, CDPHE did not close the dairy or stop distribution of its milk because without pasteurization CDPHE could not create standards for safely reopening the dairy (5). Shareholders were, however, urged to discard raw milk distributed since August 1 and were reminded that Colorado statute prohibits redistribution of raw milk.

Discussion

Raw milk from a herdshare dairy was the source of this outbreak of C. jejuni infections, and the investigation highlighted the difficulties inherent in addressing an outbreak related to unpasteurized milk from a herdshare dairy. During three previous herdshare-associated outbreaks in Colorado, public health authorities temporarily took action to stop milk distribution until a series of negative tests were obtained from the milk (Alicia Cronquist, CDPHE, personal communication, December 2017). However, because CDPHE could not ensure that unpasteurized milk would be safe in the future, the decision was made not to close the dairy during this outbreak. In addition, CDPHE’s Division of Environmental Health and Sustainability chose not to make formal recommendations on the dairy’s processes because no protocol improvements short of pasteurization could ensure the product’s safety, even with improved sanitation (5).

All tested isolates’ resistance to three antibiotics was concerning, particularly as fluoroquinolones are frequently used to treat Campylobacter infections in those cases where treatment is indicated. Treatment of antibiotic-resistant Campylobacter infections might be more difficult, of longer duration, and possibly lead to more severe illness than treatment of nonresistant Campylobacter infections (6–8). In 2015, approximately 25.3% of U.S. C. jejuni isolates were resistant to ciprofloxacin, an increase from 21.6% a decade earlier (1).

In collaboration with LPHAs, CDPHE is creating guidelines to address future outbreaks related to raw milk from herdshares. As more states legalize the sale or other distribution of unpasteurized milk, the number of associated outbreaks will likely increase (9,10). The role of public health in responding to raw milk–related outbreaks should be further defined. State-level guidelines might assist with this process.

 

Corresponding author: Alexis Burakoff, aburakoff@cdc.gov, 303-692-2745.

1Epidemic Intelligence Service, Division of Scientific Education and Professional Development, CDC; 2Colorado Department of Public Health and Environment, Denver, Colorado; 3Pueblo City-County Health Department, Pueblo, Colorado; 4El Paso County Public Health, Colorado Springs, Colorado; 5Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC.

References

CDC. National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS): human isolates surveillance report for 2015 (final report). Atlanta, Georgia: US Department of Health and Human Services, CDC; 2018.

CDC. Food safety: raw milk. Atlanta, GA: US Department of Health and Human Services, CDC; 2016. https://www.cdc.gov/foodsafety/rawmilk/raw-milk-index.html

CDC. Foodborne diseases active surveillance network (FoodNet) population survey atlas of exposures, 2006–2007. Atlanta, GA: US Department of Health and Human Services, CDC; 2011. https://www.cdc.gov/foodnet/PDFs/FNExpAtl03022011.pdf

Colorado Department of Public Health and Environment. Colorado Behavioral Risk Factor Surveillance System, 2009. [Data on raw milk]. Denver, CO: Colorado Department of Public Health and Environment; 2009. http://www.chd.dphe.state.co.us/Resources/brfss/BRFSS2009results_raw%20milk.pdf

Longenberger AH, Palumbo AJ, Chu AK, Moll ME, Weltman A, Ostroff SM. Campylobacter jejuni infections associated with unpasteurized milk—multiple states, 2012. Clin Infect Dis 2013;57:263–6. CrossRef PubMed

Evans MR, Northey G, Sarvotham TS, Rigby CJ, Hopkins AL, Thomas DR. Short-term and medium-term clinical outcomes of quinolone-resistant Campylobacter infection. Clin Infect Dis 2009;48:1500–6. CrossRef PubMed

Helms M, Simonsen J, Olsen KE, Mølbak K. Adverse health events associated with antimicrobial drug resistance in Campylobacter species: a registry-based cohort study. J Infect Dis 2005;191:1050–5. CrossRef PubMed

Nelson JM, Smith KE, Vugia DJ, et al. Prolonged diarrhea due to ciprofloxacin-resistant Campylobacter infection. J Infect Dis 2004;190:1150–7. CrossRef PubMed

Langer AJ, Ayers T, Grass J, Lynch M, Angulo FJ, Mahon BE. Nonpasteurized dairy products, disease outbreaks, and state laws—United States, 1993–2006. Emerg Infect Dis 2012;18:385–91. CrossRef PubMed

Mungai EA, Behravesh CB, Gould LH. Increased outbreaks associated with nonpasteurized milk, United States, 2007–2012. Emerg Infect Dis 2015;21:119–22. CrossRef PubMed

Outbreak of Fluoroquinolone-Resistant Campylobacter jejuni Infections Associated with Raw Milk Consumption from a Herdshare Dairy — Colorado, 2016

Morbidity and Mortality Weekly Report; February 9, 2018; 67(5);146–148

Alexis Burakoff, MD; Kerri Brown, MSPH; Joyce Knutsen; Christina Hopewell; Shannon Rowe, MPH; Christy Bennett; Alicia Cronquist, MPH

https://www.cdc.gov/mmwr/volumes/67/wr/mm6705a2.htm

Campylobacter uses other organisms to multiply and spread

Campylobacter spp. are extremely sensitive to environmental conditions and do not multiply at temperatures below 30C, however, they can survive temperatures as low as 4C for several months. They remain to be a prevalent pathogen on chicken and identified as a source of many outbreaks associated with unpasteurized milk.

Kingston University researchers have found that Campylobacter jejuni can multiply and spread using another organism’s cells.

Kingston University researchers have shown how a leading cause of bacterial food poisoning can multiply and spread – by using another organism’s cells as a Trojan horse.
Campylobacter jejuni is one of the most common causes of gastroenteritis in the United States and Europe, often infecting humans through raw or undercooked poultry. The new study revealed how the bacteria can infiltrate micro-organisms called amoebae, multiplying within their cells while protected inside its host from harsh environmental conditions.
As well as leading to a better understanding of how bacteria survive, the research could help efforts to prevent the spread of infection, according to lead author and PhD student Ana Vieira.
“Establishing that Campylobacter can multiply inside its amoebic hosts is important, as they often exist in the same environments – such as in drinking water for chickens on poultry farms – which could increase the risk of infection,” she said. “The amoeba may act as a protective host against some disinfection procedures, so the findings could be used to explore new ways of helping prevent the bacteria’s spread by breaking the chain of infection.”
The relationship between Campylobacter and amoebae has been hotly debated in scientific circles – with conflicting findings in previous studies as to whether the bacteria multiply inside, or only in the beneficial environment around, amoebae cells.
The Kingston University team used a modification of a process that assesses the bacteria’s ability to invade cells – called the gentamycin protection assay – to confirm they can survive and multiply while inside the amoeba’s protective environment.
This allows Campylobacter to thrive, escaping the amoeba cells in larger numbers – shining a light on how it spreads and causes disease, professor of microbiology Andrey Karlyshev, a supervisor on the study, explained.
“Our research gives us a better understanding of bacterial survival,” he said. “Because amoebae are widespread, we have shown how Campylobacter bacteria are able to use them as a Trojan horse for infection of the food chain. Otherwise they wouldn’t survive, as they are very sensitive to the environment.”
As part of the study, the researchers showed how a system used by the bacteria to expel toxins – known as a multidrug efflux pump – plays a key role in its ability to thrive within the amoebae.
The team examined how this system helps the bacteria become resistant to antibiotics, which could lead to new methods of preventing resistance from developing, Professor Karlyshev added.
“Campylobacter is becoming increasingly resistant to antibiotics because of their wide use on humans and animals,” he said. “Due to its role in antibiotic resistance and bacterial survival in amoebae, the efflux pump could prove to be a good target for the development of antibacterial drugs.
“Targeting the bacterial factors required for survival within amoebae could help to prevent Campylobacter from spreading in the environment and colonising chickens. This is turn could help reduce its ability to enter the food chain and cause disease in humans.”