Author Archives: Douglas Powell

About Douglas Powell

A former professor of food safety and the publisher of barfblog.com, Powell is passionate about food, has five daughters, and is an OK goaltender in pickup hockey. Download Doug’s CV here. Dr. Douglas Powell editor, barfblog.com retired professor, food safety 3/289 Annerley Rd Annerley, Queensland 4103 dpowell29@gmail.com 61478222221 I am based in Brisbane, Australia, 15 hours ahead of Eastern Standard Time

Berries on boats: You’re breakin’ my heart

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The U.S. Centers for Disease Control reports that from July to September 2019, cruise line X experienced sudden, unexplained outbreaks (>3% of the passenger population) of acute gastroenteritis (AGE) among passengers on 10 cruise ships sailing in Europe. The rapid onset of vomiting and diarrhea followed by recovery within 24 hours were consistent with norovirus infection. Investigations by the cruise line throughout the summer yielded no clear source of the outbreaks even after extensive food testing.

On September 18, 2019, CDC’s Vessel Sanitation Program (VSP) was notified of an outbreak of AGE on cruise ship A of cruise line X, sailing into U.S. jurisdiction (defined as passenger vessels carrying ≥13 passengers sailing to the United States from a foreign port) from Germany to New York City (1). By the end of the 19-day voyage on September 23, a total of 117 of 2,046 (5.7%) passengers and eight of 610 (1.3%) crew members met the case definition for AGE (three or more loose stools within a 24-hour period or more than normal for the patient, or vomiting plus one other sign or symptom including fever, diarrhea, bloody stool, myalgia, abdominal cramps, or headache).

Four stool specimens were collected and tested for norovirus at CDC’s National Calicivirus Laboratory; three tested positive for norovirus by quantitative reverse transcription–polymerase chain reaction (RT-PCR). No outbreak source was determined after a field investigation by a VSP team on September 22.

The following month, on October 7, CDC’s VSP was notified of two more outbreaks in U.S. jurisdiction. The first outbreak occurred on another ship (ship B) of cruise line X sailing to and from New York City along the eastern seaboard and affected 85 (3.9%) of 2,166 passengers and 10 (1.6%) of 612 crew members; the second outbreak occurred on ship A sailing from Montreal to New York City and affected 83 (3.7%) of 2,251 passengers and 10 (1.6%) of 610 crew members. VSP again conducted outbreak investigations on October 12 (ship B) and October 13 (ship A). Five stool specimens from ship B and two from ship A were collected for laboratory testing. During the field investigations, cruise line X’s public health officials reported to VSP that after reviewing food questionnaires completed by ill passengers on ship B, nearly 80% of completed questionnaires implicated a smoothie made from frozen fruits and berries. Because of the epidemiologic link and because berries have been implicated in past outbreaks (2,3), CDC requested assistance from the Food and Drug Administration (FDA) to collect frozen fruit and berry items from ship B for norovirus testing. Food item lot numbers from ship B matched those from the same frozen fruit and berry items on ship A.

Overall, nine of 11 stool samples from the three outbreak voyages on ships A and B tested positive for norovirus by quantitative RT-PCR at CDC; these included three of four from ship A’s first voyage, four of five from ship B, and two of two from ship A’s second voyage. The samples were typed as GII.2[P16]. FDA tested 16 frozen fruit and berry items, and three items tested positive for norovirus: raspberries (norovirus genogroup II), tropical fruit cocktail (norovirus genogroup I), and berry mix (norovirus genogroup I). Norovirus sequences from the stool samples and from raspberries were 97.5% similar. After removal of the fruit items, no further outbreaks were reported on cruise line X.

Upon further review of food provisioning, cruise line X determined that its food vendor had purchased several containers (nearly 22,000 pounds) of frozen raspberries of the same lot from a supplier in China beginning the end of June 2019. These raspberries had been supplied to the entire fleet of cruise line X. Both the epidemiologic and laboratory data implicated the raspberries as the cause of the outbreaks. As a result of these findings, on November 11, the World Health Organization issued a recall notice* for frozen raspberries traced back to China. This investigation highlights the importance of AGE surveillance at sea to prevent transmission of AGE illness through U.S. ports and to identify contaminated foods at sea that had not yet been implicated on land.

Notes from the field: Multiple cruise ship outbreaks of norovirus associated with frozen fruits and berries—United States, 2019, 24 April 2020

Morbidity and Mortality Weekly Report pg. 501-502

Jared R. Rispens, MD1,2; Amy Freeland, PhD2; Beth Wittry, MPH2; Adam Kramer, ScD2; Leslie Barclay, MPH3; Jan Vinjé, PhD3; Aimee Treffiletti, MPH2; Keisha Houston, DrPH2

https://www.cdc.gov/mmwr/volumes/69/wr/mm6916a3.htm?s_cid=mm6916a3_e&deliveryName=USCDC_921-DM26466

Herb Tarlek and Cindy Williams (not exactly as shown, below, offer their rendition.

PCR in Sweden

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Enteroinvasive Escherichia coli (EIEC) and Shigella spp. are both Gram-negative bacteria causing diarrheal disease worldwide [1,2]. The clinical presentations of these two pathogens are very similar [3,4] and commonly manifested through diarrhoea, abdominal cramps, nausea and fever both in children and adults [5,6]. In addition to a similar clinical picture, EIEC and Shigella share laboratory features that can make it difficult to distinguish between them in routine clinical laboratory practice. Both pathogens are transmitted via the faecal-oral route and infections are frequently associated with consumption of contaminated food and water [7–10]. While Shigella is associated with large-scale food-borne outbreaks [11,12], outbreaks caused by EIEC are rarely recorded.

High prevalence of EIEC infections have been documented in rural areas and settings with poor sanitation in high-risk countries [5,13] while EIEC infections in Europe are typically sporadic and travel related [14]. Nevertheless, a few EIEC outbreaks have been reported in Europe, with the most recent ones having occurred in Italy in 2012 [15] and in the United Kingdom (UK) in 2014 [16]. These outbreaks affected 109 cases and 157 probable cases, respectively, highlighting the fact that EIEC, like Shigella, has the capacity to cause large gastrointestinal disease outbreaks. The outbreak strain identified in these recent European outbreaks, EIEC O96:H19, is an emergent type of EIEC that has phenotypic characteristics more resembling those of non-invasive Escherichia coli (E. coli) than those described for Shigella [17]. These characteristics are suggested to contribute to improved survival abilities as well as the ability to better adapt to different ecological niches [17].

Traditionally, culturing of faecal specimens has been the mainstay of laboratory diagnostics for enteric bacteria, and EIEC has been differentiated from Shigella by assessing a combination of several phenotypic characteristics, including biochemical, motility and serological traits [18,19]. This is now changing as PCR-based methods are becoming routine in many diagnostic laboratories [20]. In contrast to non-invasive E. coli, EIEC and Shigella can invade and multiply in intestinal epithelial cells [21], a process that is partially mediated by the products of the invasion plasmid antigen (ipa) genes [22]. For this reason, PCR targeting the ipaH gene can separate EIEC from other non-invasive E. coli, but cannot differentiate between EIEC and Shigella [23]. The lacY gene has been proposed as an additional molecular marker for which most E. coli are positive and Shigella is negative [24]. Its use as a PCR target in separating Shigella and EIEC is restricted to bacterial isolates since many faecal samples are lacY positive because of the presence of E. coli in the normal flora.

In Sweden, several clinical laboratories have shifted towards the use of direct PCR testing on faecal specimens as the primary diagnostic tool. However, most of these laboratories culture PCR-positive samples, so called PCR-guided culturing. Although culturing of PCR-positive faecal specimens is routinely performed, it can be difficult to obtain EIEC isolates since the morphology of EIEC strains on commonly used substrates can mimic the morphology of the enteric background flora, yellow colonies on xylose lysine deoxycholate (XLD) agar, rather than the morphology of Shigella, red colonies on XLD agar. Hence, separating EIEC from other bacteria in the normal flora usually whhttps://www.technologynetworks.com/applied-sciences/news/sticker-could-improve-safety-of-our-cold-chain-food-333138?utm_campaign=NEWSLETTER_TN_Food%20%26%20Beverage%20Analysis&utm_source=hs_email&utm_medium=email&utm_content=86254121&_hsenc=p2ANqtz–MMoS1KFFGpgRZ_seNnO0bmNz_SMVvraj4jqMu9SDGvKY_0jhrfEnmyzyUGUG4KMiZPINfu3qM8tMQOAJhBtcRodwdNw&_hsmi=86254121

Which is considered too time consuming for most clinical laboratories. For this reason, it is likely that a patient with specimens that are ipaH PCR-positive but culture negative would not be notified as a case if the diagnostic algorithm at the laboratory requires a detected Shigella isolate. In addition, PCR is a more sensitive method than culturing [25] and Shigella is known for its limited survival ability in faecal samples [26], which also may lead to samples being ipaH PCR-positive but culture negative.

Shigellosis is notifiable by law in Sweden as in the majority of countries in Europe [27]. In 2017, the incidence was 2.1 per 100,000 inhabitants in Sweden, and the majority of cases had been infected abroad [28]. The mandatory reporting of diseases allows the implementation of a series of public health actions, including public health management and surveillance activities, and helps define risk exposures. In contrast to shigellosis, reporting is not mandatory for EIEC and the occurrence of this pathogen in Sweden is currently unknown.It requires additional laboratory procedures such as screening large numbers of colonies,

Outbreak of gastroenteritis highlighting the diagnostic and epidemiological challenges of enteroinvasive Escherichia coli, county of Halland, Sweden, November 2017, 12 December 2019

Eurosurveillance

Nina Lagerqvist1,2, Emma Löf1,3, Theresa Enkirch1,2, Peter Nilsson4, Adam Roth1, Cecilia Jernberg1

https://doi.org/10.2807/1560-7917.ES.2020.25.9.1900466

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.9.1900466

STEC O91 may help with the others

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Shiga toxin-producing Escherichia coli (STEC) strains are important zoonotic foodborne pathogens, causing diarrhea, hemorrhagic colitis, and life-threatening hemolytic uremic syndrome (HUS) in humans. However, antibiotic treatment of STEC infection is associated with an increased risk of HUS. Therefore, there is an urgent need for early and effective therapeutic strategies.

Here, we isolated lytic T7-like STEC phage PHB19 and identified a novel O91-specific polysaccharide depolymerase (Dep6) in the C terminus of the PHB19 tailspike protein. Dep6 exhibited strong hydrolase activity across wide ranges of pH (pH 4 to 8) and temperature (20 to 60°C) and degraded polysaccharides on the surface of STEC strain HB10. In addition, both Dep6 and PHB19 degraded biofilms formed by STEC strain HB10.

In a mouse STEC infection model, delayed Dep6 treatment (3 h postinfection) resulted in only 33% survival, compared with 83% survival when mice were treated simultaneously with infection. In comparison, pretreatment with Dep6 led to 100% survival compared with that of the control group. Surprisingly, a single PHB19 treatment resulted in 100% survival in all three treatment protocols. Moreover, a significant reduction in the levels of  proinflammatory cytokines was observed at 24 h postinfection in Dep6- or PHB19-treated mice. These results demonstrated that Dep6 or PHB19 might be used as a potential therapeutic agent to prevent STEC infection.

IMPORTANCE Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen worldwide. The Shiga-like toxin causes diarrhea, hemorrhagic colitis, and life-threatening hemolytic uremic syndrome (HUS) in humans. Although antibiotic therapy is still used for STEC infections, this approach may increase the risk of HUS. Phages or phage-derived depolymerases have been used to treat bacterial infections in animals and humans, as in the case of the “San Diego patient” treated with a phage cocktail. Here, we showed that phage PHB19 and its O91-specific polysaccharide depolymerase Dep6 degraded STEC biofilms and stripped the lipopolysaccharide (LPS) from STEC strain HB10, which was subsequently killed by serum complement in vitro. In a mouse model, PHB19 and Dep6 protected against STEC infection and caused a significant reduction in the levels of proinflammatory cytokines. This study reports the use of an O91-specific polysaccharide depolymerase for the treatment of STEC infection in mice.

 A novel tail-associated O91-specific polysaccharide depolymerase from a podophage reveals lytic efficacy of shiga toxin-producing Escherichia coli, 28 February 2020

Applied and Environmental Microbiology

Yibao Chen, Xiangmin Li, Shuang Wang, Lingyu Guan, Xinxin Li, Dayue Hu, Dongyang Gao, Jiaoyang Song, Huanchun Chen, Ping Qian

DOI: 10.1128/AEM.00145-20

https://aem.asm.org/content/86/9/e00145-20 

Me and Chapman, we love the covert studies (for science)

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Hand hygiene is one of the most effective method for preventing cross-contamination. Food handlers have a major role in the prevention of foodborne illness during food production1 , consequently food handler hand hygiene failures are frequently reported to be implicated in foodborne illness2 . Although informative, food safety cognitions are not indicative of actual practices and may be subject to biases3 , therefore food handlers may demonstrate awareness of food safety, however may fail to translate knowledge into safe practices4 .

For this reason observational data are superior to survey data5 . However, during direct observations, researcher presence can increase subject reactivity6 , whereas covert video observation provide a more comprehensive analysis over a sustained period, where familiarity reduces reactivity bias7 . Previous video observation research have assessed food handler behaviours at retail/catering settings8-10 , however, this method has been under-utilised in food manufacturing business environments. Covert observation may allow the comparison of practices in different areas of manufacturing over the same period of time.

A comparison of hand hygiene compliance in high-care and high-risk areas in a Welsh food manufacturing business using covert observation

Cardiff Metropolitan University

Ellen Evans, Catherine Bunston and Elizabeth Redmond

https://www.metcaerdydd.ac.uk/health/zero2five/research/Documents/Hand%20hygiene%20two%20areas%20EE_04_04_2019%20Final.pdf

Crypto in raw milk

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This review analysed outbreaks of human cryptosporidiosis due to raw milk. The objective of our study was to highlight and identify underestimated and underreported aspects of transmission of the parasite as well as the added value of genotyping Cryptosporidium isolates.

Methods

We conducted a descriptive literature review using the digital archives Pubmed and Embase. All original papers and case reports referring to outbreaks of Cryptosporidium due to unpasteurized milk were reviewed. The cross-references from these publications were also included.

Results

Outbreaks have been described in the USA, Australia, and the UK. Laboratory evidence of Cryptosporidium from milk specimens was lacking in the majority of the investigations. However, in most recent reports molecular tests on stool specimens along with epidemiological data supported that the infection was acquired through the consumption of unpasteurized milk. As the incubation period for Cryptosporidium is relatively long (days to weeks) compared with many other foodborne pathogens (hours to days), these reports often lack microbiological confirmation because, by the time the outbreak was identified, the possibly contaminated milk was not available anymore.

Conclusion

Cryptosporidiosis is generally considered a waterborne intestinal infection, but several reports on foodborne transmission (including through raw milk) have been reported in the literature. Calves are frequently infected with Cryptosporidium spp., which does not multiply in milk. However, Cryptosporidium oocysts can survive if pasteurization fails. Thus, pasteurization is essential to inactivate oocysts. Although cryptosporidiosis cases acquired from raw milk are seldom reported, the risk should not be underestimated and Cryptosporidium should be considered as a potential agent of contamination. Genotyping Cryptosporidium isolates might be a supportive tool to strengthen epidemiologic evidence as well as to estimate the burden of the disease.

A review of outbreaks of cryptosporidiosis due to unpasteurized milk, 15 April 2020

Infection

Tamara Ursini, Lucia Moro, Ana Requena-Méndez, Giulia Bertoli & Dora Buonfrate 

https://link.springer.com/article/10.1007/s15010-020-01426-3

Brucellosis linked with raw milk

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In December 2018, the Pennsylvania Department of Agriculture (PDA) and Pennsylvania Department of Health (PADOH) were notified of a New York patient with brucellosis caused by infection with Brucella abortus RB51, the live attenuated vaccine strain of B. abortus used to prevent brucellosis in cattle (1). Brucellosis is a serious zoonotic infection caused by the bacteria Brucella spp. The most common sign is fever, followed by osteoarticular symptoms, sweating, and constitutional symptoms (2). Without proper treatment, infection can become chronic and potentially life-threatening (2). The patient had consumed raw (unpasteurized) milk from dairy A in Pennsylvania.*

In July 2017, Texas health officials documented the first human case of domestically acquired RB51 infection associated with raw milk consumption from a Texas dairy (3). In October 2017, a second RB51 case associated with raw milk consumption was documented in New Jersey†; the milk source was not identified at the time.

To determine the RB51 source for the New York case, PDA conducted an environmental investigation at dairy A in December 2018. PDA collected individual milk samples from all cows, excluding those known not to have been vaccinated against B. abortus, and from the bulk milk tank, which included milk pooled from all cows. All milk samples underwent polymerase chain reaction (PCR) testing and culture; whole-genome sequencing (WGS) was performed on patient and milk sample isolates. PDA conducted a traceback investigation of any cow with a milk sample that tested positive for RB51. PADOH worked with the raw milk cooperative that distributed dairy A’s milk to notify potentially exposed consumers and distributed notifications through Epi-X§ to identify cases.

Dairy A sold only raw milk and did not provide RB51 vaccination to cows born there (16 of the 30-cow herd). The remaining 14 cows were born outside the dairy and had inadequate vaccination records to determine whether they had received RB51. Because these cows might have been vaccinated, milk samples were collected from them. RB51 was detected by PCR and isolated in milk samples collected from the bulk tank and a single cow (cow 122). WGS identified two distinct RB51 strains shed by cow 122: one matched the 2018 New York patient’s isolate (3 single nucleotide polymorphisms [SNPs] different) and one, unexpectedly, matched the 2017 New Jersey patient’s isolate (1 SNP different). The two different RB51 strains were also shed from different quarters of cow 122’s udder. (It’s an old disease that won’t go away, like hockey players. This pic, left, is from about 2001 that my hockey pal Norm unearthed — he’s the coach in the middle, Bill and I were assistant coaches, daughter 2-of-4 beside me.)

Traceback revealed that cow 122 had received RB51 in 2011 and was purchased by dairy A in 2016. During 2016–2018, dairy A distributed raw milk potentially contaminated with RB51 to 19 states; PADOH notified those states’ public health veterinarians. PADOH provided a letter with RB51 information and brucellosis prophylaxis recommendations to the cooperative, which they distributed to dairy A customers. No additional cases were identified. Cow 122 was excluded from milk production, and serial PCR testing of bulk milk samples were subsequently negative for RB51.

Isolation of two different RB51 strains from different quarters of a cow’s udder has not previously been reported. These infections highlight the need to prevent RB51 infections. Raw milk consumption is also associated with serious illnesses caused by other pathogens, including Campylobacter spp., Shiga toxin–producing Escherichia coli, and Salmonella spp. (4). During 2007–2012, the number of raw milk outbreaks in the United States increased; 66 (81%) of 81 reported outbreaks occurred in states where raw milk sale is legal (5). Pregnant women, children, older adults, and persons with immunocompromising conditions are at greatest risk for infection.

To eliminate infection risk from milkborne pathogens, including RB51, all milk should be pasteurized. Because limited information is available about intermittent or continuous RB51 shedding among dairy cows, more research is needed to more fully understand this emerging public health threat for milk consumers. States can also consider the United States Animal Health Associations’ recommendations regarding the need for RB51 vaccination in areas where B. abortus is not endemic in wildlife.**

Notes from the field: Brucella abortus RB51 infections associated with consumption of raw milk from Pennsylvania—2017 and 2018, 17 April 2020

Morbidity and Mortality Weekly Report pp.482-483

Joann F. Gruber, PhD1,2; Alexandra Newman, DVM3; Christina Egan, PhD3; Colin Campbell, DVM4; Kristin Garafalo, MPH4; David R. Wolfgang, VMD5; Andre Weltman, MD2; Kelly E. Kline, MPH2; Sharon M. Watkins, PhD2; Suelee Robbe-Austerman, DVM, PhD6; Christine Quance6; Tyler Thacker, PhD6; Grishma Kharod, MPH1; Maria E. Negron, DVM, PhD1; Betsy Schroeder, DVM2

https://www.cdc.gov/mmwr/volumes/69/wr/mm6915a4.htm

The burden of norovirus

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Up-to-date estimates of the burden of norovirus, a leading cause of acute gastroenteritis (AGE) in the United States, are needed to assess the potential value of norovirus vaccines in development. We aimed to estimate the rates, annual counts, and healthcare charges of norovirus-associated ambulatory clinic encounters, Emergency Department (ED) visits, hospitalizations, and deaths in the United States.

Methods

We analyzed administrative data on AGE outcomes from July 1, 2001 through June 30, 2015. Data were sourced from IBM® MarketScan® Commercial and Medicare Supplemental Databases (ambulatory clinic and ED visits), the Healthcare Utilization Project National Inpatient Sample (NIS; hospitalizations), and the National Center for Health Statistics multiple-cause-of-mortality (MCM) data (deaths). Outcome data (ambulatory clinic and ED visits, hospitalizations, or deaths) were summarized by month, age group, and setting. Healthcare charges were estimated based on insurance claims. Monthly counts of cause-unspecified gastroenteritis-associated outcomes were modeled as functions of cause-specified outcomes, and model residuals were analyzed to estimate norovirus-associated outcomes. Healthcare charges were estimated by applying average charges per cause-unspecified gastroenteritis encounter to the estimated number of norovirus encounters.

Results

We estimate 900 deaths (95% Confidence Interval [CI]: 650 – 1100), 110,000 hospitalizations (95%CI: 80,000 – 145,000), 470,000 ED visits (95% CI: 348,000 – 610,000), and 2.3 million ambulatory clinic encounters (95% CI: 1.7 – 2.9 million) annually due to norovirus, with an associated $430 – 740 million in healthcare charges.

Conclusions

Norovirus causes a substantial health burden in the United States each year, and an effective vaccine could have important public health impact.

The burden of norovirus in the United States, as estimated based on administrative data: Updates for medically attended illness and mortality, 2001-2015, 14 April 2020

Clinical Infectious Diseases

Rachel M Burke, PhD, MPH, Claire Mattison, MPH, Talia Pindyck, MD, MPH, Rebecca M Dahl, MPH, Jessica Rudd, MPH, Daoling Bi, MS, Aaron T Curns, MPH, Umesh Parashar, MBBS, MPH, Aron J Hall, DVM, MSPH

https://doi.org/10.1093/cid/ciaa438

https://academic.oup.com/cid/article/doi/10.1093/cid/ciaa438/5820114

Vibrio and oysters: A review

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Vibrio parahaemolyticus is a Gram‐negative bacterium that is naturally present in the marine environment. Oysters, which are water filter feeders, may accumulate this pathogen in their soft tissues, thus increasing the risk of V. parahaemolyticus infection among people who consume oysters. In this review, factors affecting V. parahaemolyticus accumulation in oysters, the route of the pathogen from primary production to consumption, and the potential effects of climate change were discussed. In addition, intervention strategies for reducing accumulation of V. parahaemolyticus in oysters were presented.

A literature review revealed the following information relevant to the present study: (a) managing the safety of oysters (for human consumption) from primary production to consumption remains a challenge, (b) there are multiple factors that influence the concentration of V. parahaemolyticus in oysters from primary production to consumption, (c) climate change could possibly affect the safety of oysters, both directly and indirectly, placing public health at risk, (d) many intervention strategies have been developed to control and/or reduce the concentration of V. parahaemolyticus in oysters to acceptable levels, but most of them are mainly focused on the downstream steps of the oyster supply chain, and (c) although available regulation and/or guidelines governing the safety of oyster consumption are mostly available in developed countries, limited food safety information is available in developing countries. The information provided in this review may serve as an early warning for managing the future effects of climate change on the safety of oyster consumption.

Managing the risk of vibrio parahaemolyticus infections associated with oyster consumption: A review

Comprehensive Reviews in Food Science and Food Safety

Nodali Ndraha, Hin‐chung Wong, Hsin‐I Hsiao

https://doi.org/10.1111/1541-4337.12557

https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12557

Recall: E.coli O157 found in pepperoni product sold in Ireland

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Co-op Sliced Pepperoni, with a pack size of 70g, is subject to the food safety alert after the bacteria was found in one of its batches.

Escherichia coli (STEC), detected in the batch with a use by date of May 19, 2020, produces a powerful toxin which can cause “severe illness”.

The food safety chiefs said: “Co-op is recalling the above batch of its Sliced Pepperoni due to the detection of E.coli O157. 

“Point-of-sale recall notices will be displayed in stores supplied with the implicated batch.”

C. diff rates decline

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Efforts to prevent Clostridioides difficile infection continue to expand across the health care spectrum in the United States. Whether these efforts are reducing the national burden of C. difficile infection is unclear.

The Emerging Infections Program identified cases of C. difficile infection (stool specimens positive for C. difficile in a person ≥1 year of age with no positive test in the previous 8 weeks) in 10 U.S. sites. We used case and census sampling weights to estimate the national burden of C. difficile infection, first recurrences, hospitalizations, and in-hospital deaths from 2011 through 2017. Health care–associated infections were defined as those with onset in a health care facility or associated with recent admission to a health care facility; all others were classified as community-associated infections. For trend analyses, we used weighted random-intercept models with negative binomial distribution and logistic-regression models to adjust for the higher sensitivity of nucleic acid amplification tests (NAATs) as compared with other test types.

RESULTS

The number of cases of C. difficile infection in the 10 U.S. sites was 15,461 in 2011 (10,177 health care–associated and 5284 community-associated cases) and 15,512 in 2017 (7973 health care–associated and 7539 community-associated cases). The estimated national burden of C. difficile infection was 476,400 cases (95% confidence interval [CI], 419,900 to 532,900) in 2011 and 462,100 cases (95% CI, 428,600 to 495,600) in 2017. With accounting for NAAT use, the adjusted estimate of the total burden of C. difficile infection decreased by 24% (95% CI, 6 to 36) from 2011 through 2017; the adjusted estimate of the national burden of health care–associated C. difficileinfection decreased by 36% (95% CI, 24 to 54), whereas the adjusted estimate of the national burden of community-associated C. difficile infection was unchanged. The adjusted estimate of the burden of hospitalizations for C. difficile infection decreased by 24% (95% CI, 0 to 48), whereas the adjusted estimates of the burden of first recurrences and in-hospital deaths did not change significantly.

CONCLUSIONS

The estimated national burden of C. difficile infection and associated hospitalizations decreased from 2011 through 2017, owing to a decline in health care–associated infections. (Funded by the Centers for Disease Control and Prevention.)

Trends in US burden of clostridioides difficile infection and outcomes, 02 April 2020

New England Journal of Medicine

Alice Y. Guh, M.D., M.P.H., Yi Mu, Ph.D., Lisa G. Winston, M.D., Helen Johnston, M.P.H., Danyel Olson, M.S., M.P.H., Monica M. Farley, M.D., Lucy E. Wilson, M.D., Stacy M. Holzbauer, D.V.M., M.P.H., Erin C. Phipps, D.V.M., M.P.H., Ghinwa K. Dumyati, M.D., Zintars G. Beldavs, M.S., Marion A. Kainer, M.B., B.S., M.P.H., Maria Karlsson, Ph.D., Dale N. Gerding, M.D., and L. Clifford McDonald, M.D.

DOI: 10.1056/NEJMoa1910215

https://www.nejm.org/doi/10.1056/NEJMoa1910215