Multistate Outbreak of Salmonella Virchow Infections Linked to a Powdered Meal Replacement Product-United States, 2015-2016

A review of food safety in low-moisture foods with current and potential dry-cleaning methods

Food is one of the basic needs of human life. With the increasing population, the production and supply of safe and quality foods are critical. Foods can be classified into different categories including low moisture, intermediate moisture, and high moisture content. Historically, low-moisture foods have been considered safe for human consumption due to the limited amount of moisture for microbial activity. Recalls of these foods due to pathogens such as Salmonella and undeclared allergens have brought attention to the need for improved cleaning and sanitization in dry food manufacturing facilities. In the food industry, cleaning and sanitation activities are the most efficient methods to prevent microbial contamination; however, water is most often required to deliver cleaning and sanitation agents. A well-written and properly implemented sanitation standard operating procedure can take care of microbial and allergen cross-contamination. Nevertheless, there are unique challenges to cleaning and sanitation processes for low-moisture food manufacturing facilities. The introduction of moisture into a low-moisture food environment increases the likelihood of cross-contamination by microbial pathogens. Hence, the use of water during cleaning and sanitation of dry food manufacturing facilities should be limited. However, much less research has been done on these dry methods compared to wet sanitation methods. This review discusses recent foodborne outbreaks and recalls associated with low-moisture foods the accepted methods for cleaning and sanitation in dry food manufacturing facilities and the limitations of these methods. The potential for air impingement as a dry-cleaning method is also detailed.

Pasteurization of Salmonella spp. in black fungus (Auricularia auricula) powder by radio frequency heating

Radio frequency (RF) heating has been studied to inactivate bacteria in some powder foods. In this study, a 6 kW, 27.12 MHz RF system was used to pasteurize Salmonella in black fungus (Auricularia auricula) powder. The effects of different conditions (initial aw, electrodes gaps, particle sizes) on RF heating rate and uniformity were investigated. The results showed that RF heating rate was significantly (p < 0.05) improved with decreasing electrodes gap and increasing initial aw, and the heating rate was the slowest when the particle size was 120-160 mesh. However, these factors had no significant (p > 0.05) influence on heating uniformity. RF pasteurization of Salmonella in black fungus powder was also studied. The results showed that, to inactivate Salmonella for 5 log reductions in the cold spot (the center of surface layer), the time needed and bacteria heat resistance at designated temperature (65, 75, 85 °C) decreased with increasing aw, and the first order kinetics and Weibull model could be used to fit inactivation curves of Salmonella with well goodness. Quality analysis results showed that although RF pasteurization had no significant (p > 0.05) effect on Auricularia auricula polysaccharide (AAP) and total polyphenols, obvious changes were found on color. Results suggested that RF pasteurization can be considered as an effective pasteurization method for black fungus powder.

A Multiple-Serotype Outbreak of Salmonella Infections Linked to Kratom, United States, 2017-2018

In early 2018, we investigated a large national multiple-serotype Salmonella outbreak linked to contaminated kratom, a raw minimally processed botanical substance. Kratom is a plant consumed for its stimulant effects and as an opioid substitute. A case was defined as a laboratory-confirmed Salmonella infection with one of the outbreak strains (serotypes I 4,[5],12:b:-, Heidelberg, Javiana, Okatie, Weltevreden, or Thompson) with illnesses onset during January 11, 2017-May 8, 2018. State and local officials collected detailed information on product consumption and sources. Suspected products were tested for Salmonella and traceback was conducted to determine product distribution chains and suppliers. We identified 199 cases from 41 states; 54 patients were hospitalized. Early interviews indicated kratom was an exposure of interest. Seventy-six (74%) of 103 people interviewed reported consuming kratom in pills, powders, or teas. Multiple serotypes of Salmonella were detected in samples of kratom collected from the homes of the patients and from retail locations. Several companies issued recalls of kratom products due to Salmonella contamination. To the authors' knowledge, this investigation is the first to establish kratom as a vehicle for Salmonella infection. Our findings underscore the serious safety concerns regarding minimally processed botanical substances intended for oral consumption and the challenges in investigating outbreaks linked to novel outbreak vehicles.

Text Mining Approaches for Postmarket Food Safety Surveillance Using Online Media

Food contamination and food poisoning pose enormous risks to consumers across the world. As discussions of consumer experiences have spread through online media, we propose the use of text mining to rapidly screen online media for mentions of food safety hazards. We compile a large data set of labeled consumer posts spanning two major websites. Utilizing text mining and supervised machine learning, we identify unique words and phrases in online posts that identify consumers' interactions with hazardous food products. We compare our methods to traditional sentiment-based text mining. We assess performance in a high-volume setting, utilizing a data set of over 4 million online reviews. Our methods were 77-90% accurate in top-ranking reviews, while sentiment analysis was just 11-26% accurate. Moreover, we aggregate review-level results to make product-level risk assessments. A panel of 21 food safety experts assessed our model's hazard-flagged products to exhibit substantially higher risk than baseline products. We suggest the use of these tools to profile food items and assess risk, building a postmarket decision support system to identify hazardous food products. Our research contributes to the literature and practice by providing practical and inexpensive means for rapidly monitoring food safety in real time.

Multijurisdictional Outbreak of Enterohemorrhagic Escherichia coli O157 Caused by Consumption of Ready-to-Eat Grilled Skewered Meat in Niigata, Japan

Enterohemorrhagic Escherichia coli O157 (EHEC) causes severe complications such as hemolytic uremic syndrome. Contaminated ready-to-eat (RTE) food is one of the vehicles of multijurisdictional outbreaks of foodborne disease worldwide. Multijurisdictional (covering cities, towns, and villages) outbreaks of EHEC are usually linked to an increase in cases, and here we describe such an outbreak involving 29 cases in October 2017 in the Niigata Prefecture. After prefecture-wide active case finding, we conducted a case-control study of 29 cases with eligible data who tested positive for EHEC. To determine the association of the outbreak with risk factors, we compared these cases with 38 controls selected from family and acquaintances who were both symptom free and tested negative for EHEC. The largest number of cases was in the 20-29-year age group (7/29; 24%) and most were women (20/29; 69%). All 29 cases had an identical or similar multilocus variable number tandem-repeat analysis (MLVA) profile. Of these, 76% (22/29) had consumed some type of grilled skewered meat. Also, 69% (20/29) had consumed grilled skewered meat produced by company X. EHEC infection was strongly associated with the consumption of grilled skewered meat produced by any food processing company (odds ratio [OR] = 11.8, confidence interval [95% CI]: 3.7-37.4) and by company X (OR = 9.8, 95% CI: 3.2-30.7). At company X, the skewered meat was grilled to 95°C and then removed from the grilling area to meat trays. The meat trays were not sufficiently washed and disinfected. Testing indicated that the facility was negative for EHEC but four asymptomatic employees tested positive for EHEC. Company X was temporarily closed and voluntarily recalled the foods. We recommend that all employees sufficiently wash and disinfect meat trays to prevent contamination of RTE food, avoid cross-contamination of grilled skewered meat through the environment by regularly cleaning the facility, and appropriately practice self-health care.

Effect of Moringa oleifera leaf extract on exercise and dexamethasone-induced functional impairment in skeletal muscles

Background

Chronic administration of steroids like dexamethasone produces symptoms including weight loss and skeletal muscle dysfunction. Similar events are reported in chronic or high-intensity exercises, that can lead to fatigue and muscle damage.

Objective

In the present study, the effect of Moringa oleifera leaf extract was evaluated against dexamethasone (Dex) and exercise (Exe)-induced muscle changes in rats.

Materials and methods

Six groups each containing 6 rats, namely normal, Dex control, Exe Control, Dex + M. oleifera leaf extract (300mg/kgp.o.), Dex + Exe, Dex + Exe + M. oleifera leaf extract were assessed in the study. Dex was administered at 0.6 mg/kg i.p. daily for 7 days. Exercise was given for a total of 10 days after 30 minutes of dosing using treadmill equipment for 900 seconds at speed 18 m/min. Animals were assessed for variation in body weight, muscular endurance using treadmill, locomotor activity using actophotometer, motor coordination using rotarod on day zero, and day seven. Hemidiaphragm of rats were isolated and used for evaluation of the glucose uptake. Gastrocnemius muscle was isolated and subjected to hematoxylin and eosin staining.

Results

Dex and Exe control animals showed a significant decrease in skeletal muscle activity when compared to normal control animals in the actophotometer test. Improvement in endurance were seen in Dex + M. oleifera leaf extract, and Dex + exercise + M. oleifera leaf extract groups compared to Dex control group. Improvement in locomotor activity was seen in Dex group subjected to exercise and was significant when treated with M. oleifera leaf extract. Histology reports were in accordance with the functional parameters.

Conclusion

M. oleifera leaf extract supplemented with exercise showed a reversal in the dexamethasone-induced functional impairment in skeletal muscles.

Hypothesis Generation During Foodborne-Illness Outbreak Investigations

Hypothesis generation is a critical, but challenging, step in a foodborne outbreak investigation. The pathogens that contaminate food have many diverse reservoirs, resulting in seemingly limitless potential vehicles. Identifying a vehicle is particularly challenging for clusters detected through national pathogen-specific surveillance, because cases can be geographically dispersed and lack an obvious epidemiologic link. Moreover, state and local health departments could have limited resources to dedicate to cluster and outbreak investigations. These challenges underscore the importance of hypothesis generation during an outbreak investigation. In this review, we present a framework for hypothesis generation focusing on 3 primary sources of information, typically used in combination: 1) known sources of the pathogen causing illness; 2) person, place, and time characteristics of cases associated with the outbreak (descriptive data); and 3) case exposure assessment. Hypothesis generation can narrow the list of potential food vehicles and focus subsequent epidemiologic, laboratory, environmental, and traceback efforts, ensuring that time and resources are used more efficiently and increasing the likelihood of rapidly and conclusively implicating the contaminated food vehicle.

Population-based food consumption survey as an additional tool for foodborne outbreak investigations, Germany, 2017

We conducted a food consumption survey in the general adult population of 18 years and older in Germany to obtain data on the frequency of consumption of food items that caused foodborne disease outbreaks in the past. A total of 1010 telephone interviews were completed that queried the consumption of 95 food items in the 7-day period before the interview. Survey results were weighted to be representative. Six exemplary 'high risk' food items were consumed by 6% to 16% of the general population. These were raw ground pork: 6.5%; 'Teewurst' (=spreadable sausage-containing raw pork): 15.7%; unpasteurised milk consumed without prior heating: 9.0%; food items prepared with raw eggs: 9.8%; unheated sprouts or seedlings: 8.8% and frozen berries consumed without prior heating: 6.2%. Data from our food consumption survey were comparable to data obtained from control persons in case-control studies conducted during past foodborne disease outbreak investigations. We consider our survey an additional helpful tool that will allow comparison with food consumption data from case-patients obtained in exploratory, hypothesis-generating interviews early on in outbreak investigations, and which may assist in forming hypotheses regarding associations of illnesses with suspected food vehicles. This may facilitate and accelerate investigations of future foodborne disease outbreaks.

Prevalence of Multidrug Resistant Salmonellae with Increasing Frequency of Salmonella enterica Serovars Kentucky and Virchow among Hospitalized Diarrheal Cases in and around Delhi, India

Non-typhoidal salmonellae (NTS) are a major cause of acute diarrhea with characteristic multidrug resistance (MDR). In a hospital-based study, 81 NTS were isolated and tested for serotypes and antimicrobial resistance (AMR). Salmonella enterica isolates were classified into 7 different typable serovars, however, 19 (23%) isolates remained untypable. The most common serovars were S. Kentucky (48%), and S. Virchow (22%). Most of the NTS isolates displayed resistance to nalidixic acid (NA) (73%), ciprofloxacin (CIP) (48%), ampicillin (AM) and norfloxacin (NOR) (36% each), and gentamicin (CN) (31%). The AMR profiles for CN and NA; and AM, CIP, NA and NOR, were found to be high in S. Virchow (83%) and S. Kentucky (43%), respectively. Analysis of the pulsed-field gel electrophoresis patterns of S. Kentucky revealed 3 clusters. S. Kentucky has clones closely related to become prominent in recent years in Delhi. The AMR appears to be consistent with the change in MDR patterns during 2014-2017. The observed prevalence of S. Kentucky and S. Virchow in large numbers of diarrheal cases is novel. The NTS are mostly resistant to fluoroquinolones, which is the current drug of choice for treating diarrheal cases. MDR is very common among clonally related S. Kentucky.

A Multistate Outbreak of E Coli O157:H7 Infections Linked to Soy Nut Butter

BACKGROUND

In 2017, we conducted a multistate investigation to determine the source of an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infections, which occurred primarily in children.

METHODS

We defined a case as infection with an outbreak strain of STEC O157:H7 with illness onset between January 1, 2017, and April 30, 2017. Case patients were interviewed to identify common exposures. Traceback and facility investigations were conducted; food samples were tested for STEC.

RESULTS

We identified 32 cases from 12 states. Twenty-six (81%) cases occurred in children <18 years old; 8 children developed hemolytic uremic syndrome. Twenty-five (78%) case patients ate the same brand of soy nut butter or attended facilities that served it. We identified 3 illness subclusters, including a child care center where person-to-person transmission may have occurred. Testing isolated an outbreak strain from 11 soy nut butter samples. Investigations identified violations of good manufacturing practices at the soy nut butter manufacturing facility with opportunities for product contamination, although the specific route of contamination was undetermined.

CONCLUSIONS

This investigation identified soy nut butter as the source of a multistate outbreak of STEC infections affecting mainly children. The ensuing recall of all soy nut butter products the facility manufactured, totaling >1.2 million lb, likely prevented additional illnesses. Prompt diagnosis of STEC infections and appropriate specimen collection aids in outbreak detection. Child care providers should follow appropriate hygiene practices to prevent secondary spread of enteric illness in child care settings. Firms should manufacture ready-to-eat foods in a manner that minimizes the risk of contamination.