Prevalence, serotype, and antimicrobial resistance of Salmonella on broiler carcasses postpick and postchill in 20 U.S. processing plants.

The objective of this study was to measure the effect of broiler processing on the prevalence, serotype, and antimicrobial resistance profiles of salmonellae. Twenty U.S. commercial processing plants representing eight integrators in 13 states were included in the survey. In each of four replications, 10 carcasses from one flock were collected at rehang and 10 more carcasses were collected at postchill; each carcass was sampled by whole-carcass rinse. Salmonella organisms were isolated from carcass rinses by standard cultural techniques, serotypes were determined, and the resistance to 15 antimicrobials was measured. Overall, Salmonella was detected on 72% of carcasses at rehang (ranging from 35 to 97%) and on 20% of carcasses postchill (ranging from 2.5 to 60%). In every instance, a significant (P < 0.05) decrease in Salmonella prevalence was noted between rehang and postchill. The four most common serotypes, accounting for 64% of all Salmonella isolates, were Kentucky, Heidelberg, Typhimurium, and Typhimurium var. 5-; most isolates of Kentucky (52%), Heidelberg (79%), and Typhimurium (54%) serotypes were susceptible to all antimicrobial drugs tested. However, only 15% of the Typhimurium var. 5- isolates were pansusceptible; more than one-half of the isolates of this serotype were resistant to three or more drugs. No isolate of any serotype exhibited resistance to amikacin, ceftriaxone, ciprofloxacin, or trimethoprim-sulfamethoxazole. These data demonstrate that although processing lessens carcass contamination with Salmonella, antimicrobial-resistant isolates may still be present.

Assessment of post-Hurricane Katrina recovery in poultry slaughter establishments.

Control of bacterial contamination during poultry slaughter can be compromised by natural disaster. In October 2005, disaster recovery was evaluated in 11 broiler slaughter establishments 1 month after operations were disrupted by Hurricane Katrina. A questionnaire was administered to characterize the establishment's operational disruption. Carcass rinses were collected at the early and late stage of the slaughter process (rehang and postchill). Counts for generic Escherichia coli were determined for all rinses. Salmonella culture and serotyping were performed on postchill samples. Historical U.S. Food Safety and Inspection Service data on the presence of Salmonella also were examined. The mean duration of disruption was 6.3 days (range, 3 to 9 days). Loss of utilities (electricity and water) was the cause of prolonged recoveries. Most establishments (64%) did not exceed the m performance criteria threshold for generic E. coli (>2 log or 100 CFU/ml) during the recovery period. The mean reduction in E. coli counts between rehang and postchill was 2.3 log or 200 CFU/ml (range, 0.9 to 3.1 log CFU/ ml). Rinse samples from 5 of 11 establishments were positive for Salmonella. Of 12 Salmonella isolates that were recovered, eight were Salmonella Kentucky. Salmonella Heidelberg and Salmonella Thompson were recovered from one establishment, and two isolates of Salmonella Typhimurium were isolated from another. This study provided empirical reassurance that the establishments' processes controlled bacterial contamination. Data on reductions in E. coli counts during poultry slaughter may help establishments control microbial contamination. Other data (e.g., Salmonella and Campylobacter enumeration) may also have merit for this purpose.

Prevalence and numbers of Campylobacter on broiler carcasses collected at rehang and postchill in 20 U.S. processing plants.

Campylobacter is a human pathogen associated with chicken and chicken meat products. This study was designed to examine the prevalence and number of Campylobacter on broiler chicken carcasses in commercial processing plants in the United States. Carcass samples were collected from each of 20 U.S. plants four times, roughly approximating the four seasons of 2005. At each plant on each sample day, 10 carcasses were collected at rehang (prior to evisceration), and 10 carcasses from the same flock were collected postchill. A total of 800 carcasses were collected at rehang and another 800 were collected postchill. All carcasses were subjected to a whole-carcass rinse, and the rinse diluent was cultured for Campylobacter. The overall mean number of Campylobacter detected on carcasses at rehang was 2.66 log CFU per ml of carcass rinse. In each plant, the Campylobacter numbers were significantly reduced by broiler processing; the mean concentration after chill was 0.43 log CFU/ml. Overall prevalence was also reduced by processing from a mean of > or =30 of 40 carcasses at rehang to > or =14 of 40 carcasses at postchill. Seven different on-line reprocessing techniques were applied in the test plants, and all techniques resulted in <1 log CFU/ml after chilling. Use of a chlorinated carcass wash before evisceration did not affect the postchill Campylobacter numbers. However, use of chlorine in the chill tank was related to lower numbers on postchill carcasses. Overall, U.S. commercial poultry slaughter operations are successful in significantly lowering the prevalence and number of Campylobacter on broiler carcasses during processing.

Hair dye use and risk of fatal cancers in U.S. women.

BACKGROUND: Permanent hair dyes are used by about one third of adult American women. Several epidemiologic studies associate hair dye use with increased risk of non-Hodgkin's lymphoma and multiple myeloma. In one study, risk increased with more prolonged exposure to darker, more concentrated, permanent dyes. PURPOSE: The purpose of our study was to examine the relationship between hair dye use and development of certain cancers associated with hair dye use in previous studies. METHODS: We examined prospectively the relationship between the use of permanent hair dyes and selected fatal cancers in 573,369 women. The participants provided information in 1982 on the frequency and duration of hair dye use and the color of hair dye used. Death rates were measured through 1989. Relative risks (RRs) were computed with subjects who had not used hair dyes serving as the referent group, and 95% confidence intervals (CIs) were calculated on the basis of approximate-variance formulas. RESULTS: Women who had ever used permanent hair dyes showed decreased risk of all fatal cancers combined (RR = 0.93; 95% CI = 0.89-0.98) and of urinary system cancers (RR = 0.65; 95% CI = 0.49-0.87) and no increase in risk of any type of hematopoietic cancer. Women who had used black hair dyes for 20 years (0.6% of women hair dyers) or more had increased risk of fatal non-Hodgkin's lymphoma (RR = 4.37; 95% CI = 1.3-15.2) and multiple myeloma (RR = 4.39; 95% CI = 1.1-18.3). These positive findings are based on three cases of non-Hodgkin's lymphoma and two cases of multiple myeloma. We found no relationship between use of permanent hair dyes and fatal cancers of the mouth, breast, lung, bladder, or cervix, areas that were of interest as the result of earlier studies. CONCLUSIONS: Women using permanent hair dyes are not generally at increased risk of fatal cancer. Women with prolonged use of dark, particularly black, hair dyes may have increased risk of fatal non-Hodgkin's lymphoma and multiple myeloma, but these women are a small fraction of hair dye users. Nonetheless, the removal of carcinogens from hair dyes and appropriate labeling of hair-coloring products would help reduce this potential risk.

Foodborne diseases. Emerging pathogens and trends.

The epidemiology of foodborne diseases is rapidly changing. In the past 15 years, new foodborne pathogens, such as Campylobacter jejuni and Escherichia coli O157:H7, have emerged as important public health problems. Well-recognized pathogens, such as Salmonella serotype Enteritidis, have increased in prevalence or become associated with new vehicles, and pathogens such as C. jejuni and S. Typhimurium are becoming increasingly resistant to antimicrobial agents. Evolving trends in foodborne diseases are being driven by the same factors that have led to the emergence of other infectious diseases: changes in demographic characteristics of the population, human behavior, industry, and technology and the shift toward a global economy, microbial adaptation, and breakdown in the public health infrastructure. Addressing emerging foodborne disease will require more sensitive and timely surveillance, enhanced methods of laboratory identification and subtyping, and identification of effective prevention and control strategies.

Raw shellfish consumption in California: the 1992 California Behavioral Risk Factor Survey.

We used the 1992 California Behavioral Risk Factor Surveillance System to study the prevalence of raw shellfish consumption in California and the demographic and behavioral characteristics of raw shellfish consumers. We used the logistic regression analysis of the weighted survey data with PC SAS and SUDAAN to adjust for the effects of age and gender. Twenty-three percent of the respondents in the survey reported that they ate raw shellfish; one third of these reported eating raw shellfish once a month. Higher prevalences of raw shellfish consumption were reported by men, persons 18-49 years old, those with income above $25,000 and education beyond high school than by women, individuals older than 49 years, and those with an income of $25,000 or less per year and 12 or fewer years of school. A higher percentage of persons with liver disease, stomach surgery, and a history of chronic alcohol drinking reported consumption of raw shellfish than did individuals without liver disease, previous stomach surgery, or a history of alcohol abuse. After adjustment for gender and age, those who reported acute (P < .01) and chronic (P < .01) drinking and driving while intoxicated (P < .01) were more likely to report consumption of raw shellfish. Two variables (lack of seat belt usage [P = 2] and cigarette smoking [P = .13]) were not significantly associated statistically with raw shellfish consumption.

A multi-state survey of consumer food-handling and food-consumption practices.

INTRODUCTION: In the United States, foodborne infections cause an estimated 6.5-33 million illnesses a year. Also included in the burden of foodborne illnesses are sequelae such as hemolytic uremic syndrome, Guillain-Barré syndrome, and reactive arthritis. Surveillance for risky food-handling and food-consumption practices can be used to identify high-risk populations, develop educational efforts, and evaluate progress toward risk reduction. DESIGN: In 1995 and 1996, Behavioral Risk Factor Surveillance System interviews of 19,356 adults in eight states (1995: Colorado, Florida, Missouri, New York, and Tennessee; 1996: Indiana, New Jersey, and South Dakota) included questions related to food-handling and/or food-consumption practices. Risky food-handling and food-consumption practices were not uncommon. Overall, 19% of respondents did not adequately wash hands or cutting boards after contact with raw meat or chicken. During the previous year, 20% ate pink hamburgers, 50% ate undercooked eggs, 8% ate raw oysters, and 1% drank raw milk. Men were more likely to report risky practices than women. The prevalence of most risky behaviors increased with increasing socioeconomic status. CONCLUSION: Targeted education efforts may reduce the frequency of these behaviors. Periodic surveillance can be used to assess effectiveness. In addition to consumer education, prevention efforts are needed throughout the food chain including on the farm, in processing, distribution, and at retail.

The changing epidemiology of foodborne diseases.

The epidemiology of foodborne diseases in the United States have changed in recent decades as new pathogens have emerged, the food supply has changed, and the number of people with heightened susceptibility to foodborne diseases has increased. Emerging pathogens are those that have recently increased or are likely to increase within 2 decades. Emergency is often the consequence of changes in some aspect of the social environment. The global economy, for example, has facilitated the rapid transport of perishable foods, increasing the potential for exposure to foodborne pathogens from other parts of the world. Other factors altering foodborne disease patterns are the types of food that people eat, the sources of those foods, and the possible decline in public awareness of safe food preparation practices. Aging, extension of life expectancy for the chronically ill through medical technology, and the AIDS epidemic have increased the public health impact of foodborne diseases because they increase the proportion of the population susceptible to severe illness after infection with a foodborne pathogen. The evolving epidemiology of foodborne diseases must be monitored and understood to implement appropriate prevention technologies.

Evaluation of safe food-handling instructions on raw meat and poultry products.

Every year in the United States, millions of people become ill, thousands of people die, and substantial economic costs are incurred from foodborne diseases. As a measure to prevent foodborne diseases, since July 1994, the U.S. Department of Agriculture has required that safe food-handling labels be placed on retail packages of raw or partially cooked meat and poultry products. Through selected states' Behavioral Risk Factor Surveillance System (BRFSS) interviews, survey data were collected to determine the proportion of adults aware of the label and adults who reported changing their raw meat-handling practices because of the label. Fifty-one percent of the 14,262 respondents reported that they had seen the label. Of these, 79% remembered reading the label, and 37% of persons who reported that they had seen and read the label reported changing their raw meat preparation methods because of the label. Women were more likely than men to have read the label, as were persons who are at least 30 years of age compared to younger adults (P < 0.05). Both label awareness and risky food-handling behaviors increased with education and income, suggesting that safe food-handling labels have limited influence on consumer practices. Our results also suggest that the labels might be more effective in discouraging cross-contamination than in promoting thorough cooking practices. We suggest that the label is only one component among many food safety education programs that are needed to inform consumers about proper food-handling and preparation practices and to motivate persons who have risky food-handling and preparation behaviors to change these behaviors.

Consumer knowledge of foodborne microbial hazards and food-handling practices.

A national telephone survey was conducted of 1,620 randomly selected U.S. residents who spoke English, were at least 18 years old, and resided in households with kitchen facilities. Respondents were interviewed about their recognition of foodborne pathogens, foods at risk for transmitting infection, knowledge of safe food handling, and food-handling practices. One-third of the respondents who prepared meals reported unsafe food hygiene practices: e.g., they did not wash hands or take precautions to prevent cross-contamination from raw meat. Unsafe practices were reported more often by men, adults 18 to 29 years of age, and occasional food preparers than by women, persons 30 years old or older, and frequent food preparers. Respondents who identified a food vehicle for Salmonella spp. were more likely to report washing their hands and cleaning cutting boards after preparing raw meat and poultry. The results raise concerns about consumer food-handling practices. The influence of food safety training, food-handling experience, and age on food-handling practices should be studied further. Awareness of a food vehicle for Salmonella spp., for example, may indicate knowledge of the etiology of foodborne disease that promotes safe food handling. Understanding the factors associated with safe food handling will assist in development of effective safe-food instruction programs.

Cheese-associated outbreaks of human illness in the United States, 1973 to 1992: sanitary manufacturing practices protect consumers.

To identify contributing factors for cheese-associated outbreaks, we reviewed all cheese-associated outbreaks of human illness reported to the Centers for Disease Control and Prevention (CDC) with onsets during 1973 to 1992. The infrequency of large, cheese-associated outbreaks was notable because such outbreaks had been a frequent public health problem before the mid-20th century. Of 32 reported cheese-associated outbreaks, 11 attributed to manufacturing errors caused most of the illnesses and hospitalizations and all 58 deaths. Important factors in these 11 outbreaks were manufacturing cheese with raw or improperly pasteurized milk and postpasteurization contamination. If current Food and Drug Administration sanitary requirements for cheesemaking had been met, these outbreaks would have been preventable. In two outbreaks of Salmonella infections, fewer than 10 Salmonella per 100 g of cheese were detected. In two outbreaks of Brucella infections, efforts to recover the pathogen from the implicated cheese were unsuccessful, emphasizing the inadequacy of end product testing for assuring consumer safety. Curing cheeses kills most bacteria present in cheeses; however, evidence from sources other than the CDC Foodborne Disease Outbreak Surveillance System suggests that curing alone may not be a sufficient pathogen control step to eliminate Salmonella, Listeria, and E. coli O157:H7 from cheese.

Pathogenic and fecal Escherichia coil strains from turkeys in a commercial operation.

The biochemical phenotypes and antimicrobial susceptibility patterns of 105 clinical Escherichia coli isolates from flocks with colibacillosis in a turkey operation were compared with 1104 fecal E. coli isolates from 20 flocks in that operation. Clinical isolates and 194 fecal isolates with biochemical phenotypes or minimum inhibitory concentrations for gentamicin and sulfamethoxazole similar to clinical isolates were tested for somatic antigens and the potential virulence genes hylE, iss, tsh, and K1. The predominant biochemical phenotype of clinical isolates contained 21 isolates including 14 isolates belonging to serogroup 078 with barely detectable beta-D-glucuronidase activity. Thirty-five fecal isolates had biochemical phenotypes matching common phenotypes of clinical isolates. Sixty-six (63%) clinical isolates exhibited intermediate susceptibility or resistance to gentamicin and sulfamethoxazole compared with 265 (24%) fecal isolates (P < 0.001). Seventy-seven clinical isolates reacted with O-antisera, of which 51 (66%) belonged to the following serogroups: O1, O2, O8, O25, O78, O114, and O119. In comparison, 8 of 35 (23%) fecal isolates subtyped on the basis of biochemical phenotype belonged to these serogroups and four of 167 (2%) fecal isolates subtyped on the basis of their antimicrobial resistance patterns belonged to these serogroups. Iss, K1, and tsh genes were detected more often among clinical isolates than these fecal isolates (P < 0.05). In summary, a small subgroup of E. coli strains caused most colibacillosis infections in this operation. These strains existed at low concentration in normal fecal flora of healthy turkeys in intensively raised flocks. The data suggest that colibacillosis in turkey operations may be due to endogenous infections caused by specialized pathogens.

Therapeutic antibiotics in animal feeds and antibiotic resistance.

Recent statutory changes involving animal drugs are expected to facilitate the therapeutic use of antibiotics in animal feeds in the United States of America. The use of antibiotics in animal feeds is controversial due to the potential development of resistant bacterial pathogens in food-producing animals which are exposed to the antibiotics and the resultant public health risk. Zoonotic micro-organisms can be transmitted to humans through contact with animal populations, either directly or through the consumption of contaminated food. Recommendations to address the public health concerns include the strengthening of professional education in the areas of infectious diseases and the appropriate selection and use of antimicrobial agents, the development of a comprehensive food safety education programme for food-animal veterinarians and animal producers, and the development of surveillance programmes to monitor antimicrobial resistance among zoonotic pathogens. Early identification of emerging resistance can facilitate a timely and appropriate public health response.

Factors in the emergence of food borne diseases.

Food borne diseases are an important public health problem. Over the past two decades, the epidemiology of food borne diseases has changed rapidly as a consequence of changes in the social environment and the ability of pathogens to adapt to new niches. Several newly recognized pathogens have emerged and well-recognized pathogens have increased in prevalence or become associated with new food vehicles. Several factors have contributed to the changing patterns of food borne diseases, and addressing food borne diseases will require rapid surveillance and effective prevention strategies. This article examines these factors and briefly addresses prevention and control of food borne diseases.

Microbial food borne pathogens. Campylobacter jejuni.

Campylobacter jejuni is the most common food borne bacterial pathogen and leading cause of food borne disease in humans in the United States and other industrialized nations. Approximately four million cases of human campylobacteriosis occur each year in the United States. Although the majority of cases consist of limited diarrheal illness, severe sequelae can affect a small portion of patients with campylobacteriosis that may include reactive arthritis and Guillain-Barré syndrome. Animal reservoirs primarily include poultry (C. jejuni) and swine (C. coli). Pathogen reduction during poultry processing and safe handling of raw poultry in the kitchen are needed to prevent illness.