This study investigated cases of pregnancy-related listeriosis in British Columbia (BC), Canada, from 2005 to 2014. We described all diagnosed cases in pregnant women (n = 15) and neonates (n = 7), estimated the excess healthcare costs associated with listeriosis, and calculated the fraction of stillbirths attributable to listeriosis, and mask cell sizes 1–5 due to data requirements. Pregnant women had a median gestational age of 31 weeks at listeriosis onset (range: 20–39) and on average delivered at a median of 37 weeks gestation (range: 20–40). Neonates experienced complications but no fatalities. Stillbirths occurred in 1–5 of 15 pregnant women with listeriosis, and very few (0.05–0.24%) of the 2,088 stillbirths in BC in the 10 years were attributed to listeriosis (exact numbers masked). Pregnant women and neonates with listeriosis had significantly more hospital visits, days in the hospital and physician visits than those without listeriosis. Pregnant women with listeriosis had 2.59 times higher mean total healthcare costs during their pregnancy, and neonates with listeriosis had 9.85 times higher mean total healthcare costs during their neonatal period, adjusting for various factors. Despite small case numbers and no reported deaths, these results highlight the substantial additional health service use and costs associated with individual cases of pregnancy-related listeriosis in BC.

Many articles have summarized the changing epidemiology of Clostridium difficile infections (CDI) in humans, but the emerging presence of C. difficile in foods and animals and possible measures to reduce human exposure to this important pathogen have been infrequently addressed. CDIs have traditionally been assumed to be restricted to health-care settings. However, recent molecular studies indicate that this is no longer the case; animals and foods might be involved in the changing epidemiology of CDIs in humans; and genome sequencing is disproving person-to-person transmission in hospitals. Although zoonotic and foodborne transmission have not been confirmed, it is evident that susceptible people can be inadvertently exposed to C. difficile from foods, animals, or their environment. Strains of epidemic clones present in humans are common in companion and food animals, raw meats, poultry products, vegetables, and ready-to-eat foods, including salads. In order to develop science-based prevention strategies, it is critical to understand how C. difficile reaches foods and humans. This review contextualizes the current understanding of CDIs in humans, animals, and foods. Based on available information, we propose a list of educational measures that could reduce the exposure of susceptible people to C. difficile. Enhanced educational efforts and behavior change targeting medical and non-medical personnel are needed.

Food-borne intoxication, caused by heat-stable enterotoxins produced by Staphylococcus aureus, causes over 240,000 cases of food-borne illness in the United States annually. Other staphylococci commonly associated with animals may also produce these enterotoxins. Foods may be contaminated by infected food handlers during slaughter and processing of livestock or by cross-contamination during food preparation. S. aureus also causes a variety of mild to severe skin and soft tissue infections in humans and other animals. Antibiotic resistance is common in staphylococci. Hospital-associated (HA) S. aureus are resistant to numerous antibiotics, with methicillin-resistant S. aureus (MRSA) presenting significant challenges in health care facilities for over 40 years. During the mid-1990s new human MRSA strains developed outside of hospitals and were termed community-associated (CA). A few years later, MRSA was isolated from horses and methicillin resistance was detected in Staphylococcus intermedius/pseudintermedius from dogs and cats. In 2003, a livestock-associated (LA) MRSA strain was first detected in swine. These methicillin-resistant staphylococci pose additional food safety and occupational health concerns. MRSA has been detected in a small percentage of retail meat and raw milk samples indicating a potential risk for food-borne transmission of MRSA. Persons working with animals or handling meat products may be at increased risk for antibiotic-resistant infections. This review discusses the scope of the problem of methicillin-resistant staphylococci and some strategies for control of these bacteria and prevention of illness.

Microsporidia are spore-forming intracellular parasites that infrequently cause disease in immunocompetent persons. This study describes the first report of a foodborne microsporidiosis outbreak which affected persons visiting a hotel in Sweden. Enterocytozoon bieneusi was identified in stool samples from 7/11 case-patients, all six sequenced samples were genotype C. To confirm that this was not a chance finding, 19 stool samples submitted by healthy persons from a comparable group who did not visit the hotel on that day were tested; all were negative for microsporidia. A retrospective cohort study identified 135 case-patients (attack rate 30%). The median incubation period was 9 days. Consumption of cheese sandwiches [relative risk (RR) 4·1, 95% confidence interval (CI) 1·4–12·2] and salad (RR 2·1, 95% CI 1·1–4) were associated with illness. Both items contained pre-washed, ready-to-eat cucumber slices. Microsporidia may be an under-reported cause of gastrointestinal outbreaks; we recommend that microsporidia be explored as potential causative agents in food- and waterborne outbreaks, especially when no other organisms are identified.

Foodborne outbreaks from contaminated fresh produce have been increasingly recognized in many parts of the world. This reflects a convergence of increasing consumption of fresh produce, changes in production and distribution, and a growing awareness of the problem on the part of public health officials. The complex biology of pathogen contamination and survival on plant materials is beginning to be explained. Adhesion of pathogens to surfaces and internalization of pathogens limits the usefulness of conventional processing and chemical sanitizing methods in preventing transmission from contaminated produce. Better methods of preventing contamination on the farm, or during packing or processing, or use of a terminal control such as irradiation could reduce the burden of disease transmission from fresh produce. Outbreak investigations represent important opportunities to evaluate contamination at the farm level and along the farm-to-fork continuum. More complete and timely environmental assessments of these events and more research into the biology and ecology of pathogen-produce interactions are needed to identify better prevention strategies.

We investigated an outbreak of Shigella sonnei infections in Denmark and Australia associated with imported baby corn from one packing shed in Thailand. We reviewed nationwide surveillance and undertook case finding, food trace-back and microbiological investigation of human, food and environmental samples. A recall of baby corn and sugar snaps was based on descriptive epidemiological evidence. In Denmark, we undertook a retrospective cohort study in one workplace. In total, 215 cases were laboratory-confirmed in Denmark, and 12 in Australia. In a multivariable analysis, baby corn was the only independent risk factor. Antibiotic resistance and PFGE outbreak profiles in Denmark and Australia were indistinguishable, linking the outbreaks. Although we did not detect S. sonnei in baby corn, we isolated high levels of other enteric pathogens. We identified a packing shed in Thailand that supplied baby corn to Denmark and Australia, and uncovered unhygienic practices in the supply chain. This outbreak highlights the importance of international communication in linking outbreaks and pinpointing the source.

In December 2006 an outbreak of Campylobacter infection occurred in Forth Valley, Scotland, affecting 48 people over a 3-week period. All cases dined at restaurant A. We conducted a cohort study in a party of 30 who ate lunch at restaurant A on 21 December to identify the vehicle of infection. Of 29 respondents, the attack rate in those who ate chicken liver pâté was 86% (6/7) compared to 0% (0/22) for those who did not. Between 1 December and 1.30 p.m. on 21 December the restaurant had used a different method of cooking the pâté. No cases reported dining at the restaurant after this time. The outbreak's duration suggested a continuous source. This is the first continuous source outbreak of Campylobacter documented in Scotland. Chicken liver pâté was the most likely vehicle of infection. This outbreak illustrates the hazards associated with undercooking Campylobacter-contaminated food.