Richard Meldrum

Host Association of Campylobacter Genotypes Transcends Geographic Variation

ABSTRACT Genetic attribution of bacterial genotypes has become a major tool in the investigation of the epidemiology of campylobacteriosis and has implicated retail chicken meat as the major source of human infection in several countries. To investigate the robustness of this approach to the provenance of the reference data sets used, a collection of 742 Campylobacter jejuni and 261 Campylobacter coli isolates obtained from United Kingdom-sourced chicken meat was established and typed by multilocus sequence typing. Comparative analyses of the data with those from other isolates sourced from a variety of host animals and countries were undertaken by genetic attribution, genealogical, and population genetic approaches. The genotypes from the United Kingdom data set were highly diverse, yet structured into sequence types, clonal complexes, and genealogical groups very similar to those seen in chicken isolates from the Netherlands, the United States, and Senegal, but more distinct from isolates obtained from ruminant, swine, and wild bird sources. Assignment analyses consistently grouped isolates from different host animal sources regardless of geographical source; these associations were more robust than geographic associations across isolates from three continents. We conclude that, notwithstanding the high diversity of these pathogens, there is a strong signal of association of multilocus genotypes with particular hosts, which is greater than the geographic signal. These findings are consistent with local and international transmission of host-associated lineages among food animal species and provide a foundation for further improvements in genetic attribution.

Widespread acquisition of antimicrobial resistance among Campylobacter isolates from UK retail poultry and evidence for clonal expansion of resistant lineages

BackgroundAntimicrobial resistance is increasing among clinical Campylobacter cases and is common among isolates from other sources, specifically retail poultry - a major source of human infection. In this study the antimicrobial susceptibility of isolates from a UK-wide survey of Campylobacter in retail poultry in 2001 and 2004–5 was investigated. The occurrence of phenotypes resistant to tetracycline, quinolones (ciprofloxacin and naladixic acid), erythromycin, chloramphenicol and aminoglycosides was quantified. This was compared with a phylogeny for these isolates based upon Multi Locus Sequence Typing (MLST) to investigate the pattern of antimicrobial resistance acquisition.ResultsAntimicrobial resistance was present in all lineage clusters, but statistical testing showed a non-random distribution. Erythromycin resistance was associated with Campylobacter coli. For all antimicrobials tested, resistant isolates were distributed among relatively distant lineages indicative of widespread acquisition. There was also evidence of clustering of resistance phenotypes within lineages; indicative of local expansion of resistant strains.ConclusionsThese results are consistent with the widespread acquisition of antimicrobial resistance among chicken associated Campylobacter isolates, either through mutation or horizontal gene transfer, and the expansion of these lineages as a proportion of the population. As Campylobacter are not known to multiply outside of the host and long-term carriage in humans is extremely infrequent in industrialized countries, the most likely location for the proliferation of resistant lineages is in farmed chickens.

Achieving Control of Occupational Exposures to Engineered Nanomaterials.

Occupational exposures resulting from Engineered Nanomaterials (ENMs) can pose a challenge for applying traditional risk assessment, control, or evaluation standards. This article discusses the limitations in traditional risk management approaches when it comes to ENM exposures, reviews current monitoring options, and suggests an interim management framework until research can meet the standard of evidence required by legislators. The proposed Nanomaterial Occupational Exposure Management Model (NOEM) offers a pragmatic approach that integrates resources from current academic research to provide a framework that can be applied by both industry and regulators. The NOEM Model focuses on addressing three concerns to exposure management: Risk Assessment, Exposure Control, and Exposure Monitoring. The resources supported for meeting these three components involve the integration of the Control Banding Nanotool and Nano Reference Values, both of which have been piloted and accepted through peer-reviewed processes and industry consultation.

Variation in the microbiological quality of commercially produced vacuum-packed cooked sliced meat between production and the end of shelf-life

A study of the microbiological quality of cooked, sliced vacuum-packed meat was undertaken. Three hundred and eighty-one samples were taken (127 sets of three samples) from 55 commercial premises that produced packets of sliced, cooked, vacuum-packed meat for retail sale. The set of three samples consisted of one from the unsliced, cooked meat, one from the sliced product immediately after slicing, and one sliced packet for end of shelf-life testing. Samples were examined for aerobic colony count (ACC), Enterobacteriaceae, Escherichia coli, Listeria, and Salmonella. When compared to current UK guidelines for the quality of ready to eat food, samples were found to be unsatisfactory for ACC, Enterobacteriaceae, and E. coli. Unsatisfactory rates increased at the end of shelf-life compared to the unsliced meat sample results. No samples were positive for Listeria monocytogenes or Salmonella. This data is important for producers setting the shelf-life of their products.

Explaining the food safety behaviours of food handlers using theories of behaviour change: a systematic review

ABSTRACT Theories of behaviour change can explain the factors affecting food handlers’ use of food safety practices. A systematic review was conducted on this topic to identify which theories have been applied in this area and to determine which theories are the most consistent predictors of food handlers’ behaviours. Standard systematic review procedures were followed: comprehensive search strategy; relevance screening of abstracts; article characterization; data extraction; risk-of-bias assessment; and descriptive analysis. Among 19 relevant studies, the most commonly investigated theories were the Theory of Planned Behaviour (n = 9 studies) and Health Belief Model (n = 5). All investigated theories were useful to explain food handlers’ behavioural intentions and behaviours related to food safety across different settings, and could serve as useful frameworks for future research and practice. However, there was wide variability in the predictive ability of the theories and their specific constructs, indicating theories should be adapted to the local context of application.

Avian influenza prevalence among hunter-harvested birds in a remote Canadian First Nation community.

INTRODUCTION Avian influenza virus (AIV) prevalence has been associated with wild game and other bird species. The contamination of these birds may pose a greater risk to those who regularly hunt and consumed infected species. Due to resident concerns communicated by local Band Council, hunter-harvested birds from a remote First Nation community in subArctic Ontario, Canada were assessed for AIV. Hunters, and especially those who live a subsistence lifestyle, are at higher risk of AIV exposure due to their increased contact with wild birds, which represent an important part of their diet. METHODS Cloacal swabs from 304 harvested game birds representing several species of wild birds commonly hunted and consumed in this First Nation community were analyzed for AIV using real-time reverse transcription polymerase chain reaction. Subtyping was performed using reverse transcription polymerase chain reaction. Sequences were assembled using Lasergene, and the sequences were compared to Genbank. RESULTS In total, 16 of the 304 cloacal swab samples were positive for AIV. Of the 16 positive samples, 12 were found in mallard ducks, 3 were found in snow geese (wavies), and 1 positive sample was found in partridge. The AIV samples were subtyped, when possible, and found to be positive for the low pathogenic avian influenza virus subtypes H3 and H4. No samples were positive for subtypes of human concern, namely H5 and H7. CONCLUSIONS This work represents the first AIV monitoring program results of hunter-harvested birds in a remote subsistence First Nation community. Community-level surveillance of AIV in remote subsistence hunting communities may help to identify future risks, while educating those who may have the highest exposure about proper handling of hunted birds. Ultimately, only low pathogenic strains of AIV were found, but monitoring should be continued and expanded to safeguard those with the highest exposure risk to AIV.

The cooling profile of hot-cooked mussels stored in domestic insulated coolers amongst food vendors in Prince Edward Island, Canada

It is common during outdoor events on Prince Edward Island, Canada for vendors to store hot-cooked mussels in domestic coolers. Provincial legislation states that hot product should be maintained at a minimum of 60 °C. A study was conducted to ascertain how long mussels could be stored before the temperature decreased to less than 60 °C. Hot, cooked mussels were placed into coolers and the temperature measured every 10 min for 4 h. It was found that when the cooler was unopened, the mean temperature dropped to less than 60 °C in 56 min. For coolers opened every 10 min, the mean temperature decreased to less than 60 °C in 38 min. For coolers opened every 10 min with mussels removed, the mean temperature decreased to less than 60 °C in 52 min. It was concluded that mussels should not be stored for more than 30 min and temperature should be regularly monitored.

Bird harvesting practices and knowledge, risk perceptions, and attitudes regarding avian influenza among Canadian First Nations subsistence hunters: implications for influenza pandemic plans

BackgroundThere is concern of avian influenza virus (AIV) infections in humans. Subsistence hunters may be a potential risk group for AIV infections as they frequently come into close contact with wild birds and the aquatic habitats of birds while harvesting. This study aimed to examine if knowledge and risk perception of avian influenza influenced the use of protective measures and attitudes about hunting influenza-infected birds among subsistence hunters.MethodsUsing a community-based participatory research approach, a cross-sectional survey was conducted with current subsistence hunters (n = 106) residing in a remote and isolated First Nations community in northern Ontario, Canada from November 10–25, 2013. Simple descriptive statistics, cross-tabulations, and analysis of variance (ANOVA) were used to examine the distributions and relationships between variables. Written responses were deductively analyzed.ResultsANOVA showed that males hunted significantly more birds per year than did females (F1,96 = 12.1; p = 0.001) and that those who hunted significantly more days per year did not perceive a risk of AIV infection (F1,94 = 4.4; p = 0.040). Hunters engaged in bird harvesting practices that could expose them to AIVs, namely by cleaning, plucking, and gutting birds and having direct contact with water. It was reported that 18 (17.0%) hunters wore gloves and 2 (1.9%) hunters wore goggles while processing birds. The majority of hunters washed their hands (n = 105; 99.1%) and sanitized their equipment (n = 69; 65.1%) after processing birds. More than half of the participants reported being aware of avian influenza, while almost one third perceived a risk of AIV infection while harvesting birds. Participants aware of avian influenza were more likely to perceive a risk of AIV infection while harvesting birds. Our results suggest that knowledge positively influenced the use of a recommended protective measure. Regarding attitudes, the frequency of participants who would cease harvesting birds was highest if avian influenza was detected in regional birds (n = 55; 51.9%).ConclusionsOur study indicated a need for more education about avian influenza and precautionary behaviours that are culturally-appropriate. First Nations subsistence hunters should be considered an avian influenza risk group and have associated special considerations included in future influenza pandemic plans.

Are Campylobacter cases low risk for public health follow-up?

ObjectivesMost Campylobacter cases are treated as low risk enterics (LRE) and receive a mailed letter from Toronto Public Health (TPH) with a questionnaire to gather basic risk information. This study sought to identify reasons why Campylobacter cases who were sent this questionnaire did not respond to the letter and to determine whether any of these cases were working in a high-risk occupation.MethodsCases reported to TPH between June 11, 2012 and December 6, 2012 who had not returned the questionnaire within 30 days were telephoned. Participants were asked about awareness of the original letter, reasons for not responding, and whether they worked in a high-risk occupation.ResultsOf the 226 cases identified as not responding to the letter, 172 (76.1%) were reached, and 162 (71.7%) answered the survey questions. The most frequent reason chosen for not responding to the original letter was “forgot” (54.4%). The most common suggestion chosen for ways to encourage response to the original letter was “more information on importance of returning questionnaire” (19.1%). Of the 119 cases with a known occupation, 3 (2.4%) were employed in a sensitive occupation–these include a family physician, a food server, and a line cook. None worked while ill. When prompted with a list of reasons for not returning the questionnaire, the majority of respondents indicated that they “forgot” (54.4%); the next most frequent response was “recovered by illness no longer considered it relevant” (21.5%).ConclusionTo increase response rates in the future, a cover letter should more clearly explain why the response is being solicited by Public Health, even after recovery from the illness, and the form should be simplified for mail return. A very small number of clients originally not reached through the course of the routine LRE program were working in sensitive occupations. Since none reported working while ill, the likelihood of direct or indirect transmission of Campylobacter from these three individuals was low. Using a LRE system to monitor a widespread mostly low-morbidity gastroenteric illness can be an effective public health strategy.RésuméObjectifsLa plupart des cas de Campylobacter sont traités comme étant atteints d’un entéropathogène à risque modéré (ERM) et reçoivent par la poste une lettre du Service de santé publique de Toronto (SSPT) accompagnée d’un questionnaire pour recueillir des informations de base sur leurs risques. Nous avons cherché à connaître les raisons pour lesquelles certains cas auxquels le questionnaire a été envoyé n’ont pas répondu à la lettre et à déterminer si un ou plusieurs d’entre eux exerçaient une profession à risque élevé.MéthodeNous avons téléphoné aux cas déclarés au SSPT entre le 11 juin et le 6 décembre 2012 qui n’avaient pas retourné le questionnaire dans un délai de 30 jours. Nous avons demandé aux répondants s’ils se souvenaient de la lettre initiale, pourquoi ils n’y avaient pas répondu, et s’ils exerçaient une profession à risque élevé.RésultatsSur les 226 cas n’ayant pas répondu à la lettre, 172 (76,1%) ont été joints par téléphone, et 162 (71,7%) ont répondu aux questions du sondage. La raison la plus fréquemment citée pour n’avoir pas répondu à la lettre initiale était d’avoir ªoublié« (54,4%). Parmi les réponses suggérées pour encourager les gens à répondre à la lettre initiale à l’avenir, la plus communément choisie était de fournir ªplus d’information sur l’importance de retourner le questionnaire« (19,1%). Trois des 119 cas dont la profession était connue (2,4%) exerçaient une profession sensible: un médecin de famille, une serveuse et un cuisinier à la chaîne. Aucun d’entre eux n’avait travaillé pendant sa maladie. Lorsque nous leur avons proposé une liste de raisons possibles de n’avoir pas retourné le questionnaire, la majorité des répondants ont indiqué avoir ªoublié« (54,4%); l’autre réponse la plus souvent citée était d’avoir ªguéri de la maladie et ne plus juger la question pertinente« (21,5%).ConclusionPour augmenter le taux de réponse à l’avenir, une lettre d’accompagnement devrait clairement expliquer pourquoi le Service de santé publique cherche à obtenir ces réponses même après la guérison, et le formulaire devrait être plus simple à retourner par la poste. Un très petit nombre de cas non joints initialement par le programme d’ERM habituel exerçaient une profession sensible. Comme aucun n’a déclaré avoir travaillé pendant sa maladie, la probabilité de transmission directe ou indirecte de Campylobacter par ces trois sujets était faible. L’utilisation d’un système d’ERM pourrait être une stratégie de santé publique efficace pour surveiller une maladie gastroentérique étendue, généralement à faible morbidité.