Source attributed case-control study of campylobacteriosis in New Zealand.

BACKGROUND: Following an initial reduction in human campylobacteriosis in New Zealand after the implementation of poultry food chain-focused interventions during 2006-2008, further decline has been relatively small. We report a year-long study of notified campylobacteriosis cases, incorporating a case control study combined with a source attribution study. The purpose was to generate up-to-date evidence on the relative contributions of different sources of campylobacteriosis in New Zealand. METHODS: The study approach included: • A case-control study of notified cases (aged six months or more) sampled in a major urban centre (Auckland, every second case) and a mixed urban/rural area (Manawatu/Whanganui, every case), between 12 March 2018 and 11 March 2019. • Source attribution of human campylobacteriosis cases sampled from these two regions over the study period by modelling of multilocus sequence typing data of Campylobacter jejuni and C. coli isolates from faecal samples of notified human cases and relevant sources (poultry, cattle, sheep). RESULTS: Most cases (84%) were infected with strains attributed to a poultry source, while 14% were attributed to a cattle source. Approximately 90% of urban campylobacteriosis cases were attributed to poultry sources, compared to almost 75% of rural cases. Poultry consumption per se was not identified as a significant risk factor. However specific risk factors related to poultry meat preparation and consumption did result in statistically significantly elevated odds ratios. CONCLUSIONS: The overall findings combining source attribution and analysis of specific risk factors indicate that poultry meat remains a dominant pathway for exposure and infection.

Incubation period for campylobacteriosis and its importance in the estimation of incidence related to travel.

Differentiation between travel-related and domestic cases of infectious disease is important in managing risk. Incubation periods of cases from several outbreaks of campylobacteriosis in Canada, Europe, and the United States with defined exposure time of less than 24 hours were collated to provide information on the incubation period distribution. This distribution was consistent across the varied outbreaks considered, with 84% (702/832) of cases having an incubation period of four days or less and 1% having an incubation period of eight days or more. The incubation period distribution was incorporated into a model for the number of travel-related cases presenting with symptom onset at given dates after return to their country of residence. Using New Zealand notification data between 2006 and 2010 for cases who had undertaken foreign travel within 10 days prior to symptom onset, we found that 29.6% (67/227 cases; 95% confidence interval (CI): 28.3­30.8%) of these cases were likely to have been domestic cases. When cases with symptom onset prior to arrival were included, the probable domestic cases represented 11.8% (67/571; 95% CI: 11.2­12.3%). Consideration of incubation time distributions and consistent collection of travel start/end dates with symptom onset dates would assist attribution of cases to foreign travel.

Acute gastrointestinal illness in New Zealand: a community study.

We report the results of the New Zealand Acute Gastrointestinal Illness (AGI) Community Study, a representative cross-sectional community telephone survey of 3655 participants conducted over a 12-month period. Respondents were asked questions about vomiting and diarrhoea in the previous 4 weeks. At least one episode of diarrhoea and/or vomiting was reported by 8·6% of respondents, an incidence of 1·11 episodes/person per year. Prevalence was highest in children aged <5 years and lowest in those aged >64 years. The mean duration of illness was 2·5 days and most common symptoms were diarrhoea (82·5%), stomach cramps (75·7%), nausea (56·9%) and vomiting (49·0%). Extrapolation of the adjusted estimates indicates there are about 4·66 million episodes of AGI per year in New Zealand, nearly 1 million visits to the general medical practitioner, in excess of 300,000 courses of antibiotics being dispensed and more than 4·5 million days of paid work lost due to AGI. This represents a significant burden of disease.

The disease pyramid for acute gastrointestinal illness in New Zealand.

The disease pyramid of under-ascertainment for surveillance of acute gastrointestinal illness (AGI) in New Zealand has been estimated using 2005-2007 data on notifiable diseases, a community telephone survey, and a survey of diagnostic laboratories. For each notified case of AGI there were an estimated 222 cases in the community, about 49 of which visited a general practitioner. Faecal samples were requested from about 15 of these cases, and 13 samples were provided. Of the faecal samples, pathogens were detected in about three cases. These ratios are similar to those reported in other developed countries, and provide baseline measurements of the AGI burden in the New Zealand community.

Survey of domestic food handling practices in New Zealand.

The purpose of this survey was to obtain information on the domestic meat and poultry handling practices of New Zealanders in order to support the development of quantitative risk models, as well as providing data to underpin food safety campaigns to consumers. A sample of 1000 New Zealand residents, over 18 years of age, were randomly selected from the electoral roll and asked to participate in a national postal food safety study during 2005. Three hundred and twenty six respondents completed and returned questionnaires containing usable answers, and most of these respondents 'always' prepared the main meal within the household. The majority of meat (84.6%) and poultry (62.9%) purchased by New Zealanders was fresh (rather than frozen), and most consumers (94.4%) claimed that the time taken from food selection to reaching their home was 1 h or less. The majority (approximately 64%) of fresh meat and poultry was frozen in the home and the most favoured method of thawing was at room temperature for up to 12 h. The most common time period for storing cooked or raw meat and poultry in domestic refrigerators was up to 2 days. Most survey respondents preferred their meat and poultry to be cooked either medium or well done. The most popular cooking method for chicken was roasting or baking, while most respondents preferred to pan-fry steak/beef cuts, minced beef or sausages/hamburgers. The potential for undercooking was greatest with pan-fried steak with 19.8% of respondents preferring to consume this meat raw or rare. In answer to questions relating to food handling hygiene practices, 52.2% of respondents selected a hand washing sequence that would help prevent cross contamination. However, it was estimated that 41% and 28% of respondents would use knives and kitchen surfaces respectively in a manner that could allow cross contamination. The data in this survey are self-reported and, particularly for the hygiene questions, respondents may report an answer that they perceive as being correct rather than reflecting their actual behaviour. Nevertheless, the data on food processing, transport, storage and cooking preferences represent useful inputs into the assessment of food safety along the meat and poultry food chains.

NOESY on neurotoxins: NMR and conformational assignments of picrotoxins.

Nuclear Overhauser effect spectroscopy (NOESY) gave full assignments of the 1H-NMR spectra of the picrotoxane neurotoxins tutin, hyenanchin, picrotoxinin and picrotin, as well as the solution conformations of these compounds, consistent with molecular modelling. Fully assigned 13C-NMR data are reported.

Rapid detection of Listeria monocytogenes in ham samples using immunomagnetic separation followed by polymerase chain reaction.

AIMS: To develop a 24-h system for the detection of Listeria monocytogenes in ham. METHODS AND RESULTS: An immunomagnetic separation (IMS) of bacteria directly from ham followed by extraction of DNA and detection using a new multiplex polymerase chain reaction (PCR) was used. The PCR method used one primer pair targeted at the listeriolysin O gene of L. monocytogenes and the other pair for a region of the 23S rRNA genes of Listeria, giving products of 706 and 239 bp, respectively. The combined IMS/PCR was calculated to be capable of detecting as few as 1.1 L. monocytogenes cells g-1 in a 25-g ham sample. CONCLUSION: The process produced acceptable results, but the IMS step is the main barrier to further improvement of sensitivity. The DNA isolation was the most time-consuming step in the process. SIGNIFICANCE AND IMPACT OF THE STUDY: A 24-h test for the presence of L. monocytogenes will be useful to the food industry and significantly assist in the timely investigation of outbreaks.

Estimated number of cases of foodborne infectious disease in New Zealand.

AIMS: To estimate the annual number of cases of infectious intestinal disease caused by foodborne pathogens in New Zealand and estimate the impact of these diseases in terms of days lost to illness. METHODS: Incidence of foodborne diseases were derived from data from infectious disease surveillance and hospital sources, and estimates of unreported illnesses using published population based studies. RESULTS: The estimated number of cases of foodborne infectious disease is approximately 119 000 per year, including 19 000 general practitioner visits, 400 hospital admissions, 22 cases of long term illness and two deaths. It is estimated that the number of cases of potentially foodborne infectious disease is approximately 199 000. Total number of cases of all infectious intestinal disease could be as high as 823 000. Days of lost production and leisure time activities lost to foodborne infectious disease are estimated as approximately 497 000. CONCLUSION: Foodborne infectious diseases represent a major public health burden in terms of the number of cases and days lost to illness.

Economic cost to New Zealand of foodborne infectious disease.

AIMS: To estimate the annual economic cost to New Zealand of foodborne infectious disease. METHODS: Annual incidence rates were combined with unit cost data to derive estimates of the annual economic cost to society of each foodborne infectious disease. Market prices and wages were used as proxies for the unit costs of resource utilisations. A decision analytic model was developed to estimate the costs of each disease and to undertake sensitivity analysis. RESULTS: There are an estimated 119 320 episodes of foodborne infectious disease per year in New Zealand (3241 per 100 000 population). The total cost of these cases was $55.1 million ($462 per case) made up of direct medical costs of $2.1 million, direct non-medical costs of $0.2 million, indirect cost of lost productivity of $48.1 million, and intangible cost of loss of life of $4.7 million. Campylobacteriosis generated most of the costs. Lost productivity was the major cost component for all diseases. The total cost of potentially foodborne infectious disease was estimated to be $88.8 million. Broad estimates of additional costs due to cases of infectious intestinal diseases caused by non-foodborne pathogens or for which no pathogen is identified could raise the cost to $215.7 million. CONCLUSION: The findings imply that resources of $55 million could be devoted to prevention of foodborne infectious disease. Efforts should focus on lowering the incidence of campylobacteriosis as this disease accounts for most of foodborne illness costs.

Notch signaling: cell fate control and signal integration in development.

Notch signaling defines an evolutionarily ancient cell interaction mechanism, which plays a fundamental role in metazoan development. Signals exchanged between neighboring cells through the Notch receptor can amplify and consolidate molecular differences, which eventually dictate cell fates. Thus, Notch signals control how cells respond to intrinsic or extrinsic developmental cues that are necessary to unfold specific developmental programs. Notch activity affects the implementation of differentiation, proliferation, and apoptotic programs, providing a general developmental tool to influence organ formation and morphogenesis.

Comparison of mouse bioassay and sodium channel cytotoxicity assay for detecting paralytic shellfish poisoning toxins in shellfish extracts.

A neuroblastoma cell culture assay was used to analyze shellfish extracts for presence of paralytic shellfish poisoning toxins (saxitoxins). Results were compared with mouse bioassays performed as part of a screening program for shellfish toxins in New Zealand. Twenty-nine samples gave negative results in both assays. Fifty-seven samples gave positive results in at least one assay. The correlation between the assays for saxitoxin equivalent levels in shellfish was 0.867. In spiking studies on shellfish extracts, the neuroblastoma assay showed a good response to added saxitoxin. Although these results support use of the neuroblastoma assay as a screening procedure for shellfish toxicity, results close to regulatory limits should be confirmed by mouse bioassay.

Cell cycle- and terminal differentiation-associated regulation of the mouse mRNA encoding a conserved mitotic protein kinase.

We determined the nucleotide sequence of a mouse and a human cDNA, which we designate STPK13, that encodes an apparent protein kinase related to that encoded by the Drosophila melanogaster polo gene and the Saccharomyces cerevisiae CDC5 gene. The polo and CDC5 gene products are required for normal mitosis. The STPK13 mRNA is regulated during terminal erythrodifferentiation and during the cell cycle. Within the precommitment period of murine erythroleukemia cell terminal differentiation, most of the poly(A) tail is lost from the STPK13 mRNA, but the body of the mRNA remains unchanged in abundance; this poly(A) loss does not occur in mutant erythroleukemia cells that fail to commit to terminal differentiation. During the cell cycle, the abundance of the body of the STPK13 mRNA fluctuates. The mRNA is present in growing but not in nongrowing cells. It reaches a maximum abundance during G2/M phase, is absent or present at only low levels during G1 phase, and begins to reaccumulate at approximately the middle of S phase. The cell cycle-associated accumulation and loss of the STPK13 mRNA could cause a similar fluctuation in abundance of its encoded protein kinase, thereby providing a maximum amount during M phase, when the kinase is thought to function, and little or none at other times of the cell cycle. Posttranscriptional regulation must be responsible for the cell cycle-associated fluctuations because transcription rates are relatively constant during different times of the cell cycle when there are large differences in mRNA abundance.