Retrospective assessment of rapid outbreak investigation for gastrointestinal diseases using only cases and background exposure data.

For outbreaks of gastrointestinal disease, rapid identification of the source is crucial to enable public health intervention and prevent further cases. Outbreak investigation comprises analyses of exposure information from cases and, if required, undertaking analytical epidemiological studies. Hypothesis generation has been reliant on empirical knowledge of exposures historically associated with a given pathogen. Epidemiology studies are resource-intensive and prone to bias, one of the reasons being the difficulties in recruiting appropriate controls. For this paper, the information from cases was compared against pre-defined background exposure information. As exemplars, three past outbreaks were used, one of common and two of rare exposures. Information from historical case trawling questionnaires was used to define background exposure having removed any exposures implicated with the outbreak. The case-background approach showed good sensitivity and specificity, identifying correctly all outbreak-related exposures. One additional exposure related to a retailer was identified and four food items where all cases had been exposed. In conclusion, the case-background method, a development of the case-case design, can be used to assist with hypothesis generation or when a case-control study may not be possible to carry out.

Use of gender distribution in routine surveillance data to detect potential transmission of gastrointestinal infections among men who have sex with men in England.

Detecting gastrointestinal (GI) infection transmission among men who have sex with men (MSM) in England is complicated by a lack of routine sexual behavioural data. We investigated whether gender distributions might generate signals for increased transmission of GI pathogens among MSM. We examined the percentage male of laboratory-confirmed patient-episodes for patients with no known travel history for 10 GI infections of public health interest in England between 2003 and 2013, stratified by age and region. An adult male excess was observed for Shigella spp. (annual maximum 71% male); most pronounced for those aged 25-49 years and living in London, Brighton and Manchester. An adult male excess was observed every year for Entamoeba histolytica (range 59.8-76.1% male), Giardia (53.1-57.6%) and Campylobacter (52.1-53.5%) and for a minority of years for hepatitis A (max. 69.8%) and typhoidal salmonella (max. 65.7%). This approach generated a signal for excess male episodes for six GI pathogens, including a characterised outbreak of Shigella among MSM. Stratified analyses by geography and age group were consistent with MSM transmission for Shigella. Optimisation and routine application of this technique by public health authorities elsewhere might help identify potential GI infection outbreaks due to sexual transmission among MSM, for further investigation.

Online market research panel members as controls in case-control studies to investigate gastrointestinal disease outbreaks: early experiences and lessons learnt from the UK.

Established methods of recruiting population controls for case-control studies to investigate gastrointestinal disease outbreaks can be time consuming, resulting in delays in identifying the source or vehicle of infection. After an initial evaluation of using online market research panel members as controls in a case-control study to investigate a Salmonella outbreak in 2013, this method was applied in four further studies in the UK between 2014 and 2016. We used data from all five studies and interviews with members of each outbreak control team and market research panel provider to review operational issues, evaluate risk of bias in this approach and consider methods to reduce confounding and bias. The investigators of each outbreak reported likely time and cost savings from using market research controls. There were systematic differences between case and control groups in some studies but no evidence that conclusions on the likely source or vehicle of infection were incorrect. Potential selection biases introduced by using this sampling frame and the low response rate are unclear. Methods that might reduce confounding and some bias should be balanced with concerns for overmatching. Further evaluation of this approach using comparisons with traditional methods and population-based exposure survey data is recommended.

The effect of pharmacists on ward rounds measured by the STOPP/START tool in a specialized geriatric unit.

WHAT IS KNOWN AND OBJECTIVE: The STOPP/START tool has been validated to assess elderly patients for potentially inappropriate prescribing. This study aimed to assess the effect of inclusion of a pharmacist on a physician-led ward round on potentially inappropriate prescribing in hospitalized elderly patients. METHODS: This was an observational study of prescribing for patients using the STOPP/START tool at three points during hospital stay; admission to hospital, on transfer to the specialized geriatric unit and on discharge from hospital. Data were collected over 4 months pre- and post-introduction of a pharmacist to a physician-led ward round. Demographic and clinical data, including total number of medications and STOPP/START criteria met, were collected. The mean number of STOPP/START criteria at each time-point was compared for pre- and post-introduction of a pharmacist using a Mann-Whitney U-test. The mean number of criteria for each time-point within each group was compared using a paired Student's t-test. RESULTS AND DISCUSSION: The demographic characteristics of the participants in the pre- and post-intervention groups were similar. The post-intervention group had numerically less STOPP/START criteria, mean 1·18 (1·37) compared to the pre-intervention group 1·50 (1·41), P = 0·07 at discharge. The pre-intervention group had no significant change in the criteria from admission 1·78 (1·57) to geriatric unit transfer 1·72 (1·54) (P = 0·37); however, there was a significant decrease from geriatric unit transfer 1·72 (1·54) to discharge 1·50 (1·41) (P = 0·02). The post-intervention group had a significant decrease from hospital admission 2·30 (1·91) to geriatric unit transfer 1·59 (1·60) (P < 0·01) and again to discharge 1·18 (1·37) (P < 0·01). WHAT IS NEW AND CONCLUSION: Pharmacist participation on the ward round in a specialized geriatric unit resulted in a numerical improvement in prescribing quality as measured by the STOPP/START tool.

Selection of population controls for a Salmonella case-control study in the UK using a market research panel and web-survey provides time and resource savings.

Timely recruitment of population controls in infectious disease outbreak investigations is challenging. We evaluated the timeliness and cost of using a market research panel as a sampling frame for recruiting controls in a case-control study during an outbreak of Salmonella Mikawasima in the UK in 2013. We deployed a web-survey by email to targeted members of a market research panel (panel controls) in parallel to the outbreak control team interviewing randomly selected public health staff by telephone and completing paper-based questionnaires (staff controls). Recruitment and completion of exposure history web-surveys for panel controls (n = 123) took 14 h compared to 15 days for staff controls (n = 82). The average staff-time cost per questionnaire for staff controls was £13·13 compared to an invoiced cost of £3·60 per panel control. Differences in the distribution of some exposures existed between these control groups but case-control studies using each group found that illness was associated with consumption of chicken outside of the home and chicken from local butchers. Recruiting market research panel controls offers time and resource savings. More rapid investigations would enable more prompt implementation of control measures. We recommend that this method of recruiting controls is considered in future investigations and assessed further to better understand strengths and limitations.

Investigation of an outbreak of vomiting in nurseries in South East England, May 2012.

On 30 May 2012, Surrey and Sussex Health Protection Unit was called by five nurseries reporting children and staff with sudden onset vomiting approximately an hour after finishing their lunch that day. Over the following 24 h 50 further nurseries supplied by the same company reported cases of vomiting (182 children, 18 staff affected). Epidemiological investigations were undertaken in order to identify the cause of the outbreak and prevent further cases. Investigations demonstrated a nursery-level attack rate of 55 out of 87 nurseries (63·2%, 95% confidence interval 52·2-73·3). Microbiological tests confirmed the presence of Bacillus cereus in food and environmental samples from the catering company and one nursery. This was considered microbiologically and epidemiologically consistent with toxin from this bacterium causing the outbreak. Laboratory investigations showed that the conditions used by the caterer for soaking of pearl haricot beans (known as navy bean in the USA) used in one of the foods supplied to the nurseries prior to cooking, was likely to have provided sufficient growth and toxin production of B. cereus to cause illness. This large outbreak demonstrates the need for careful temperature control in food preparation.

Changes in job aspirations during physician training in Australia.

BACKGROUND: There is uncertainty regarding the effects of physician training on planned practice features of Australian physician trainees, for example plans for urban or rural, full-time or part-time and academic/research or purely clinical practice. These plans may differ between male and female trainees and between generalists and sub-specialists. AIM: To examine the changes in anticipated practice patterns over the course of advanced physician training. METHODS: Longitudinal study of doctors in Australia who passed the Part I clinical examination of the Royal Australasian College of Physicians in 1991, 1992 and 1993, followed annually up until 1995. Changes in future practice plans regarding full- or part-time work, rural or urban practice and pure clinical work or a mixture with research were examined among generalist and specialist trainees and among men and women. Statistical analysis included the calculation of chi square for trend statistics and intraclass correlation coefficients. RESULTS: At least one follow-up questionnaire was received form 80% of the 334 original respondents. The majority had been able to obtain their training job of choice. By the time of last follow-up, around 80% planned to practise in a capital city, indicating a shift during training from those who initially stated no preference. There was also a shift towards combining research with clinical practice and among women wishing to practise part-time only. Generalists were more likely to wish to practise outside a capital city than specialists. CONCLUSIONS: The training programme should be revised so that careers in rural and provincial centres are encouraged and so that it is sensitive to the needs for physicians to develop research capacity. Training and career opportunities should allow all candidates (particularly women) wishing part-time employment to achieve their full career potential.