Limiting worker exposure to highly pathogenic avian influenza a (H5N1): a repeat survey at a rendering plant processing infected poultry carcasses in the UK

<p>Abstract</p> <p>Background</p> <p>Current occupational and public health guidance does not distinguish between rendering plant workers and cullers/poultry workers in terms of infection risk in their respective roles during highly pathogenic avian influenza poultry outbreaks. We describe an operational approach to human health risk assessment decision making at a large rendering plant processing poultry carcasses stemming from two separate highly pathogenic avian influenza A (H5N1) outbreaks in England during 2007.</p> <p>Methods</p> <p>During the first incident a uniform approach assigned equal exposure risk to all rendering workers in or near the production line. A task based exposure assessment approach was adopted during the second incident based on a hierarchy of occupational activities and potential for infection exposure. Workers assessed as being at risk of infection were offered personal protective equipment; pre-exposure antiviral prophylaxis; seasonal influenza immunisation; hygiene advice; and health monitoring. A repeat survey design was employed to compare the two risk assessment approaches, with allocation of antiviral prophylaxis as the main outcome variable.</p> <p>Results</p> <p>Task based exposure assessment during the second incident reduced the number of workers assessed at risk of infection from 72 to 55 (24% reduction) when compared to the first incident. No cases of influenza like illness were reported in workers during both incidents.</p> <p>Conclusions</p> <p>Task based exposure assessment informs a proportionate public health response in rendering plant workers during highly pathogenic avian influenza H5N1 outbreaks, and reduces reliance on extensive antiviral prophylaxis.</p

Clusters of Legionnaires' disease in period hotels with complex water systems: lessons learnt in the West Midlands, UK

BackgroundIn 2017 there were two distinct clusters of local travel-associated Legionnaires' disease associated with period hotels built in the 17th and 18th centuries in the West Midlands, UK. Both hotels had undergone frequent structural modifications. Five cases occurred 3 months to 2 years apart. The aim of this report is to share the learning from the investigations and challenges faced in achieving control of Legionella pneumophila in the water systems of dated buildings.MethodsEpidemiological information was obtained through structured cases interviews and through linked cases by the national surveillance scheme database. Hotel water system maintenance records were reviewed, and samples were taken at numerous timepoints and different locations, with an initial focus on facilities and rooms used by the cases. Sputum and environmental samples were tested in the reference laboratory and sequence-based typing was undertaken.FindingsUnsatisfactory levels of L pneumophila serogroup 1 were detected from hot and cold water outlets in both hotels. At one of the hotels L pneumophila serogroup 1, sequence type ST62 subtypes in clinical and environmental samples were indistinguishable. Both hotels were closed for business for months to undertake extensive remediation work. This closure was temporarily effective in achieving adequate control of legionella but 6 months later routine monitoring detected unsatisfactory levels. Achieving sustained legionella control in dated water systems and verifying safe endpoints for hotel re-opening has proven challenging for the regulatory bodies.InterpretationSustaining legionella control in the dated water systems of period buildings was demanding, and public confidence in the effectiveness of control measures was compromised. There were four key challenges: defining a cluster and the timely confirmation of when an outbreak has developed; using the cluster and outbreak definitions to inform the risk assessments and review of control measures in the environmental investigations; communicating the risk to the public and the media through clear messages; and seeking assurance on safety of water management systems in defining the endpoint for a cluster or outbreak investigation

Outbreak of food poisoning linked to leeks in cheese sauce: an unusual source.

Between 11-13 December 2018, local public health authorities in the West Midlands, England were alerted to 34 reports of diarrhoea with abdominal cramps. Symptom onset was ~10 h after diners ate Christmas meals at a restaurant between 7-9 December 2018. A retrospective case-control study, environmental and microbiological investigations were undertaken to determine the source and control the outbreak. An analytical study was undertaken with odds ratios (OR) and 95% confidence intervals (CI). Forty persons were recruited to the analytical study (28/40 cases). Multivariable analysis found that leeks in cheese sauce was the only item associated with illness (aOR 51.1; 95% CI 4.13-2492.1). Environmental investigations identified significant lapses in food safety, including lapses in temperature control during cooking and hot holding, likely cross-contamination between raw and cooked foods and the reuse of leftover cheese sauce for the next day's service. No food samples were taken during the exposure period. Two faecal samples were positive for Clostridium perfringens with one confirming the enterotoxigenic gene. Cheese sauce is an unusual vehicle for the organism and the first time this has been reported in England