Jo Middleton

The management of scabies outbreaks in residential care facilities for the elderly in England: a review of current health protection guidelines.

Commonly thought of as a disease of poverty and overcrowding in resource-poor settings globally, scabies is also an important public health issue in residential care facilities for the elderly (RCFE) in high-income countries such as the UK. We compared and contrasted current local Health Protection Team (HPT) guidelines for the management of scabies outbreaks in RCFE throughout England. We performed content analysis on 20 guidelines, and used this to create a quantitative report of their variation in key dimensions. Although the guidelines were generally consistent on issues such as the treatment protocols for individual patients, there was substantial variation in their recommendations regarding the prophylactic treatment of contacts, infection control measures and the roles and responsibilities of individual stakeholders. Most guidelines did not adequately address the logistical challenges associated with mass treatment in this setting. We conclude that the heterogeneous nature of the guidelines reviewed is an argument in favour of national guidelines being produced.

Scabies outbreaks in ten care homes for elderly people: a prospective study of clinical features, epidemiology, and treatment outcomes

Summary Background Scabies outbreaks in residential and nursing care homes for elderly people are common, subject to diagnostic delay, and hard to control. We studied clinical features, epidemiology, and outcomes of outbreaks in the UK between 2014 and 2015. Methods We did a prospective observational study in residential care homes for elderly people in southeast England that reported scabies outbreaks to Public Health England health protection teams. An outbreak was defined as two or more cases of scabies (in either residents or staff) at a single care home. All patients who provided informed consent were included; patients with dementia were included if a personal or nominated consultee (ie, a family member or nominated staff member) endorsed participation. Dermatology-trained physicians examined residents at initial clinical visits, which were followed by two mass treatments with topical scabicide as per local health protection team guidance. Follow-up clinical visits were held 6 weeks after initial visits. Scabies was diagnosed through pre-defined case definitions as definite, probable, or possible with dermatoscopy and microscopy as appropriate. Findings 230 residents were examined in ten outbreaks between Jan 23, 2014, and April 13, 2015. Median age was 86·9 years (IQR 81·5–92·3), 174 (76%) were female, and 157 (68%) had dementia. 61 (27%) residents were diagnosed with definite, probable, or possible scabies, of whom three had crusted scabies. Physical signs differed substantially from classic presentations. 31 (51%) of the 61 people diagnosed with scabies were asymptomatic, and only 25 (41%) had burrows. Mites were visualised with dermatoscopy in seven (11%) patients, and further confirmed by microscopy in three (5%). 35 (57%) cases had signs of scabies only on areas of the body that would normally be covered. Dementia was the only risk factor for a scabies diagnosis that we identified (odds ratio 2·37 [95% CI 1·38–4·07]). At clinical follow-up, 50 people who were initially diagnosed with scabies were examined. No new cases of scabies were detected, but infestation persisted in ten people. Interpretation Clinical presentation of scabies in elderly residents of care homes differs from classic descriptions familiar to clinicians. This difference probably contributes to delayed recognition and suboptimal management in this vulnerable group. Dermatoscopy and microscopy were of little value. Health-care workers should be aware of the different presentation of scabies in elderly people, and should do thorough examinations, particularly in people with dementia. Funding Public Health England and British Skin Foundation.

Scabies in residential care homes: Modelling, inference and interventions for well-connected population sub-units

In the context of an ageing population, understanding the transmission of infectious diseases such as scabies through well-connected sub-units of the population, such as residential care homes, is particularly important for the design of efficient interventions to mitigate against the effects of those diseases. Here, we present a modelling methodology based on the efficient solution of a large-scale system of linear differential equations that allows statistical calibration of individual-based random models to real data on scabies in residential care homes. In particular, we review and benchmark different numerical methods for the integration of the differential equation system, and then select the most appropriate of these methods to perform inference using Markov chain Monte Carlo. We test the goodness-of-fit of this model using posterior predictive intervals and propagate forward the resulting parameter uncertainty in a Bayesian framework to consider the economic cost of delayed interventions against scabies, quantifying the benefits of prompt action in the event of detection. We also revisit the previous methodology used to assess the safety of treatments in small population sub-units—in this context ivermectin—and demonstrate that even a very slight relaxation of the implicit assumption of homogeneous death rates significantly increases the plausibility of the hypothesis that ivermectin does not cause excess mortality based upon the data of Barkwell and Shields.

Can interventions that aim to decrease Lyme disease hazard at non-domestic sites be effective without negatively affecting ecosystem health? A systematic review protocol

BackgroundLyme disease (LD) is the most commonly reported, broadly distributed vector-borne disease of the northern temperate zone. It is transmitted by ticks and, if untreated, can cause skin, cardiac, nervous system and musculoskeletal disease. The distribution and incidence of LD is increasing across much of North America and Western Europe. Interventions to decrease exposure to LD hazard by encouraging behavioural change have low acceptance in high risk groups, and a safe, effective human LD vaccine is not presently available. As a result, habitat level interventions to decrease LD hazard itself (i.e. levels of infected ticks) have been proposed. However, some interventions may potentially negatively affect ecosystem health, and consequentially be neither desirable, nor politically feasible. This systematic review will catalogue interventions that aim to reduce LD hazard at non-domestic sites, and examine the evidence supporting those which are unlikely to negatively affect ecosystem health.MethodsThe review will be carried out in two steps. First, a screening and cataloguing stage will be conducted to identify and characterise interventions to decrease LD hazard at non-domestic sites. Secondly, the subset of interventions identified during cataloguing as unlikely to negatively affect ecosystem health will be investigated. In the screening and cataloguing step literature will be collected through database searching using pre-chosen search strings, hand-searching key journals and reviewing the websites of public health bodies. Further references will be identified by contacting stakeholders and researchers. Article screening and assessment of the likely effects of interventions on ecosystem health will be carried out independently by two reviewers. A third reviewer will be consulted if disagreements arise. The cataloguing step results will be presented in tables. Study quality will then be assessed independently by two reviewers, using adapted versions of established tools developed in healthcare research. These results will be presented in a narrative synthesis alongside tables. Though a full meta-analysis is not expected to be possible, if sub-groups of studies are sufficiently similar to compare, a partial meta-analysis will be carried out.

Can outbreak research be achieved in a population with impaired capacity? Findings from a study of a scabies outbreak in residential care

Abstract Background Disease outbreaks in residential care where dementia is prevalent are an important public health concern and challenging to study. To explore the feasibility of outbreak research in a population lacking mental capacity we studied scabies outbreaks in residential care homes for elderly people. Methods Between Jan 23, 2014, and April 23, 2015, participants were recruited from ten residential care homes in South East England reporting scabies outbreaks to their local health protection unit. Preliminary visits were organised in advance of clinical visits to assess mental capacity and, when appropriate, seek consent from residents to be recruited and clinically examined. When residents did not have the capacity to consent, advice was sought from a personal consultee (usually next of kin) via telephone and followed up with written confirmation. When a personal consultee could not be contacted or did not exist, advice was sought from a nominated consultee (institution staff). Researchers were trained to assess mental capacity and did so at each visit because capacity often fluctuates in this population. During two clinical visits, residents were fully examined and skin conditions recorded and photographed. When scabies was diagnosed, skin scrapes and blood samples were taken for analysis and stored for future research. The study was approved by Camberwell St Giles NRES Committee (12/LO/0001). Findings Of 295 residents approached, 144 (49%) were assessed as having capacity to consent and 122 (41%) gave written consent; consultee advice was sought for 151 (51%). All 24 nominated consultees and 117 (92%) of 127 personal consultees advised that they thought the person without capacity would wish to take part. Consent or positive advice was obtained from 264 (89%) of 295 residents for clinical examinations and skin scrapes and from 187 (71%) of 264 residents for photography of skin conditions. Separate consent for storage of tissue and blood samples was introduced partway through and consent or positive advice was obtained for 100 (66%) of 151 residents. 231 (88%) of 264 residents were examined: 155 (67%) had dementia, of whom 54 (35%) were able to give written consent, and differences in the perceived and assessed capacity between care home staff and researchers were noted. 191 (83%) of the 231 participants were examined at both clinical visits. Reasons why 40 residents were not examined at the 6 week follow-up visit included: deceased (13, 33%), respite or re-enablement (10, 25%), unwell or distressed (7, 18%), admission to hospital (5, 13%), unable to schedule appointment (3, 8%), and refused (2, 5%). 12 (6%) of 191 participants experienced fluctuating mental capacity. Clinical visits took place within a median 5 days (IQR 3–8) of notification of the outbreak to the study team. Interpretation Public health research during outbreaks in residential care is complex but achievable. It requires substantial resource and training to deliver rapid and repeated assessment of mental capacity and obtain timely consultee advice in line with the Mental Capacity Act 2005. Funding Public Health England and the British Skin Foundation.