Introduction: Scabies is a skin infestation caused by the mite Sarcoptes Scabiei var. hominis. WHO included the disease among the Neglected Tropical Diseases in the year 2017. Ethiopia bears a very high scabies burden and a series of scabies outbreaks have been recorded in the past few years. To respond to growing public health concern, the Ethiopian Federal Ministry of Health is looking for approaches to control the disease. In Ethiopia, Mass Drug Administration (MDA) with ivermectin has been taking place for the control of onchocerciasis since 2003 but its secondary effects on the transmission of scabies have not been evaluated.

Aim: The aim of this study was to evaluate the effect of MDA for onchocerciasis on the transmission of scabies.

Methods: A comparative cross-sectional study design with multi-stage sampling was used. Districts in Ethiopia, with varying time of onset of MDA were selected. Data were collected using a pretested structured interview questionnaire on the prevalence of scabies infestation, socioeconomic and socio-demographic variables, and health service utilization. The recently developed Consensus Criteria were used by the trained field data collectors (clinical nurses) and an experienced dermatologist to screen and identify clinical cases of scabies during a house-to-house survey. In one district, pre- and post- MDA data are being collected to measure the effectiveness of MDA.

Results: To date, data from one district have been analyzed. This comprises household and individual level data from 402 households and 1400 individuals. The prevalence of scabies was estimated to be 15% (210 cases/1400 individuals). Half (105) of the cases have been re-evaluated by the dermatologist.

Conclusion:Our preliminary findings suggest that prevalence of scabies in the district in which ivermectin MDA has been carried out since 2015 is still high. The agreement between clinical nurses and the dermatologist on scabies case identification was good. By finding out the impact of varying time of onset of ivermectin MDA on scabies, we anticipate formulating an improved control strategy for scabies, thereby reducing the burden of the disease.

Currently no national guidelines exist for the management of scabies outbreaks in residential or nursing care homes for the elderly in the United Kingdom. In this setting, diagnosis and treatment of scabies outbreaks is often delayed and optimal drug treatment, environmental control measures and even outcome measures are unclear. We undertook a systematic review to establish the efficacy of outbreak management interventions and determine evidence-based recommendations. Four electronic databases were searched for relevant studies, which were assessed using a quality assessment tool drawing on STROBE guidelines to describe the quality of observational data. Nineteen outbreak reports were identified, describing both drug treatment and environmental management measures. The quality of data was poor; none reported all outcome measures and only four described symptom relief measures. We were unable to make definitive evidence-based recommendations. We draw on the results to propose a framework for data collection in future observational studies of scabies outbreaks. While high-quality randomised controlled trials are needed to determine optimal drug treatment, evidence on environmental measures will need augmentation through other literature studies. The quality assessment tool designed is a useful resource for reporting of outcome measures including patient-reported measures in future outbreaks.
Nineteen outbreak reports were identified, describing both drug treatment and environmental management measures. The quality of data was poor; none reported all outcome measures and only four described symptom relief measures. We were unable to make definitive evidence-based recommendations. We draw on the results to propose a framework for data collection in future observational studies of scabies outbreaks.

While high quality randomized controlled trials are needed to determine optimal drug treatment, evidence on environmental measures will need augmentation through other literatures. The quality assessment tool designed is a useful resource for reporting of outcome measures including patient-reported measures in future outbreaks.

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.

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 [1].

Background
New Guinea has the third largest tropical rainforest on Earth. However, one quarter of the forests of Papua New Guinea (PNG, New Guinea’s eastern half) have been cleared or degraded, nearly half through commercial logging.Sustainable development requires supporting good health (Sustainable Development Goal [SDG] 3) and protecting life on land (SDG 15). To remote communities in PNG with low levels of health provision, these goals can seem in conflict. Logging companies’ offer of roads and income can partly extinguish the remoteness that bars access to health services, making desire for health a driver for forest destruction and erosion of health related ecosystem services. Conservation success thus requires synergies be developed with delivery of other SDGs, particularly those pertaining to health. We aim to provide a model of integrated health and conservation in PNGs rainforests.

Methods
We are mapping and piloting biological, anthropological, and medical methods to address SDGs on health and biodiversity, focusing first on scabies and fungal diseases. At Wanang, team members have a long term collaboration with nine clans with unmet health needs who collectively chose to preserve their 10,000 hectare forest whilst surrounding communities allowed logging. Similar collaborations are being developed along an altitudinal transect on Mt.Wilheim (4,509m). Stage 1 of Surfaces will (i) systematically map evidence on integrated conservation and health programmes, (ii) conduct clinical examinations and rapid anthropological assessments to understand medical needs, and survey skin disease, and (iii) produce a case study of the Wanang agreement, based on interviews with participants. This will lay the foundation for a multi-year health intervention and interdisciplinary study.

Findings
We are in the projects’ early stages (so do not yet have findings), and would appreciate advice and suggestions of collaboration from others in the Planetary Health community.

Funding
Sussex Sustainability Research Programme, University of Sussex, UK.

Contributions
All authors have commented on multiple drafts and approved the final version of the abstract for publication.

Conflicts of interest
We declare we have no conflicts of interest.

Acknowledgments
We thank the projects partner communities; New Guinea Binatang Research Centre; and our advisory group.

Background

Scabies is a contagious parasitic skin condition often found in nursing and residential care homes for the elderly (NRC),[1] where dementia is common. Scabies can present differently in older people[2] and diagnostic delays can facilitate outbreaks which require distressing topical mass treatment.[3]

Methods

We conducted a qualitative study to explore how Primary Care Clinicians (PCCs) diagnose scabies in NRCs to identify areas where targeted training may improve outcomes. We undertook semi-structured interviews with PCCs from SE England who had treated patients in NRCs in the previous two years. These were recorded, transcribed and thematically analysed.

Results

14 General Practitioners (GPs) and 7 trainee GPs of varying age, gender and experience participated. PCCs reported approaching diagnosis through history and examination of symptomatic residents, often diagnosing scabies after treating for other dermatological conditions. All PCCs expected to see an intense pruritic rash, classic lesions, and burrows in the finger web spaces, and most would only examine other body regions if the patient complained of itching. Many PCCs reported a lack of confidence in diagnosing scabies and advocated more education about scabies in this setting.

Discussion

A recent prospective study of scabies outbreaks in NRCs found over half of those with scabies had never complained, and signs were mainly found at atypical locations. Dementia was significantly associated with NRC residents having scabies.[4] In contrast our study shows that PCCs’ approach to diagnosing scabies in NRCs is based on “classical” presentation of scabies which may leave signs on other parts of the body overlooked. The impact of dementia on symptoms and the patient’s ability to communicate were not always considered. We recommend training and learning resources to improve PCCs’ skills and confidence to diagnose scabies in NRCs.

References

1. Mounsey KE, Murray HC, King M, Oprescu F. Retrospective analysis of institutional scabies outbreaks from 1984 to 2013: lessons learned and moving forward. Epidemiol Infect 2016: 1-10.
2. Wilson MM, Philpott CD, Breer WA. Atypical presentation of scabies among nursing home residents. J Gerontol A Biol Sci Med Sci. 2001; 56(7): M424.
3. Hewitt KA, Nalabanda A, Cassell JA. Scabies outbreaks in residential care homes: factors associated with late recognition, burden and impact. A mixed methods study in England. Epidemiol Infect 2015; 143(7): 1542-51.
4. Walker S, Cassell J, Nalanbanda A, et al. A prospective study of scabies outbreaks in ten residential care facilities for the elderly [meeting abstract]. Brit J Dermatol 2016; 175(S2 Special Issue): 65.

Introduction
Scabies is a significant problem in UK elderly residential care facilities (RCF); outbreaks are common and difficult to control. Clinical presentations in the elderly are poorly understood. We studied scabies outbreaks in RCFs to investigate the clinical signs and risk factors in this population.

Methods
We visited RCFs with suspected scabies outbreaks. We examined residents, performed dermoscopy and skin scrapings, and classified their scabies diagnosis as definite (mite visualised)/probable (compatible symptoms, mite not visualised)/possible (non-specific rash + contact with case) or non-scabies. All residents were treated twice with a topical scabicide, and a second visit conducted.

Results
We examined 230 residents at 10 RCFs between 03/02/2014-11/02/2015. Their median age was 87 years, 76% were female, and 68% had dementia. 61 (27%) had scabies (13% definite); 41% with burrows, 51% had not reported symptoms. Dermoscopy identified the mite in 7 cases (11.5%), skin scrapings in 3. We diagnosed a median 6 cases/RCF. Dementia was strongly associated with scabies (OR=2.4, 95% CI 1.4-4.1). No new cases were identified at the second visit (median interval 44 days), 10 cases still had scabies (2 probable, 8 possible).

Discussion
Scabies diagnosis is difficult in this population; half of cases were asymptomatic, and dermoscopy and skin scrapings were of limited diagnostic value. Our study is the first to confirm that dementia is a risk factor for scabies in this group. Careful examination of elderly residents of RCFs with suspected scabies outbreaks is important, particularly those with dementia, as they may have no obvious clinical signs.

Introduction
Scabies is an important public health problem in residential care homes for the elderly. The management of scabies outbreaks generally requires the simultaneous mass treatment of all residents and staff, which is stressful, time consuming and a drain on resources. The Department of Health recommends that care home managers report scabies outbreaks to local Health Protection Teams (HPTs) to assist with practical and logistical advice.

Methods
We undertook a mixed methods review of current local HPT guidelines for the management of scabies outbreaks in care homes in England to create a quantitative report of their variation in key dimensions. Guidelines were defined as any documents and resources used to help formulate support and advice. All guidelines currently in use were eligible for inclusion regardless of date, length or nature.

Results
Twenty four HPTs were operational at the time of review (July 2015); twenty guidelines were reviewed as four HPTs had not produced guidelines, and instead relied upon expert advice from within local infection control teams (ICTs). Although the guidelines were generally consistent on issues such as 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.

Recommendations
There is a need for nationally produced guidance for the management of scabies outbreaks in care homes. Although local HPTs have attempted to fill this gap, guidelines are highly variable in their scope and content. National guidance would be the most comprehensive way of ensuring a thorough and cohesive response to outbreaks of this unpleasant and debilitating condition in the elderly population living in long-term care facilities.