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

Escalating Threat of Drug-Resistant Human Scabies: Current Insights and Future Directions

Background: Scabies is a prevalent dermatological condition with significant public health implications. The recent rise in drug-resistant scabies presents new challenges for effective disease management and control. Methods: A comprehensive literature review was conducted using PubMed, Cochrane Library, and Web of Science. Studies published from 2000 to August 2024 were considered, focusing on those reporting drug-resistant scabies and advancements in treatment approaches. Results: Clinical studies, in vitro investigations, and case reports show significant resistance of human scabies to permethrin. Main resistance mechanisms involve genetic mutations in the mites' voltage-gated sodium channels (VGSCs) and enhanced activity or expression of the detoxifying enzyme glutathione S-transferase (GST). Resistance to ivermectin and benzyle benzoate, although suggested by some authors, seems less obvious. The clinical evidence of widespread ivermectin resistance in human scabies infestations is lacking, despite indications of increased tolerance in laboratory settings and anecdotal reports of resistance in patients with crusted scabies. Benzyl benzoate resistance in scabies mites remains unconfirmed. Conclusions: Permethrin-resistant scabies is an escalating threat requiring new management strategies and updated guidelines. Infection control measures, alternative treatments, and ongoing research into new therapeutics are crucial to mitigate the impact of drug-resistant scabies.

Scabies outbreak management in refugee/migrant camps in Europe 2014-2017: a retrospective qualitative interview study of healthcare staff experiences and perspectives

OBJECTIVES

Provide insights into the experiences and perspectives of healthcare staff who treated scabies or managed outbreaks in formal and informal refugee/migrant camps in Europe 2014-2017.

DESIGN

Retrospective qualitative study using semistructured telephone interviews and framework analysis. Recruitment was done primarily through online networks of healthcare staff involved in medical care in refugee/migrant settings.

SETTING

Formal and informal refugee/migrant camps in Europe 2014-2017.

PARTICIPANTS

Twelve participants (four doctors, four nurses, three allied health workers, one medical student) who had worked in camps (six in informal camps, nine in formal ones) across 15 locations within seven European countries (Greece, Serbia, Macedonia, Turkey, France, the Netherlands, Belgium).

RESULTS

Participants reported that in camps they had worked, scabies diagnosis was primarily clinical (without dermatoscopy), and treatment and outbreak management varied highly. Seven stated scabicides were provided, while five reported that only symptomatic management was offered. They described camps as difficult places to work, with poor living standards for residents. Key perceived barriers to scabies control were (1) lack of water, sanitation and hygiene, specifically: absent/limited showers (difficult to wash off topical scabicides), and inability to wash clothes and bedding (may have increased transmission/reinfestation); (2) social factors: language, stigma, treatment non-compliance and mobility (interfering with contact tracing and follow-up treatments); (3) healthcare factors: scabicide shortages and diversity, lack of examination privacy and staff inexperience; (4) organisational factors: overcrowding, ineffective interorganisational coordination, and lack of support and maltreatment by state authorities (eg, not providing basic facilities, obstruction of self-care by camp residents and non-governmental organisation (NGO) aid).

CONCLUSIONS

We recommend development of accessible scabies guidelines for camps, use of consensus diagnostic criteria and oral ivermectin mass treatments. In addition, as much of the work described was by small, volunteer-staffed NGOs, we in the wider healthcare community should reflect how to better support such initiatives and those they serve.

Increased Scabies Incidence at the Beginning of the 21st Century: What Do Reports from Europe and the World Show?

Reports from various countries have described increasing numbers of scabies cases, especially in the past two decades. The epidemiological data for various world regions showed prevalence estimates ranging from 0.2% to 71%, with the highest prevalence in the Pacific region and Latin America. Therefore, geographically, scabies occurs more commonly in the developing world, tropical climates, and in areas with a lack of access to water. According to results from specific regions of the world, the greatest burdens from scabies were recorded for East Asia, Southeast Asia, Oceania, tropical Latin America, and South Asia. Among countries with the highest rates, the top 10 were Indonesia, China, Timor-Leste, Vanuatu, Fiji, Cambodia, Laos, Myanmar, Vietnam, and the Seychelles. From Europe, available data shows an increasing trend in scabies infestation, particularly evident among populations with associated contributing factors, such as those who travel frequently, refugees, asylum seekers, those who regularly lack drinking water and appropriate hygiene and are of a younger age, etc. This increase in observed cases in the last 10-20 years has been evidenced by research conducted in Germany, France, Norway, and Croatia, among other countries. In addition, increased scabies transmission was also recorded during the COVID-19 pandemic and may have been the result of increased sexual intercourse during that time. Despite all the available treatment options, scabies commonly goes unrecognized and is therefore not treated accordingly. This trend calls for a prompt and synergistic reaction from all healthcare professionals, governmental institutions, and non-governmental organizations, especially in settings where population migration is common and where living standards are low. Furthermore, the proper education of whole populations and accessible healthcare are cornerstones of outbreak prevention. Accurate national data and proper disease reporting should be a goal for every country worldwide when developing strategic plans for preventing and controlling the community spread of scabies.

Scabies: Epidemiology, Diagnosis, and Treatment

BACKGROUND

Scabies is a skin infestation whose incidence is apparently rising.

METHODS

This review is based on pertinent articles retrieved by a selective search of PubMed on diagnosis and treatment strategies.

RESULTS

Thread-like papules (burrows), new, intense pruritus, and dermatitis guide the suspected diagnosis which is confirmed by the microscopic or dermatoscopic demonstration of scabies mites. The first line therapy is topical application of permethrin, in accordance with the current recommendations for its use. Other treatment options include systemic ivermectin and topical crotamiton or benzyl benzoate. A combination of permethrin and ivermectin is used to treat otherwise intractable cases and is generally indicated for the treatment of crusted scabies. Known causes of treatment failure include improper application of the external agents, failure of repeated treatment with ivermectin, incomplete decontamination of furnishings and clothes, failure to simultaneously treat contact persons, absence of written documents explaining treatment modalities, and the patient's belonging to a risk group. Even though there has not yet been any direct proof of resistance of scabies mites to permethrin, there is a rising number of welldocumented cases of poor response to this agent. Moxidectin is a new substance now undergoing clinical testing.

CONCLUSION

Treatment of scabies according to the guidelines and the additional recommendations reported here should result in effective curing, even in cases that are thought to be intractable.

Prevalence of scabies in long-term care hospitals in South Korea

BACKGROUND

Scabies is a common contagious skin disease. With the economic growth in South Korea, the incidence of scabies has decreased. However, with the recent advancements in medical facilities, mainly the establishment of long-term care hospitals (LTCHs), scabies is now considered an emerging public health problem.

METHODOLOGY/PRINCIPAL FINDINGS

To examine the prevalence and management of scabies in LTCHs in South Korea, we contacted all 1,336 LTCHs registered at the Health Insurance Review and Assessment Service in South Korea in 2018. A total of 110 LTCHs completed a questionnaire, and we analyzed their responses. In the last 5 years, 71.8% (79/110) of LTCHs had a high incidence of scabies (suspected/confirmed cases). Usually, patients aged older than 80 years (45.5%) were diagnosed with the disease, with more women being affected than men. Only 30.0% of the patients were transferred to scabies-restricted rooms, and very few LTCHs (7.0%) had special departments for scabies. Fifty-five (61.1%) of 90 LTCHs reported contact between scabies patients and nurses, nurse aides, caregivers, and other employees (hereinafter, referred to as primary exposure), with 29 (32.2%) LTCHs reporting infections due to primary exposure. The most common challenges in managing scabies were patient isolation (47.8%), diagnosis (31.1%), management of individuals exposed to an individual with scabies (17.8%), lack of staff for managing the patients (16.7%), and treatment (11.1%).

CONCLUSIONS

The incidence rate of scabies in LTCHs in South Korea has increased. Regular and enhanced staff training is needed, considering that most hospitals rarely focused on the handling of equipment and furniture used by scabies patients and on educating their healthcare staff. These findings can be used to develop various strategies to reduce the prevalence of scabies.

The public health importance of scabies in community domiciliary care settings: an exploratory cross-sectional survey of Health Protection Teams in England

Scabies is a contagious skin infection commonly occurring in institutions such as care homes. However, a large proportion of vulnerable people in England receive domiciliary care in the community and their experience of scabies has not been described. We undertook a pragmatic cross-sectional survey of Health Protection Teams (HPTs) in England to determine the burden of scabies related to domiciliary care. Fifteen cases or outbreaks were notified to HPTs between January 2013 and December 2017. Although a relatively uncommon event for individual HPTs, they were complex to manage and required the co-ordination of multiple stakeholders. Diagnosis was often delayed and required several clinical consultations. A lack of guidance led to difficulties establishing stakeholder roles and responsibilities and sources of funding for treatment. The stigmatisation of scabies sometimes affected the quality of care provided to patients, such as use of excessive personal protective equipment. Our study demonstrates that scabies is an issue of public health importance for domiciliary care service providers and users, and research is required to better understand the impacts of the disease and to develop evidence-based guidance. More generally, there is a need for simpler treatment regimens and methods of diagnosing scabies.

Do we know how scabies outbreaks in residential and nursing care homes for the elderly should be managed? A systematic review of interventions using a novel approach to assess evidence quality

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.

The public health control of scabies: priorities for research and action

Scabies is a parasitic disease of the skin that disproportionately affects disadvantaged populations. The disease causes considerable morbidity and leads to severe bacterial infection and immune-mediated disease. Scientific advances from the past 5 years suggest that scabies is amenable to population-level control, particularly through mass drug administration. In recognition of these issues, WHO added scabies to the list of neglected tropical diseases in 2017. To develop a global control programme, key operational research questions must now be addressed. Standardised approaches to diagnosis and methods for mapping are required to further understand the burden of disease. The safety of treatments for young children, including with ivermectin and moxidectin, should be investigated. Studies are needed to inform optimum implementation of mass treatment, including the threshold for intervention, target, dosing, and frequency. Frameworks for surveillance, monitoring, and evaluation of control strategies are also necessary.

Implementation and evaluation of an algorithm for the management of scabies outbreaks

Background

Infestations with scabies mites are a global burden affecting individuals of all ages, classes and ethnicities. As poor sanitation and overcrowding favor the transmission of this highly contagious disease, epidemic outbreaks are frequently observed among displaced persons and asylum seekers. Due to the growing influx of refugees during the last years, public health authorities in host countries are frequently confronted with the challenge to treat individuals with diagnosed or suspected scabies promptly and effectively to avoid further spreading of the infestation.

This study aimed to establish a straightforward and efficient algorithm for rapid screening and treatment of large numbers of patients with confirmed or suspected scabies infestations.

Methods

Forty-eight individuals (58% males, mean age 22.4 yrs.) from Syria with suspected scabies infestation were allocated to 3 colour-coded groups: (1) no signs or symptoms of infestation, (2) itch only, and (3) itch and typical skin lesions. Patients were treated with a single (group 1) or two doses of oral ivermectin at an interval of 7 days (group 2), or with a combination of 2 doses of ivermectin plus 2 applications of permethrin ointment at an interval of 7 days (group 3). Follow-ups were performed 4 weeks after initial treatments.

Results

All individuals with signs and/or symptoms of infestation had improved skin lesion; in 10/11 (90.9%) lesion had completely resolved. All individuals with initial itch only (n = 32) reported improvement of its intensity or complete resolution. None of the patients of group 1 developed itch or skin lesions. The algorithm was reapplied in 4 individuals (8.3%) after 4 weeks and the outbreak was completely controlled after 8 weeks. Colour-coding ensured fast flow of information between health-care providers at the interfaces of the algorithm.

Conclusions

Our algorithm proved to be both highly efficient for treatment of large numbers of patients with suspected or diagnosed scabies infestation as well as for prevention of spreading of the disease. Hence, this algorithm is well suited for the management of scabies mass outbreaks.

Infected with Scabies Again? Focus in Management in Long-Term Care Facilities

Scabies is a significant public health condition in long-term care facilities, plaguing even developed countries. Although treatments are available, eradication and control of scabies cases still remain a challenge due to delays in diagnosis and difficulties in maintaining preventive and surveillance measures. Prompt treatment of patients and their contacts that are affected, along with concomitant education of health staff and family members, are paramount. Environmental disinfestation is also a concern.

Control Strategies for Scabies

Scabies is a neglected tropical disease of the skin, causing severe itching and stigmatizing skin lesions. Further, scabies leads to impetigo, severe bacterial infections, and post-infectious complications. Around 200 million people are affected, particularly among disadvantaged populations living in crowded conditions in tropical areas. After almost 50 years, research into scabies control has shown great promise, particularly in highly-endemic island settings, but these findings have not been widely adopted. Newer approaches, utilizing ivermectin-based mass drug administration, appear feasible and highly effective. Inclusion of scabies in the WHO portfolio of neglected tropical diseases in 2017 may facilitate renewed opportunities and momentum toward global control. However, further operational research is needed to develop evidence-based strategies for control in a range of settings, and monitor their impact. Several enabling factors are required for successful implementation, including availability of affordable drug supply. Integration with existing health programs may provide a cost-effective approach to control.

Management of a family outbreak of scabies with high risk of spread to other community and hospital facilities

BACKGROUND

In developed countries, scabies is observed sporadically or as institutional outbreaks in hospitals and other health facilities. In the family context, outbreaks generally involve a limited number of cases.

METHODS

A local health authority in Emilia-Romagna (Northern Italy) carried out an epidemiologic investigation on a family outbreak of scabies that included an unusually high number of cases. Its possible connection with a nosocomial case in a long-term care facility (LTCF) and outbreak management are discussed.

RESULTS

Among the household members, 8 confirmed cases occurred (attack rate, 87.5%). Another case was reported in a patient of an LTCF where one of the family cases worked as a sociosanitary operator. In total, 244 contacts were placed under surveillance. The control strategy focused on a mass information campaign addressed to all contacts and the training of health care personnel. In addition, specific prophylaxis (permethrin 5%) was performed in 108 high-risk contacts and LTCF patients and staff.

CONCLUSIONS

The control measures were successful in preventing the spread of the outbreak. However, misdiagnosis and the tendency of people to hide the symptoms caused the late recognition and underestimation of the cases, contributing to delayed control measures and increasing the economic and human resources required for outbreak management.

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

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.