Toward the global control of human scabies: introducing the International Alliance for the Control of Scabies

Scabies

Scabies is one of the most common and highest-burden skin diseases globally. Estimates suggest that >200 million people worldwide have scabies at any one time, with an annual prevalence of 455 million people, with children in impoverished and overcrowded settings being the most affected. Scabies infection is highly contagious and leads to considerable morbidity. Secondary bacterial infections are common and can cause severe health complications, including sepsis or necrotizing soft-tissue infection, renal damage and rheumatic heart disease. There is no vaccine or preventive treatment against scabies and, for the past 30 years, only few broad-spectrum antiparasitic drugs (mainly topical permethrin and oral ivermectin) have been widely available. Treatment failure is common because drugs have short half-lives and do not kill all developmental stages of the scabies parasite. At least two consecutive treatments are needed, which is difficult to achieve in resource-poor and itinerant populations. Another key issue is the lack of a practical, rapid, cheap and accurate diagnostic tool for the timely detection of scabies, which could prevent the cycle of exacerbation and disease persistence in communities. Scabies control will require a multifaceted approach, aided by improved diagnostics and surveillance, new treatments, and increased public awareness.

Ivermectin-Based Mass Drug Administration for Scabies in Northern India: A Single-Arm Community Intervention Trial

Background

Scabies and impetigo cause direct health effects and contribute to severe infectious and immune-mediated complications. Ivermectin-based mass drug administration can reduce scabies and impetigo prevalence in island settings with high prevalence, but the effectiveness in moderate-prevalence settings is not known.

Methods

We conducted a single-arm, before-after community intervention trial. Mass drug administration was offered to the entire population of 4 villages in Uttarakhand, India. The treatment consisted of 2 doses, given 7 days apart, of oral ivermectin (∼200 μg/kg), or topical 5% permethrin if ivermectin was contraindicated. The primary outcome was the prevalence of scabies at 12 months compared with baseline, as diagnosed using clinical assessment and the 2020 International Alliance for the Control of Scabies criteria. Secondary outcomes included the prevalence of impetigo at each time point. The trial was registered with the Australian and New Zealand Trials Registry (ACTRN12619001712190).

Results

In January 2020, 1211 participants were enrolled (100% of the estimated village population). Treatment coverage was high-1204 (99.4%) and 1177 (97.2%) received 1 and 2 doses, respectively. Scabies was diagnosed in 91 participants (7.5%) and impetigo in 15 (1.2%). In February 2021, 1190 (98.3% of baseline) participants re-enrolled, and of these 11 had scabies (0.9%; relative risk reduction, 87.7%; 95% CI, 77.1%-93.4%) and 5 had impetigo (0.4%; relative risk reduction, 66.1%; 95% CI, 7.0%-87.6%).

Conclusions

A single round of ivermectin-based mass drug administration substantially reduced the prevalence of scabies and impetigo in this setting with moderate scabies prevalence in northern India.

Tissue and circulating levels of IL-17A and FoxP3+ in patients with scabies: Correlation with clinical features

The scabies mite is known to induce a complicated immune response that involves both innate and long-term adaptive immunity. Many immune effectors and pathways are involved. Th17/Treg balance can influence the complex immune response to scabies. The immunological effectors including IL-17A, as a pro-inflammatory cytokine, and Treg cells, anti-inflammatory regulatory T cells, are essential for preserving cutaneous immunological homeostasis. So, evaluating these immune effectors may help in comprehending the pathophysiology of scabies and facilitate the development of new treatment approaches. This study examined the expression of IL-17A and FoxP3+ in the skin and serum of 50 scabies patients and 25 healthy controls. An assessment of their correlation with clinical features was performed. Regarding tissue response, scabietic patients exhibited a significant increase in IL-17A and FoxP3+ expression in their epidermis and dermis compared to controls (P<0.001), but the correlation between these factors was not significant in either area (P>0.05). Also, patients showed a significant increase in serum IL-17A levels compared to controls (P<0.001), with a significant association between serum IL-17A levels and lesion severity, but no significant correlation was observed between skin and serum responses (P>0.05). In conclusion, there was increased expression of both IL-17A and FoxP3+, with FoxP3+ being significantly more abundant than IL-17A in the skin of scabies patients. Skin FoxP3+ up-regulation has been linked to the severity of the condition.

Global prevalence and predictors of scabies among prisoners: systematic review and meta-analysis

INTRODUCTION

Scabies is a widespread issue in prisons due to overcrowded living conditions and limited healthcare resources. A recent study published in the Journal of Infection and Public Health discovered that the prevalence of scabies varies greatly among prisoners in different regions and facilities. This review aimed to determine the global prevalence and predictors of scabies among prisoners by conducting a systematic review and meta-analysis.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist to report the findings of our systematic review and meta-analysis. Relevant databases including PubMed, Cochrane Library, ScienceDirect, and other grey literature databases were used to search and retrieve articles. The study included both published and unpublished research written in English languages for studies reporting the prevalence of human scabies among prisoners. This review has been registered on PROSPERO. The heterogeneity of the data was evaluated using the I2 statistic. A meta-analysis was conducted using STATA 17 software, with a 95% confidence interval. The researchers also conducted publication bias and sensitivity analysis.

RESULTS

The review included 7 studies involving 1, 309,323 prisoners. All included studies involved cross-sectional study design. The prevalence of scabies among prisoners ranges from 0.72% in Italy to 41.01% in Cameroon. The global pooled prevalence of human scabies among prisoners was found to be 6.57% (95% CI; 2.16-19.94). According to subgroup analysis, the overall prevalence of scabies among African prisoners was 19.55% (95% CI; 9.44-40.45), while the prevalence among prisoners outside of Africa was 1.57% (95% CI; 0.77-3.19). The length of time spent in prison, sharing of clothing or beds, and hygiene practices were found to be factors that were significantly associated with the likelihood of prisoners developing human scabies.

CONCLUSION

The overall prevalence of human scabies is high among prisoners worldwide. Prisoners who spent more time in prison shared clothing or beds, and had poor hygiene practices were more likely to develop human scabies. Thus, efforts should be made by policymakers and program administrators to decrease the prevalence of scabies in prisons. The protocol for this systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews with registration number CRD42024516064.

Secondary Bacterial Infections in Patients with Atopic Dermatitis or Other Common Dermatoses

Secondary bacterial infections of common dermatoses such as atopic dermatitis, ectoparasitosis, and varicella zoster virus infections are frequent, with Staphylococcus aureus and Streptococcus pyogenes being the bacteria most involved. There are also Gram-negative infections secondary to common dermatoses such as foot dyshidrotic eczema and tinea pedis. Factors favoring secondary bacterial infections in atopic dermatitis, ectoparasitosis, and varicella zoster virus infections mainly include an epidermal barrier alteration as well as itch. Mite-bacteria interaction is also involved in scabies and some environmental factors can promote Gram-negative bacterial infections of the feet. Furthermore, the bacterial ecology of these superinfections may depend on the geographical origin of the patients, especially in ectoparasitosis. Bacterial superinfections can also have different clinical aspects depending on the underlying dermatoses. Subsequently, the choice of class, course, and duration of antibiotic treatment depends on the severity of the infection and the suspected bacteria, primarily targeting S. aureus. Prevention of these secondary bacterial infections depends first and foremost on the management of the underlying skin disorder. At the same time, educating the patient on maintaining good skin hygiene and reporting changes in the primary lesions is crucial. In the case of recurrent secondary infections, decolonization of S. aureus is deemed necessary, particularly in atopic dermatitis.

Risk factors for scabies in hospital: a systematic review

BACKGROUND

Annually, 175.4 million people are infected with scabies worldwide. Although parasitic infections are important nosocomial infections, they are unrecognized compared to bacterial, fungal, and viral infections. In particular, nonspecific cutaneous manifestations of scabies lead to delayed diagnosis and frequent nosocomial transmission. Hospital-based studies on the risk factors for scabies have yet to be systematically reviewed.

METHODS

The study followed the PRISMA guidelines and was prospectively registered in PROSPERO (CRD42023363278). Literature searches were conducted in three international (PubMed, Embase, and CINAHL) and four Korean (DBpia, KISS, RISS, and Science ON) databases. We included hospital-based studies with risk estimates calculated with 95% confidence intervals for risk factors for scabies infection. The quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tools. Two authors independently performed the screening and assessed the quality of the studies.

RESULTS

A total of 12 studies were included. Personal characteristics were categorized into demographic, economic, residential, and behavioral factors. The identified risk factors were low economic status and unhygienic behavioral practices. Being a patient in a long-term care facility or institution was an important factor. Frequent patient contact and lack of personal protective equipment were identified as risk factors. For clinical characteristics, factors were categorized as personal health and hospital environment. People who had contact with itchy others were at higher risk of developing scabies. Patients with higher severity and those with a large number of catheters are also at increased risk for scabies infection.

CONCLUSIONS

Factors contributing to scabies in hospitals range from personal to clinical. We emphasize the importance of performing a full skin examination when patients present with scabies symptoms and are transferred from settings such as nursing homes and assisted-living facilities, to reduce the transmission of scabies. In addition, patient education to prevent scabies and infection control systems for healthcare workers, such as wearing personal protective equipment, are needed.

Scabies: Immunopathogenesis and pathological changes

Scabies is an itchy skin disease caused by the burrowing mite Sarcoptes scabiei. During their lifespan, the female mites invade the stratum corneum and create tunnels, in which they reside, move, feed, deposit fecal pellets, and lay eggs. Recently, scabies was included in the World Health Organization roadmap for neglected tropical diseases 2021-2030. This review attempts to summarize our knowledge about the mite's biology and the disease pathogenesis, pathological changes, and complications. Generally, the host-parasite interaction in scabies is highly complex and involves different mechanisms, some of which are yet largely unknown. Elucidation of the nature of such interaction as well as the underlying mechanisms could allow a better understanding of the mite's biology and the development of novel diagnostic and therapeutic options for scabies control programs. Moreover, identification of the molecular basis of such interaction could unveil novel targets for acaricidal agents and vaccines.

Failure of scabies treatment: a systematic review and meta-analysis

BACKGROUND

Treatment failure is considered to be an important factor in relation to the increase in scabies incidence over the last decade. However, the regional and temporal differences, in addition to the predictors of therapy failure, are unclear.

OBJECTIVES

We aimed to conduct a systematic review of the prevalence of treatment failure in patients with scabies and investigation of associated factors.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Web of Science, Scopus, Global Health and the Cochrane Central Register of Controlled Trials from inception to August 2021 for randomized and quasi-randomized trials, in addition to observational studies that enrolled children or adults diagnosed with confirmed or clinical scabies treated with permethrin, ivermectin, crotamiton, benzyl benzoate, malathion, sulfur or lindane, and measured treatment failure or factors associated with treatment failure. We performed a random effects meta-analysis for all outcomes reported by at least two studies.

RESULTS

A total of 147 studies were eligible for inclusion in the systematic review. The overall prevalence of treatment failure was 15.2% [95% confidence interval (CI) 12.9-17.6; I2 = 95.3%, moderate-certainty evidence] with regional differences between World Health Organization regions (P = 0.003) being highest in the Western Pacific region (26.9%, 95% CI 14.5-41.2). Oral ivermectin (11.8%, 95% CI 8.4-15.4), topical ivermectin (9.3%, 95% CI 5.1-14.3) and permethrin (10.8%, 95% CI 7.5-14.5) had relatively lower failure prevalence compared with the overall prevalence. Failure prevalence was lower in patients treated with two doses of oral ivermectin (7.1%, 95% CI 3.1-12.3) compared with those treated with one dose (15.2%, 95% CI 10.8-20.2; P = 0.021). Overall and permethrin treatment failure prevalence in the included studies (1983-2021) increased by 0.27% and 0.58% per year, respectively. Only three studies conducted a multivariable risk factor analysis; no studies assessed resistance.

CONCLUSIONS

A second dose of ivermectin showed lower failure prevalence than single-dose ivermectin, which should be considered in all guidelines. The increase in treatment failure over time hints at decreasing mite susceptibility for several drugs, but reasons for failure are rarely assessed. Ideally, scabicide susceptibility testing should be implemented in future studies.

Scabies prevalence and its associated factors among prisoners in southern Ethiopia: An institution-based analytical cross-sectional study

BACKGROUND

Scabies is an ectoparasitic infestation that can easily spread during close human contact and in overcrowded areas such as prisons and public places where sanitation is a problem. Globally, as many as 300 million people are infested with scabies each year. Within Ethiopia, its burden in institutions like prisons is not well-studied. As a consequence, we sought to estimate the prevalence of scabies and also identify factors associated with it among prison inmates in southern Ethiopia.

METHODS

An institution-based analytical cross-sectional study design was employed. We used, a simple random sampling technique to select 422 prisoners. A pretested-structured questionnaire was used to collect the necessary information. EpiData version 4.2.0.0 and Statistical Packages for Social Science version 25 software were used for data entry and analysis respectively. Both descriptive and inferential statistics were computed. The model fitness was checked using the Hosmer-Lemeshow and omnibus tests. The association between the independent and outcome variables was presented in the form of a table showing the crude odds ratio and adjusted odds ratio (AOR) along with their 95% confidence interval (CI). The level of statistical significance was declared at P.value ≤ 0.05.

RESULTS

A total of 418 prisoners were interviewed, yielding a 99.1% response rate. The age of the participants ranged from 17 to 60 years. As many as 381 (91.1%) participants were male. The prevalence of scabies was found to be 8.9%. A history of sexual contact in the past two months, before imprisonment (AOR: 9.92 (95% CI 3.07, 32.02), P <0.001), a period of stay less than two months duration in the prison (AOR: 4.54 (95% CI 1.51, 13.54), P = 0.007), poor ventilation (AOR: 3.36 (95% CI 1.07, 10.58), P = 0.038), lack of hygiene soap (AOR: 5.53 (95% CI 1.45, 21.17), P = 0.012), and sharing clothes among each other (AOR: 3.81 (95% CI (1.09, 13.29), P = 0.036) were factors independently associated with a scabies infestation.

CONCLUSION

In this study, we found the prevalence of scabies was high among prison inmates in Wolaita Zone prison. Furthermore, scabies infestations were associated with a previous history of sexual contact, poorly ventilated rooms, lack of hygiene soaps for washing, and sharing clothes amongst the inmates. Prison administrations should be encouraged to improve sanitary and screening and isolation of prisoners during imprisonment.

Living in a large family and low daily water consumption substantially expose for human scabies in rural Ethiopia: a matched analysis

BACKGROUND

Scabies has been added to the neglected tropical diseases portfolio for large-scale disease control action since 2017 and is part of the WHO roadmap for NTDs 2021-2030, targeted at ending the neglect to achieve the sustainable development goals. Previous studies have not fitted matched analysis to identify predictors of scabies infestation in Ethiopia. Information is also scarce about predictors of scabies infestation in this area. Therefore, this study aimed to identify predictors of scabies infestation in rural Aneded District, northwest Ethiopia.

METHODS

A community-based matched case-control study involving 183 cases and 549 controls was undertaken from March 1 to May 31, 2021, in rural Aneded District. A two-stage sampling technique with a house-to-house census for the screening of scabies cases was employed. A structured questionnaire with questions on sociodemographics, behavior, water supply, sanitation, and hygiene, and delivery of scabies-specific interventions was used. Pretesting, training of data collectors and supervisors, and supervision were applied to keep the data quality. A multivariable conditional logistic regression model was fitted to identify predictors of scabies.

RESULTS

Unmarried individuals or those in separated families (adjusted matched odds ratio (AmOR = 2.71; 95% CI 1.30-5.65); those unable to read and write or in illiterate families (AmOR = 5.10; 95% CI 1.81-14.36); those in large families (AmOR = 6.67; 95% CI 2.83-15.73); households that had longer travel times for water collection (AmOR = 2.27; 95% CI 1.08-4.76); those that had low daily water consumption (AmOR = 6.69; 95% CI 2.91-15.37); households that disposed of solid wastes in open fields (AmOR = 5.60; 95% CI 2.53-12.40); and households that did not receive scabies-specific interventions (AmOR = 2.98; 95% CI 1.39-6.39) had increased odds of scabies.

CONCLUSIONS

Being unmarried, illiteracy, large family, long travel time for water collection, low daily water consumption, open dumping of solid wastes, and inaccessibility of scabies-specific interventions are predictors of scabies. This information is instrumental for redesigning improved scabies-specific interventions that consider educational status, marital status, family size, water collection time, daily water consumption, solid waste disposal, and equity and optimization in delivering existing interventions in rural Ethiopia.

Cloth sharing with a scabies case considerably explains human scabies among children in a low socioeconomic rural community of Ethiopia

BACKGROUND

In 2020, scabies were integrated into the WHO roadmap for neglected tropical diseases, aimed at ending the negligence to realize the SDGs. Ethiopia has also introduced scabies as a notifiable disease in drought-prone localities since 2015. Many of the previous studies employed study designs that might be subject to bias. Moreover, there is no scientific evidence about scabies in this area. Hence, this study aimed to determine the prevalence and associated factors of scabies among children aged below 15 years in rural Ethiopia.

METHODS

A community-based cross-sectional study was carried out among 942 children in rural kebeles of Lay Gayent District from March through May 15, 2021. A two-stage sampling technique was applied. Data on sociodemographics, housing, water supply and sanitation, children's personal hygiene, and caregivers' knowledge about scabies were collected by a structured questionnaire. Data quality was maintained through pretesting, training of data collectors and supervisors, and supervision. An adjusted binary logistic regression was modelled to identify factors associated with scabies. The Hosmer-Lemeshow goodness-of-fit test was run to check the model fitness.

RESULTS

The prevalence of scabies was 21.5% (95% CI 19.0-24.3). Maternal illiteracy (adjusted odds ratio (AOR) = 1.61; 95% CI 1.07-2.43); low household wealth (AOR = 2.04; 95% CI 1.25-3.33); unimproved water source (AOR = 1.58; 95% CI 1.05-2.40); not cleaning a house daily (AOR = 2.43; 95% CI 1.63-3.62); not trimming nails (AOR = 2.21; 95% CI 1.50-3.25); cloth sharing with a scabies case (AOR = 11.77; 95% CI 6.94-19.97); and low caregiver knowledge about scabies (AOR = 2.44; 95% CI 1.64-3.63) were factors associated with scabies.

CONCLUSIONS

Scabies remains a significant public health issue among children aged below 15 years in the district. Maternal illiteracy, low household wealth, unimproved water source, not cleaning a house daily, not trimming nails, cloth sharing with a scabies case, and low caregiver knowledge about scabies were factors associated with scabies. Community-wide interventions with prime emphasis on improving maternal education and caregivers' knowledge about scabies, upgrading household wealth, ensuring a safe water supply, providing healthy housing, and ensuring adequate personal hygiene are warranted.

Culturally supported health promotion to See, Treat, Prevent (SToP) skin infections in Aboriginal children living in the Kimberley region of Western Australia: a qualitative analysis

Background

While there are many skin infections, reducing the burden of scabies and impetigo for remote living Aboriginal people, particularly children remains challenging. Aboriginal children living in remote communities have experienced the highest reported rate of impetigo in the world and are 15 times more likely to be admitted to hospital with a skin infection compared to non-Aboriginal children. Untreated impetigo can develop into serious disease and may contribute to the development of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). As the largest organ protecting the body and visible to everyone, skin infections are often unsightly and very painful, therefore maintaining healthy skin and reducing the burden of skin infections is important for overall physical and cultural health and well-being. Biomedical treatments alone will not address these factors; therefore, a holistic, strengths-based approach that aligns with the Aboriginal world view of wellness is required to help reduce the prevalence of skin infections and their downstream consequences.

Methods

Culturally appropriate yarning sessions with community members were conducted between May 2019 and November 2020. Yarning sessions have been identified as a valid method for story sharing and collecting information. Semi-structured, face-to-face interviews and focus groups with school and clinic staff were conducted. When consent was provided, interviews were audio-recorded and saved as a digital recording in a de-identified format; for those yarning sessions not recorded, handwritten notes were scribed. Audio recordings and handwritten notes were uploaded into NVivo software prior to a thematic analysis being conducted.

Findings

Overall, there was a strong knowledge of recognition, treatment, and prevention of skin infections. However, this did not extend to the role skin infections play in causing ARF, RHD or kidney failure. Our study has confirmed three main findings: 1. The biomedical model of treatment of skin infections remained strong in interviews with staff living in the communities; 2. Community members have a reliance and belief in traditional remedies for skin infections; and 3. Ongoing education for skin infections using culturally appropriate health promotion resources.

Interpretation

While this study revealed ongoing challenges with service practices and protocols associated with treating and preventing skin infections in a remote setting, it also provides unique insights requiring further investigation. Bush medicines are not currently practiced in a clinic setting, however, using traditional medicines alongside biomedical treatment procedures facilitates cultural security for Aboriginal people. Further investigation, and advocacy to establish these into practice, procedures and protocols is warranted. Establishing protocols and practice procedures focused on improving collaborations between service providers and community members in remote communities is also recommended.

Funding

Funding was received from the National Health and Medical Research Council [NHMRC] (GNT1128950), Health Outcomes in the Tropical NORTH [HOT NORTH 113932] (Indigenous Capacity Building Grant), and WA Health Department and Healthway grants contributed to this research. A.C.B. receives a NHMRC investigator Award (GNT1175509). T.M. receives a PhD scholarship from the Australian Centre for Elimination of Neglected Tropical Diseases (ACE-NTD), an NHMRC centre of excellence (APP1153727).

Prevalence of scabies and associated factors among children aged 5-14 years in Meta Robi District, Ethiopia

BACKGROUND

Scabies is a public health problem that affects children and elders predominantly. Its burden is higher in resource-poor settings, and scabies has a significant impact on the long-term health of children. In Ethiopia, there is limited information about scabies in children. Therefore, the purpose of this study was to determine the prevalence of scabies and its associated factors among children aged 5-14 years in Meta Robi District, Ethiopia.

METHODS

A community-based cross-sectional study design using a multistage sampling technique was used to collect data from 457 participants by systematic random sampling. Scabies was diagnosed based on the clinical criteria set by the International Alliance for the Control of Scabies (IACS, 2020).

FINDINGS

The prevalence of scabies among children aged 5-14 years old was 19.26% (95%CI: 17.20-22.52). In addition, over half (54.6%) of identified cases of scabies were of moderate severity. Factors like families' low income (aOR = 2.72; 95%CI: 1.32-5.59), being a male child (aOR = 1.96, 95%CI: 1.61-4.01), using only water for hand washing (aOR = 2.01, 95%CI: 1.84-4.79), having a contact history of scabies/skin lesions (aOR = 4.15, 95%CI: 2.02-13.67), and sharing sleeping beds (aOR = 6.33, 95%CI: 2.09-19.13) were significantly associated with scabies.

CONCLUSION

The study highlights a high prevalence of scabies among children aged 5-14 years in the district. Provision of adequate health education for the community and children about the scabies and delivering mass drug administration to the district is suggested.

Comparative genomics of Sarcoptes scabiei provide new insights into adaptation to permanent parasitism and within-host species divergence

Sarcoptes scabiei is the causative agent of a highly contagious skin disease in humans and more than 100 mammals. Here, we reported the first chromosome-level reference genome of S. scabiei isolated from rabbits, with a contig N50 size of 5.92 Mb, a total assembled length of 57.30 Mb, ∼12.65% repetitive sequences and 9333 predicted protein-coding genes. The phylogenetic tree based on 1338 shared high-confidence single-copy orthologous genes estimated that the mammalian ectoparasite S. scabiei and the plant-feeding mite Tetranychus urticae separated ∼340 million years ago. Both neighbour-joining tree and principal component analysis of 20 mite populations isolated from four hosts (humans, pigs, dogs and rabbits) distributed in three countries (China, Australia and the USA) consistently supported genetic subdivisions according to host species rather than geographical location. The demographic history of S. scabiei reconstructed by multiple sequentially Markovian coalescent analysis suggested that S. scabiei isolated from rabbits, humans, dogs and pigs diverged ∼5000 years ago. Investigation of the homeobox (Hox) genes revealed that S. scabiei contains 8 of 10 canonical Hox genes that are present in the arthropod ancestor, and the absence of the Abd-A gene may correlate with the long gap between their front and back legs. Comparative genomics demonstrated that genes specific to scabies mites were mainly enriched in nutrition digestive systems, whereas genes in the families that involved detoxification (cytochrome P450, carboxyl/cholinesterases and the ATP-binding cassette transporter C group) were extremely contracted compared with that of other mites analysed in this study. Selective sweep analysis of mite populations from various pairs of two out of the four host species revealed that the strongest selective sweep signals were mainly enriched in cysteine-type peptidase activity and apoptosis. The results provided clues for the mechanisms of S. scabiei adaptation to a permanent parasitic lifestyle and knowledge that would enable further control of this highly contagious skin disease.

Crusted Scabies, a Neglected Tropical Disease: Case Series and Literature Review

Crusted scabies is a rare form of scabies that presents with more severe symptoms than those of classic scabies. It is characterized by large crusted lesions, extensive scales, thick hyperkeratosis, and contains a large number of highly contagious itch mites. Crusted scabies is more prevalent in immunocompromised, malnourished, and disabled individuals. This disease has been linked to a variety of health problems, including delayed diagnosis, infection risk, and high mortality, mainly from sepsis, and it has the potential to cause an outbreak due to its hyper-infestation, which makes it highly infectious. This article reports three cases of crusted scabies in North Sulawesi, Indonesia. Recent updates and a comprehensive review of the literature on the disease are also included, emphasizing the critical importance of early diagnosis and effective medical management of patients, which are necessary to prevent the complications and spread in communities.

Prevalence and determinants of scabies among school-age children in Central Armachiho district, Northwest, Ethiopia

Background

Scabies is a major global public health issue that might affect people from all socioeconomic levels. Globally, scabies affects more than 200 million people at any time. It remains one of the commonest skin diseases seen in developing countries including Ethiopia. Therefore, this study aimed to assess the prevalence and determinants of scabies among school-age children in Central Armachiho district, Northwest Ethiopia.

Methods

A community-based cross-sectional study was conducted from August to September 2020. A multi-stage sampling technique was used to select 850 study populations. Data was checked for its completeness, coded, and entered by using EPI-INFO version 7 and exported to the SPSS version 20 for analysis. A Binary logistic regression model was fitted to identify the determinants of scabies. Crude odds ratio (COR) and adjusted odds ratio (AOR) with 95% CI were used as measurements for the associations. P-values <0.005 were considered significant.

Result

Prevalence of scabies among the 850 participants studied was 10.82% (95% CI: 8.7–12.9). Contact history with confirmed scabies patient (AOR = 5.28,95% CI: 2.96–9.44), child not attending school (AOR = 3.08, 95% CI;1.45–6.54), rarely changing clothes (AOR = 2.43,95% CI: 1.27–4.62), sleeping on the floor (AOR = 4.11, 95% CI:1.95–8.67), bed sharing; (AOR = 3.38, 95% CI:2.86–6.15), rarely washing cloth: (AOR = 5.08,95% CI:2.75–9.36), living with internally displaced people; (AOR,95% CI: 3.47 (1.30–9.24) and using only water to wash hands; (AOR = 3.18,95% CI:1.74–5.80) had a statistically significant association with scabies infestation among school-age children.

Conclusion

The current study found nearly one out of ten school-age children had scabies. Not attended school, contact history with confirmed scabies patient, not washing cloth, infrequent changing clothes, bedding sharing, sleeping on the floor, living with internally displaced people, and only using water for handwashing practice were the independent predictors for the occurrence of scabies. Health education better to given to the parents or caregivers about the washing of clothing, changing clothes at least once per week, and avoid physical contact with known scabies cases.

Prevalence of Scabies in the Covid-19 Pandemic Period and Determination of Risk Factors for Scabies: a Hospital-Based Cross-Sectional Study in Northeast Turkey

BACKGROUND

There is an increase in the incidence of scabies in Turkey, which started before the Covid-19 pandemic, and this situation is considered as an epidemic. With this study, we aimed to reveal the prevalence of scabies during the pandemic period and the risk factors that are effective in the transmission of scabies.

METHODS

Our study was performed as a cross-sectional study in 376 patients who applied to our dermatology outpatient clinic between 1st and 30th April 2021. Sociodemographic and socioeconomic characteristics, living space, health behavior, and health care utilization of the patients were questioned.

RESULTS

The prevalence of scabies was determined as 10.9%. Features such as sex, area of residence, age, formal education status, employment status, total income, number of shower, number of people per room, water source, and heating method, which were found to be significant as a result of the double test, were included in the logistic regression analysis. Scabies was found 2.728 times (CI 1.325-5.557) more in those who live in rural areas than those who live in urban areas, 2.714 times (CI 1.365-5.451) more in men than women, 2.707 times (CI 1.256-5.833) more in nonworking than working, 2.354 times (CI 1.057-5.243) more in those with less than 9 showers per month than those with 9 or more showers per month.

CONCLUSION

During the Covid-19 pandemic period, the prevalence of scabies in Turkey is increasing and it is becoming a serious health problem. Our study emphasizes this increase and determines the risk factors for transmission.

Optimal Control and Cost-Effective Analysis of a Scabies Model with Direct and Indirect Transmissions

Scabies is caused by sarcoptes scabiei var. hominis, which is also referred to as itch mice. The disease is transmitted through direct contact with an infected person, or from contact with infested bedding or clothing. In this paper, a mathematical model for the spread of scabies was proposed and analyzed. Sensitivity analysis of the model parameters was carried out. Optimal control theory was applied to our proposed model, with the controls representing treatment and vaccination. Our aim was to minimize cumulative infectious cases and susceptible individuals through treatment and vaccination, respectively. Pontryagin’s maximum principle was utilized to characterize the optimal levels of the two controls. The resulting optimality system was then solved numerically. The optimal control result was further highlighted by applying the results realized from the cost objective functional, the IAR, and the ICER.

Health care cost of crusted scabies in Aboriginal communities in the Northern Territory, Australia

Background

Crusted scabies is a debilitating dermatological condition. Although still relatively rare in the urban areas of Australia, rates of crusted scabies in remote Aboriginal communities in the Northern Territory (NT) are reported to be among the highest in the world.

Objective

To estimate the health system costs associated with diagnosing, treating and managing crusted scabies.

Methods

A disease pathway model was developed to identify the major phases of managing crusted scabies. In recognition of the higher resource use required to treat more severe cases, the pathway differentiates between crusted scabies severity grades. The disease pathway model was populated with data from a clinical audit of 42 crusted scabies patients diagnosed in the Top-End of Australia’s Northern Territory between July 1, 2016 and May 1, 2018. These data were combined with standard Australian unit costs to calculate the expected costs per patient over a 12-month period, as well as the overall population cost for treating crusted scabies.

Findings

The expected health care cost per patient diagnosed with crusted scabies is $35,418 Australian dollars (AUD) (95% CI: $27,000 to $43,800), resulting in an overall cost of $1,558,392AUD (95% CI: $1,188,000 to $1,927,200) for managing all patients diagnosed in the Northern Territory in a given year (2018). By far, the biggest component of the health care costs falls on the hospital system.

Discussion

This is the first cost-of-illness analysis for treating crusted scabies. Such analysis will be of value to policy makers and researchers by informing future evaluations of crusted scabies prevention programs and resource allocation decisions. Further research is needed on the wider costs of crusted scabies including non-financial impacts such as the loss in quality of life as well as the burden of care and loss of well-being for patients, families and communities.

Crusted scabies is characterised by thick skin crusting and fissuring and can lead to serious secondary infections and death from complications. Rates of crusted scabies in remote Aboriginal communities in the Northern Territory (NT) are among the highest in the world. Efforts are on the way in Australia to prevent, if not eliminate, crusted scabies. We use data from a clinical audit of 42 patients diagnosed with crusted scabies in the Top-End of the NT to estimate the health system costs associated with diagnosing, treating and managing crusted scabies for patients and their households. This cost of illness study can provide a valuable starting point for policy makers and evaluators in estimating the potential economic impact of crusted scabies prevention programs on health care service use and costs.

The national burden of scabies in Germany: a population-based approach using Internet search engine data

PURPOSE

Scabies is a World Health Organization-defined neglected tropical disease and a growing public health issue worldwide. It is difficult to obtain reliable data on prevalence due to the lack of standardized tests. The aim of this study was to assess scabies online search behavior in Germany to identify local differences using Google search volume.

METHODS

Google Ads Keyword Planner was used to investigate the scabies-related search volume for Germany as a whole, its 16 federal states, and 15 large cities for the period from January 2016 to December 2019. The identified search terms were qualitatively categorized and critically analyzed.

RESULTS

A total of 572 keywords with an overall search volume of 11,414,180 searches regarding scabies were identified in Germany. The number of searches was higher in winter than in summer, with a national peak in March 2018. Around 30.6% of the searches regarding scabies therapy (n = 978,420) were related to home remedies. Regarding body localization, most searches focused on the whole body (n = 109,050), followed by head (n = 89,360) and the genital area (n = 28,640).

CONCLUSIONS

The analysis of Google search data provides an overview of the populations' interest regarding scabies. The analysis can detect local peaks and assess the relevance of scabies at individual localizations of the body. The study highlighted current possible shortcomings in the therapy of scabies. It also underlined the importance of improving awareness regarding scabies so that affected individuals can consult a doctor earlier for treatment.

Scabies Knowledge Among Undergraduate Nursing Students in China: A Questionnaire Survey

PURPOSE

Scabies is a common, neglected, and a major health concern skin disease in the world. Improper care may produce a series of complications and even lead to the spread of diseases. Nursing students, as future health-care workers, are vital to the prevention and care of diseases. However, to date, few studies have focused on the basis of their disease cognition for scabies. This study aims to evaluate the level of undergraduate nursing students' awareness of scabies disease.

METHODS

A questionnaire survey was conducted among all undergraduate nursing students in Xi'an FanYi University, Xian, Shaanxi Province, China.

RESULTS

All the 132 undergraduate nursing students completed the questionnaire. The true ignorance rate of scabies in this survey was 82.6%. However, among the 56 students (42.4% of total) who thought they knew about the disease. Only 23 students (17.4% of the samples) had 75% or more satisfactory knowledge. Fewer students claimed that they had read about the itchy-mite-disease in books (N = 20, 15.2%). Compared with college textbooks (P-value < 0.05) and medical books (P-value < 0.05), other books (medical journals) provide more information about scabies. Nearly half of the students did not know that the scabies can be contagious. All students expressed their willingness to learn about scabies knowledge and participate in the diagnosis and treatment of scabies (100%).

CONCLUSION

This study shows that undergraduate nursing students have a poor level of knowledge about scabies. There is an urgent need to improve nursing students' awareness of scabies and increase their knowledge base, so as to strengthen the standardized nursing of scabies and reduce the prevalence of scabies.

Previous Long-term Care Facility Admission as a Risk Factor for Scabies in a Medical Facility

The study aimed to elucidate simple and effective risk factors for scabies infection in the medical environment for early detection and prevention of exposure to other patients and medical staff. We conducted a case-control study of patients who were diagnosed with scabies among hospitalized patients between 2008 and 2019 in an acute-care teaching hospital. Each case was matched according to sex and age with two randomly selected controls without scabies during hospitalization. Clinical characteristics of cases at the time of hospital admission were compared to those of the control group. The scabies group included 34 patients and 68 patients who were included in the control group. After adjusting for confounding factors, previous long-term care facility admission was only associated with scabies (adjusted odds ratio, 5.44; 95% confidence interval, 1.46-20.27; P = 0.012). Careful examination, particularly for patients with previous long-term care facility admission, might be useful for the early detection of scabies.

Transcriptome Analysis of Host Inflammatory Responses to the Ectoparasitic Mite Sarcoptes scabiei var. hominis

Scabies, a human skin infestation caused by the ectoparasitic mite Sarcoptes scabiei var. hominis, affects more than 200 million people globally. The prevailing knowledge of the disease process and host immune response mechanisms is limited. A better understanding of the host-parasite relationship is essential for the identification of novel vaccine and drug targets. Here we aimed to interrogate the transcriptomic profiles of mite-infested human skin biopsies with clinical manifestations of ordinary scabies subjects ("OS"; n = 05) and subjects naive to scabies ("control"; n = 03) using RNASeq data analysis. A combined clustering, network, and pathway mapping approach enabled us to identify key signaling events in the host immune and pro-inflammatory responses to S. scabiei infestation. The clustering patterns showed various differentially expressed genes including inflammatory responses and innate immunity genes (DEFB4A, IL-19, CXCL8, CSF3, SERPINB4, S100A7A, HRNR) and notably upregulation of the JAK-STAT pathway in scabies-infested samples. Mite-infested human skin biopsies (GSE178563) were compared with an ex-vivo porcine infested model (E-MTAB-6433) and human skin equivalents (GSE48459). Marked enrichment of immune response pathways (JAK-STAT signaling, IL-4 and IL-13 pathway, and Toll receptor cascade), chemokine ligands and receptors (CCL17, CCL18, CCL3L1, CCL3L3, CCR7), and cytokines (IL-13 and IL-20) were observed. Additionally, genes known for their role in psoriasis and atopic dermatitis were upregulated, e.g., IL-19. The detailed transcriptomic profile has provided an insight into molecular functions, biological processes, and immunological responses and increased our understanding about transcriptomic regulation of scabies in human.

Scabies in Spain? A comprehensive epidemiological picture

INTRODUCTION

Scabies is a neglected disease stablished worldwide with a fairy well determined incidence. In high-income countries, it often causes outbreaks affecting the residents and staff of institutions and long-term facilities, usually hard to detect and control due to the difficult diagnosis and notification delay. This study aim at characterizing the affected population, geographical distribution, and evolution of scabies in Spain from 1997-2019 as well as to describe the main environments of transmission using different data sources.

METHODS

We carried out a nationwide retrospective study using four databases, which record data from different perspectives: hospital admissions, patients attended at primary healthcare services, outbreaks, and occupational diseases. We described the main characteristics from each database and calculated annual incidences in order to evaluate temporal and geographical patterns. We also analyzed outbreaks and occupational settings to characterize the main transmission foci and applied Joinpoint regression models to detect trend changes.

RESULTS

The elderly was the most frequent collective among the hospital admitted patients and notified cases in outbreaks, while children and young adults were the most affected according to primary care databases. The majority of the outbreaks occurred in homes and nursing homes; however, the facilities with more cases per outbreak were military barracks, healthcare settings and nursing homes. Most occupational cases occurred also in healthcare and social services settings, being healthcare workers the most common affected professional group. We detected a decreasing trend in scabies admissions from 1997 to 2014 (annual percentage change -APC- = -11.2%) and an increasing trend from 2014 to 2017 (APC = 23.6%). Wide geographical differences were observed depending on the database explored.

DISCUSSION

An increasing trend in scabies admissions was observed in Spain since 2014, probably due to cutbacks in social services and healthcare in addition to worsen of living conditions as a result of the 2008 economic crisis, among other reasons. The main transmission foci were healthcare and social settings. Measures including enhancing epidemic studies and national registries, reinforcing clinical diagnosis and early detection of cases, hygiene improvements and training of the staff and wide implementation of scabies treatment (considering mass drug administration in institutions outbreaks) should be considered to reduce the impact of scabies among most vulnerable groups in Spain.

Dermoscopy, light microscopy, and real-time polymerase chain reaction for the diagnosis of scabies. Preliminary results

Introduction

Scabies is a widespread, contagious parasitic disease causing intense itching. Its detection is a significant problem while there are no internationally agreed standards.

Aim

To compare diagnostic methods: microscopy of skin scrapings, dermoscopy, and real-time polymerase chain reaction (PCR) of skin scrapings and wet skin swabs.

Material and methods

We included patients with clinical signs of scabies. After dermoscopic evaluation, scrapings were collected from skin lesions and assessed by light microscopy and real-time PCR. Wet skin swabs were also analysed by real-time PCR. Surveys on the presence and severity of pruritus and skin lesions were collected. Seventy-five skin scrapings and 41 wet swabs were examined by real-time PCR. Fifty-three patients completed the survey. All patients underwent dermoscopy and microscopy examinations. 6.67% were positive by microscopy, 10.7% by dermoscopy, 28.0% by real-time PCR from scrapings, and 36.6% when both scrapings and swabs were examined by real-time PCR. All microscopy-positive results were also positive by PCR.

Results

There was a correlation between real-time PCR from positive scrapings and pruritus (p = 0.023) and body surface area of lesions (p = 0.002), a correlation between copies from wet skin swabs and BSA of lesions (p = 0.002) in the whole group, and a correlation between copies of S. scabiei from scrapings and age (p = 0.038).

Conclusions

Real-time PCR testing of scrapings and dermoscopy are more effective than microscopy. Combined real-time PCR testing of scrapings and skin swabs seemed the most effective. Clinical signs alone should not be used as unambiguous criteria.

[Epidemiology of scabies in Germany: multisource analysis of primary and secondary data]

BACKGROUND

Scabies is one of the most common and, in terms of burden of disease, one of the most significant skin diseases worldwide. In Germany, an increase in cases is currently being discussed, for which reliable data have been lacking until now.

OBJECTIVES

The goal is to clarify the prevalence and treatment of scabies in Germany.

MATERIALS AND METHODS

Multisource analyses of treatment data from a nationwide statutory health insurance company, the Federal Statistical Office and company skin screenings.

RESULTS

In Germany, the number of cases of scabies has been rising since 2009 and especially since 2014. In the outpatient setting, there was an increase of 52.8% to around 128,000 treatment cases between 2010 and 2015. Currently, more than 11,000 inpatient cases are documented annually in Germany with scabies as the main diagnosis (ICD-10 B86). The increase between 2010 and 2016 was about 306%. The main outpatient specialist groups providing care are dermatologists and general practitioners, while in the inpatient sector treatment is provided by departments of dermatology, paediatrics and internal medicine.

CONCLUSION

Due to the aforementioned development of prevalence and incidence, the need for care will remain at a high level in the future, which suggests an increased need for education and early detection.

Scabies in remote Aboriginal and Torres Strait Islander populations in Australia: A narrative review

Scabies has recently gained international attention, with the World Health Organization (WHO) recognizing it as a neglected tropical disease. The International Alliance for the Control of Scabies recently formed as a partnership of more than 15 different countries, with an aim to lead a consistent and collaborative approach to preventing and controlling scabies globally. Scabies is most prevalent in low-resource and low socioeconomic areas that experience overcrowding and has a particularly high prevalence in children, with an estimated 5% to 10% in endemic countries. Scabies is widespread in remote Aboriginal and Torres Strait Islander communities in Australia with the prevalence of scabies in Aboriginal and Torres Strait Islander children in remote communities estimated to be as high as 33%, making it the region with the third highest prevalence in the world. This population group also have very high rates of secondary complications of scabies such as impetigo, poststreptococcal glomerulonephritis (PSGN), and rheumatic heart disease (RHD). This article is a narrative review of scabies in remote Aboriginal and Torres Strait Islander populations in Australia, including clinical manifestations of disease and current treatment options and guidelines. We discuss traditional approaches to prevention and control as well as suggestions for future interventions including revising Australian treatment guidelines to widen the use of oral ivermectin in high-risk groups or as a first-line treatment.

Impact of socio-demographic factors on knowledge, attitude and practices toward scabies among syrian refugees in Jordan: A prospective cross sectional study

Background

Scabies is one of the prevalent dermatological conditions, accounting for a substantial proportion of skin diseases in developing countries. It represents a significant health challenge when an outbreak appears in homecare and refugee camps as it may lead to enormous morbidity and high treatment costs. Because Scabies can be easily prevented through education, the purpose of this study was to assess the impact of socio-demographic factors on the level of knowledge, attitude, and practices among Syrian refugees in Jordan's northern region.

Methods

A prospective cross-sectional study was conducted among Syrian refugees attending primary health centers in northern Jordan, Ramtha, Mafraq, and Irbid, from February 2021 to May 2021. The targeted population was adult Syrian refugees above the age of 18. Two thousand participants were included in this study using simple random selection. The study questionnaire included socio-demographic characteristics and knowledge questions such as hearing about Scabies, causes of Scabies, signs and symptoms of Scabies, and its way of transmission. The data was analyzed using (SPSS) version 25.

Results

Females with a mean age of 37.9 years old comprised the majority of the participants. The majority of the participants were married and had intermediate levels of education. The knowledge about Scabies lacked among the majority of the respondents (N = 1259); 321 respondents had moderate knowledge, while only 650 had good knowledge. A statistically significant association was found between knowledge scores and all demographic characteristics, including gender, marital status, income, and educational level.

Conclusion

The general knowledge about Scabies among Syrian refugees is relatively low, with 1259 out of 2000 participants having a bad knowledge score. Moreover, the level of knowledge, attitude, and practices toward Scabies is highly affected by the demographic factors of the Syrian refugees' Health education for refugees is needed to improve their knowledge and help implement prevention programs.

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Scabies is quite a common medical problem among Syrian Refugees in Jordan.

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The socio-demographics of Syrian Refugees affect the level of knowledge and attitude toward scabies infestation.

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The level of knowledge regarding scabies infestation is poor among Syrian Refugees in Jordan.

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Health education for refugees is needed to improve their knowledge and help implement prevention programs.

Scabies as a part of the World Health Organization roadmap for neglected tropical diseases 2021-2030: what we know and what we need to do for global control

Background

Scabies is an under-recognized global health problem with an unacceptably high prevalence in many settings worldwide. Fortunately, the World Health Organization (WHO) has formally designated scabies as a neglected tropical disease in 2017, in the hope of increasing awareness and encouraging efforts to eradicate it. Also, scabies has recently been included as part of the WHO roadmap for neglected tropical diseases 2021–2030, aimed at ending the neglect to attain the Sustainable Development Goals.

Main abstract body

This review article places scabies in focus. The literature was reviewed to explore discussions on controversial issues in scabies control, with the aim of clarifying whether global control of scabies is a feasible and worthwhile objective. The existing status of scabies and its burden are discussed along with future prospects for its global control. The article investigates the feasibility of scabies control and provides updates on the various impediments to this goal, such as challenges related to transmission, diagnosis, treatment, and vaccine development. Also examined are relevant research needs, success factors, and reasons for failure. This article aims to increase the global awareness of scabies and promote discussion, enhance coordinated international efforts, and ultimately, enact change at the national and worldwide levels toward the control of this preventable disease of the poor.

Conclusion

Despite the current challenges, scabies control is now within reach. With sustained interventions, continuous resources, and sincere commitment and support, scabies global control appears to be a worthwhile, realistic goal that is potentially achievable in the not so distant future.

Sarcoptes Infestation. What Is Already Known, and What Is New about Scabies at the Beginning of the Third Decade of the 21st Century?

Currently, there are three known subtypes of scabies: ordinary, crusted, and bullous. The worldwide prevalence of scabies remains high in the 21st century. To decrease the social, economic, and psychological impact on the enormous population infected, a lot of important work has been completed over the last 20 years concerning the management of scabies. For example, a standardization of guidelines for the treatment of scabies has been completed and programs have been designed for the prevention and treatment in endemic populations, called mass drug administrations. Unfortunately, these only apply to the ordinary form of scabies. Moreover, resistance to the drugs currently used in treatment is growing, which imposes the need to search for new treatments. For this purpose, new acaricides are being developed to enhance the therapeutic options for the patients' benefit and effectively treat this disease. There is also the necessity for prevention before the development of scabies. An effective vaccine has the potential to protect people before this disease, especially in endemic areas. Unfortunately, there are no such vaccines against Sarcoptes yet.

Mass drug administration campaigns for scabies and impetigo: protocol for a systematic review and meta-analysis

Introduction

Scabies is recognised as a neglected tropical disease, disproportionately affecting the most vulnerable populations around the world. Impetigo often occurs secondarily to scabies. Several studies have explored mass drug administration (MDA) programmes, with some showing positive outcomes-but a systematic evaluation of such studies is yet to be reported. The main aim of this systematic review is to generate comprehensive evidence on the effect and feasibility of MDA programmes in reducing the burden of scabies and impetigo.

Methods and analysis

A systematic review and meta-analysis will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. Electronic databases to be searched will include CINAHL EBSCOhost, Medline Ovid, ProQuest, Science Direct, PubMed and SCOPUS. In addition, grey literature will be explored via the Australian Institute of Health and Welfare, Australian Indigenous HealthInfoNet, Informit, OaIster database and WHO. No language restrictions will be applied. All treatment studies following an MDA protocol, including randomised/quasi-controlled trials, and prospective before-after interventional studies, will be considered. The main outcome is the change in prevalence of scabies and impetigo The Cochrane collaboration risk of bias assessment tool will be used for assessing the methodological quality of studies. A random-effect restricted maximum likelihood meta-analysis will be performed to generate pooled effect (OR) using STATA V.16. Appropriate statistical tests will be carried out to quantify heterogeneity between studies and publication bias.

Ethics and dissemination

Ethical approval is not required since data will be extracted from published works. The findings will be communicated to the scientific community through a peer-reviewed journal publication. This systematic review will present an evidence on the effect of MDA interventions on scabies and impetigo, which is instrumental to obtain a clear understanding of the treatments widely used in these programmes.

PROSPERO registration number

CRD42020169544.

A facility and community-based assessment of scabies in rural Malawi

BACKGROUND

Scabies is a neglected tropical disease of the skin, causing severe itching, stigmatizing skin lesions and systemic complications. Since 2015, the DerMalawi project provide an integrated skin diseases clinics and Tele-dermatology care in Malawi. Clinic based data suggested a progressive increase in scabies cases observed. To better identify and treat individuals with scabies in the region, we shifted from a clinic-based model to a community based outreach programme.

METHODOLOGY/PRINCIPAL FINDINGS

From May 2015, DerMalawi project provide integrated skin diseases and Tele-dermatological care in the Nkhotakota and Salima health districts in Malawi. Demographic and clinical data of all patients personally attended are recorded. Due to a progressive increase in the number of cases of scabies the project shifted to a community-based outreach programme. For the community outreach activities, we conducted three visits between 2018 to 2019 and undertook screening in schools and villages of Alinafe Hospital catchment area. Treatment was offered for all the cases and school or household contacts. Scabies increased from 2.9% to 39.2% of all cases seen by the DerMalawi project at clinics between 2015 to 2018. During the community-based activities approximately 50% of the population was assessed in each of three visits. The prevalence of scabies was similar in the first two rounds, 15.4% (2392) at the first visit and 17.2% at the second visit. The prevalence of scabies appeared to be lower (2.4%) at the third visit. The prevalence of impetigo appeared unchanged and was 6.7% at the first visit and 5.2% at the final visit.

CONCLUSIONS/SIGNIFICANCE

Prevalence of scabies in our setting was very high suggesting that scabies is a major public health problem in parts of Malawi. Further work is required to more accurately assess the burden of disease and develop appropriate public health strategies for its control.

Paediatrics: how to manage scabies

This narrative review addresses scabies, a highly contagious, pruritic infestation of the skin caused by the mite Sarcoptes scabiei var hominis. Scabies is a common disorder that has a prevalence worldwide estimated to be between 200 and 300 million cases per year. Infestation is of greatest concern in children, the elderly, immunocompromised people and resource-poor endemic populations at risk of chronic complications. A diagnosis of scabies involves a clinical suspicion, a detailed targeted history, clinical examination and contact tracing. Dermoscopy and microscopy, where available, is confirmatory. Due to its infectivity and transmissibility, the management for scabies requires a multimodal approach: topical antiscabetic agents are the first line for most cases of childhood classic scabies and their contacts, which must also be identified and treated to prevent treatment failure and reacquisition. Environmental strategies to control fomite-related reinfestation are also recommended. Oral ivermectin, where available, is reserved for use in high-risk cases in children or in mass drug administration programmes in endemic communities. The prevention of downstream complications of scabies includes surveillance, early identification and prompt treatment for secondary bacterial infections, often superficial but can be serious and invasive with associated chronic morbidity and mortality. Post-scabetic itch and psychosocial stigma are typical sequelae of the scabies mite infestation. The early identification of patients with scabies and treatment of their contacts reduces community transmission. Although time consuming and labour intensive for caregivers, the implementation of appropriate treatment strategies usually results in prompt cure for the child and their contacts. Here, we provide a summary of treatments and recommendations for the management of paediatric scabies.

Recent advances in understanding and treating scabies

Scabies is an infestation of the skin caused by the mite Sarcoptes scabiei. In 2017, scabies was recognised by the World Health Organisation as a disease of public importance and was consequently added to the list of neglected tropical diseases. An estimated 200 million people currently have scabies worldwide. Scabies is endemic in many developing countries, with the highest prevalence being in hot, humid climates such as the Pacific and Latin American regions. Scabies causes a host immune response which is intensely itchy. Scratching of the lesions can lead to secondary bacterial infections of the skin, such as impetigo, most commonly caused by Streptococcus pyogenes or Staphylococcus aureus. This can have fatal consequences, such as septicaemia, glomerulonephritis, and rheumatic heart disease. Advances over the past 5 years indicate that mass drug administration is an effective strategy to treat scabies. This review will outline advances in the mite biology, epidemiological understanding, diagnosis, and treatment of scabies.

Scabies and impetigo in Samoa: A school-based clinical and molecular epidemiological study

Background

Common infections of the skin such as impetigo and scabies represent a large burden of disease globally, being particularly prevalent in tropical and resource-limited settings. Efforts to address these infections through mass drug administrations have recently been shown as efficacious and safe. In Samoa, a Pacific Island nation, there is a marked lack of epidemiological data for these neglected tropical diseases, or appreciation of their drivers in this setting.

Methods

An observational, cross-sectional survey of children aged between 4 and 15 years attending primary schools in rural areas of Upolu Island, Samoa was carried out to assess the prevalence of impetigo and scabies in schoolchildren residing in rural Samoa, integrated with descriptive epidemiological and microbial genomic data. A phylogenetic assessment of local Staphylococcus aureus isolated from Samoan schoolchildren was performed to estimate putative community transmission.

Findings

In this survey, the prevalence of impetigo observed in Samoan schoolchildren was one of the highest described globally (57•1%, 95% CI [53•8-60•5%], 476/833). Associations between active impetigo and age and gender were noted, with younger children and males more commonly affected (aOR2•8 [1•8-4•7]and aOR1•8 [1•3-2•5], respectively). The prevalence of scabies was similar to that seen in other South Pacific island countries (14•4%, 95% CI [12•2-17•0%], 120/833). Transmission of S. aureus was predicted, primarily between those children attending the same school. Carriage of S. pyogenes was notably low, with pharyngeal carriage observed in less than 2% of schoolchildren, consistent with earlier studies from Samoa.

Interpretation

This study describes a considerable burden of disease attributed to impetigo and scabies in Samoa. These findings will be valuable in addressing the public health challenge posed by these conditions, providing baseline prevalence data and highlighting practical strategies to reduce transmission of relevant microbes and parasites in this setting.

Tala Tomua

O a'afiaga o le pa'u i fa'ama'i o le po'u (impetigo) ma le utu o le pa'u (scabies), ua tele naua le fanau ua maua ai i le pasefika, ma le lalolagi atoa. O fuafuaga vaai mamao ma polokalame e fofoina ai nei faafitauli, e aofia ai le inumaga o fualaau e tapeina ai nei fa'ama'i, ua aliali mai ai e mafai ona faatamaia nei fa'ama'i. E le o tele ni tusitusiga ma faamaumauga i totonu o Samoa, pe ta'atele nei fa'amai o le pa'u pe leai. Ona o le le faatauaina o nei fa'ama'i, e le o iloa fo'i ni mafuaga ma nisi tulaga e faateleina ai nei fa'ama'i o le pa'u i Samoa.

Faatinoina o le suesuega

O le suesuega faasaenisi i le fanau aoga i le va o le 4 ma le 15 tausaga o loo ao'oga i le tulaga lua i nisi o nu'u i tua i Upolu, na faatinoina ai suesuega lea, ia suesueina ai le aotelega ma fainumera o le fanau ua maua i fa'ama'I o le po'u (impetigo) ma le utu o le pa'u (scabies). O lenei foi suesuega, na fia iloa ai fo'i po'o a ituaiga siama eseese o loo maua i luga o pa'u ma tino o le fanau aoga, ina ia iloa ai foi auala ua pipisi ai nei siama mai le isi tamaitiiti i le isi, ona mafua ai lea o nei fa'ama'i o le pa'u.

Tanuuga o le suesuega

Ua faailoa mai i le suesuega, le ta'atele o le fa'ama'i o le po'u (impetigo) ua maua ai le fanau aoga (57%), i aoga na faia ai le suesuega. O se fainumera ua maualuga tele i le lalolagi atoa. E toatele atu nisi o le fanau laiti (younger) ma tama (male) e maua i le po'u nai lo isi tamaiti. O le fainumera o le utu o le pa'u (scabies) (14·4%) e tai tutusa lava ma isi motu o le Pasefika. O le feaveaina o le siama faapitoa (staph aureus) ua tupu lea i le fanau ua ao'oga i le aoga e tasi. E le toatele foi nisi o le fanau (2%) na maua i le siama faapitoa o le fa'ai (strep pyogenes) e ona mafua ai le fiva rumatika. O lenei fainumera ua tai tutusa ma suesuega faasaenisi na fai muamua i Samoa.

Aotelega

O le aotelega la o lenei suesuega faasaenisi, ua faailoaina mai ai le tele naua o le fa'ama'i o le pa'u, o po'u (impetigo) ma le utu o le pa'u (scabies) i Samoa nei. O nei foi suesuega o le a aoga tele ini polokalame ma ni fuafuaga mamao e fa'afoisia ai nei faafitauli i le soifua maloloina o le fanau i Samoa. O le a avea foi nei fainumera e faamaumauina mo le silafia e le atunuu ma le soifua maloloina, le ta'atele o nei fa'amai o le pa'u, mo le tapenaina o ni fofo talafeagai ise taimi o i luma, ina ia faaitiitina ai le pipisi o nei siami i fanau ao'oga i Samoa.

The 2020 International Alliance for the Control of Scabies Consensus Criteria for the Diagnosis of Scabies

BACKGROUND

Scabies is a common parasitic skin condition that causes considerable morbidity globally. Clinical and epidemiological research for scabies has been limited by a lack of standardization of diagnostic methods.

OBJECTIVES

To develop consensus criteria for the diagnosis of common scabies that could be implemented in a variety of settings.

METHODS

Consensus diagnostic criteria were developed through a Delphi study with international experts. Detailed recommendations were collected from the expert panel to define the criteria features and guide their implementation. These comments were then combined with a comprehensive review of the available literature and the opinion of an expanded group of international experts to develop detailed, evidence-based definitions and diagnostic methods.

RESULTS

The 2020 International Alliance for the Control of Scabies (IACS) Consensus Criteria for the Diagnosis of Scabies include three levels of diagnostic certainty and eight subcategories. Confirmed scabies (level A) requires direct visualization of the mite or its products. Clinical scabies (level B) and suspected scabies (level C) rely on clinical assessment of signs and symptoms. Evidence-based, consensus methods for microscopy, visualization and clinical symptoms and signs were developed, along with a media library.

CONCLUSIONS

The 2020 IACS Criteria represent a pragmatic yet robust set of diagnostic features and methods. The criteria may be implemented in a range of research, public health and clinical settings by selecting the appropriate diagnostic levels and subcategories. These criteria may provide greater consistency and standardization for scabies diagnosis. Validation studies, development of training materials and development of survey methods are now required. What is already known about this topic? The diagnosis of scabies is limited by the lack of accurate, objective tests. Microscopy of skin scrapings can confirm the diagnosis, but it is insensitive, invasive and often impractical. Diagnosis usually relies on clinical assessment, although visualization using dermoscopy is becoming increasingly common. These diagnostic methods have not been standardized, hampering the interpretation of findings from clinical research and epidemiological surveys, and the development of scabies control strategies. What does this study add? International consensus diagnostic criteria for common scabies were developed through a Delphi study with global experts. The 2020 International Alliance for the Control of Scabies (IACS) Criteria categorize diagnosis at three levels of diagnostic certainty (confirmed, clinical and suspected scabies) and eight subcategories, and can be adapted to a range of research and public health settings. Detailed definitions and figures are included to aid training and implementation. The 2020 IACS Criteria may facilitate the standardization of scabies diagnosis.

Preliminary detection of mites and coccidia with their zoonotic potential in meat-farmed rabbits in three districts in Selangor, Malaysia

Mites infestation and gastrointestinal parasites including coccidia are common problems reported in pets, petting farms and farmed practices. Sarcoptes sp. and Cheyletiella sp. could be a potential zoonosis from rabbits to human. Detection of mites and coccidia with their zoonotic potential in meat-farmed rabbits from three (3) commercial farms in Selangor were investigated. Tape impression, fur pluck, skin scraping and ear swab tests were used for mites detection and faecal samples was used for coccidia examination by using McMaster's technique and the identification of Eimeria spp. was further analysed by sporulation technique. The overall prevalence of mites and Eimeria spp. (oocysts) in rabbits were 51.85% ± 0.38 (standard deviation; S.D.) and 76.47% ± 0.42 respectively. Sarcoptes scabiei was the most frequent mite found (25.92% ± 0.44), followed by Cheyletiella parasitovorax and Psoroptes cuniculi. Nine Eimeria spp. were identified and the oocysts of E. perforans shows the highest prevalence (64.71% ± 3.97) followed by E. exigua, E. coecicola, E. magna, E. flavescens, E. irresidua, E. intestinalis, E. media and E. stiedai. There was a significant difference (p = 0.013) where large-scale farm has a higher prevalence of coccidia than small scale farms apparently due to the excessive stocking density as coccidia are easily transmitted among rabbits through ingestion of sporulated oocysts. In conclusion, mites and coccidia are commonly present in the commercial rabbit farms, thus control and preventive measures should be executed to reduce the incidence of parasites. The zoonotic mites Sarcoptes scabiei and Cheyletiella parasitovorax detected in this study could be regarded as a public health concern especially when handling the rabbit.

An Increasing Scabies Incidence in Croatia: A Call for Coordinated Action Among Dermatologists, Physicians and Epidemiologists

Introduction

The aim of our study was to examine the scabies incidence in the Croatian population and to analyse potential related factors.

Methods

This mixed ecological study is based on a retrospective medical record review. National data from communicable disease reports was sourced and analysed for an 11-year period (2007-2017), with more focus on the period 2014-2017. Descriptive statistics were used to calculate trends. Differences between the groups were studied using Chi-square test and Kendall's tau (τ) correlation coefficient. Levels of significance were set at p<0.05 or p<0.01.

Results

From 2007 to 2017, scabies infestation in Croatia increased by 6-fold, particularly affecting children and young adults (19 years or younger). In the period 2014-2017, border counties which are part of migration flows were the counties with the highest average scabies incidences. A linear trend of increase in the number of tourists, immigrants and scabies infestations was noted on the national level for the analysed period, although a significant association was not observed. Regarding outbreaks of scabies within institutions, more than 80% of outbreaks occurred in institutions for adults. In the capital, Zagreb, the crude incidence rate increased 3-fold between 2014 and 2017.

Conclusions

The increased incidence of scabies, large disparities between counties, and prolonged outbreaks within families due to under-recognition and misdiagnoses points to a need for increased awareness among health practitioners. To the best of our knowledge, this is the first recent epidemiologic analysis on this topic, not only in Croatia but within the wider geographic region as well.

A community-based validation of the International Alliance for the Control of Scabies Consensus Criteria by expert and non-expert examiners in Liberia

Background

The International Alliance for the Control of Scabies (IACS) recently published expert consensus criteria for scabies diagnosis. Formal validation of these criteria is needed to guide implementation. We conducted a study to provide detailed description of the morphology and distribution of scabies lesions as assessed by dermatologists and validate the IACS criteria for diagnosis by both expert and non-expert examiners.

Methods

Participants from a community in Monrovia, Liberia, were independently assessed by two dermatologists and six non-expert examiners. Lesion morphology and distribution were documented based on the dermatologist examination. Diagnoses were classified by IACS criteria and the sensitivity and specificity of non-expert examiner assessments calculated.

Results

Papules were the most common lesions (97.8%). Burrows were found in just under half (46.7%) and dermatoscopy was positive in a minority (13.3%). Scabies lesions were found in all body regions but more than 90% of patients could have been diagnosed by an examination of only the limbs. Severity of itch was associated with lesion number (p = 0.003). The sensitivity of non-expert examiners to detect typical scabies ranged between 69–83% and specificity 70–96%. The sensitivity of non-expert examiners was higher in more extensive disease (78–94%).

Conclusions

The IACS criteria proved a valid tool for scabies diagnosis. For the purposes of implementation papules and burrows represent truly ‘typical’ scabies lesions.

Non-expert examiners are able to diagnose scabies with a high degree of accuracy, demonstrating they could form a key component in population-level control strategies.

Scabies is a very common skin condition in both high- and low-income settings with hundreds of millions of people affected each year. Recently standardised criteria have been proposed to help improve the quality of scabies diagnosis, in particular in low income settings where the access to a skin specialist is very limited.

In this study, conducted in Liberia, expert examiners conducted a thorough examination and recorded what different types of skin problems they found in participants with and without scabies. We then compared the accuracy of a diagnosis of scabies made by dermatologists to that made by non-specialist healthcare workers who had received a short training course over three days.

We found that papules were the most common type of scabies lesion and were found in almost every single patient with scabies. A second type of skin lesion called a burrow was the next most common and was found in just under half of the participants. Other types of scabies lesions which have been described were rare in this study. We found that after the short training course the non-specialists were able to detect the majority of the cases of scabies correctly.

Our study has helped provide detailed data on exactly what types of skin changes are typical of scabies and demonstrated how short training programmes can help improve the skill of non-specialist examiners in diagnosing scabies.

Estimating the global burden of scabies: what else do we need?

Scabies is one of the most common disorders identified in any estimate of global skin disease prevalence. Furthermore, quantifying its impact on individuals and societies has been problematic. There has been a lack of clear case definitions and laboratory tests. There have been few epidemiological studies, particularly those focusing on low-income countries, variation in prevalence within high-income countries, or estimates of the effect of scabies on health beyond the skin, such as renal disease or mental wellbeing. Economic studies are also lacking. However, the new strategy of integrating surveillance for skin Neglected Tropical Diseases may well produce advancements on these issues, in addition to providing an overarching structure for health improvement and disease control.

Classic and Non-classic (Surrepticius) Scabies: Diagnostic and Treatment Considerations

The morphology of scabies, a mite infestation of worldwide proportion, is characterized by a variety of cutaneous lesions. Patients with classic scabies present with characteristic burrows often located on the web spaces of the fingers and toes. Scabies surrepticius refers to the non-classic atypical presentation of scabies; establishing the diagnosis of scabies in these individuals can be difficult. To facilitate the diagnosis of scabies, criteria have been proposed by the International Alliance for the Control of Scabies (IACS). These criteria are intended for scabies research; however, they can be utilized by clinicians to establish either a confirmed diagnosis, a clinical diagnosis or a suspected diagnosis of scabies. Visualization of mites, eggs or feces is necessary for a confirmed diagnosis of scabies. A clinical diagnosis can be established by observation of either genital lesions in men or burrows or classically distributed classical lesions in individuals with two historic features: pruritus and close contact with an individual who itches and has classically distributed classical scabetic lesions. The clinical features and management of a woman residing in an assisted living environment with a confirmed diagnosis of scabies and a man with a clinical diagnosis of scabies are described. The criteria for the suspected diagnosis of scabies require either one historic feature and typical lesions in a typical distribution or both historic features and the presence of atypical lesions or an atypical distribution of the skin lesions. Once the diagnosis of scabies is established, not only the patient but also close contacts should receive treatment with either a topical medication (such as permethrin 5% cream) or a systemic drug (ivermectin) or both. The number and frequency of treatments are variable; classic scabies typically is managed with a total of two treatments performed weekly to biweekly. Patients with crusted scabies usually require multiple topical and oral antiscabetic treatments in addition to topical keratolytic therapy. Bacterial impetiginization or infection (most commonly by Staphylococcus aureus or Streptococcus pyogenes) can complicate scabies infestation and potentially result in cellulitis, abscess, sepsis, rheumatic fever, rheumatic heart disease and post-streptococcal glomerulonephritis; therefore, in some patients, systemic antimicrobial therapy may be necessary in addition to scabies-directed treatment. In addition to systemic antihistamines, oral and/or topical corticosteroids may be used to provide symptomatic pruritus relief once the diagnosis of scabies has been established and mite-directed treatment has been initiated. The clinician should consider several potential causes (such as inadequate treatment, reinfection, mite resistance, delusions of parasitosis and the development of a new non-scabetic dermatosis) in scabies patients who fail to respond to treatment with a topical or oral scabicide therapy.

Perceptions, attitudes and practices towards scabies in communities on the Bijagós Islands, Guinea-Bissau

BACKGROUND

Scabies is highly endemic among impoverished populations and has been recently included in the WHO's list of neglected tropical diseases (NTDs). Community support and behavioural changes are essential for the success of control interventions. This study aimed to explore beliefs, prevention attitudes and healthcare-seeking behaviours towards scabies in the Bijagós Archipelago of Guinea-Bissau.

METHODS

Data were collected through two methods. Community key informants (community members, community health workers, healthcare workers and traditional healers) were interviewed using snowball sampling. A questionnaire covering perceptions, attitudes and practices was administered to community members using random cluster sampling. Thematic analysis of qualitative data was applied to identify themes. Descriptive statistics were used for quantitative data analysis.

RESULTS

There was a satisfactory awareness about scabies, but perceptions about disease causation and transmission were imprecise. Misconceptions about personal hygiene as the primary measure for scabies prevention were recurrent. Some participants recognised the importance of early treatment to interrupt transmission. Treatment of close contacts was not considered important. Costs were the main determining factor for treatment choice between traditional healer and the local health centre. Late presentation and delayed treatment were common and associated with poverty and stigmatisation. Scabies impaired quality of life by affecting social interactions, health, fitness to work and school attendance.

CONCLUSIONS

There is a need to improve education, recognition, management and affordable access to treatment. Community education, healthcare workers' training and skin NTD integrated control programmes should address the challenges highlighted in this study.

[Urological infections and migration]

In the context of refugee migrations infectious diseases are being more frequently diagnosed, which the responsible physicians as well as urologists have never seen before. This is due to the poorer health and hygiene conditions in the country of origin, during the flight and in the refugee camps. In Europe increasing incidences of tuberculosis, schistosomiasis and scabies have recently been observed. Tuberculosis and schistosomiasis are often accompanied by unspecific symptoms or can resemble normally encountered urological diseases. Due to the highly contagious nature of scabies, a screening of new arrivals is recommended. A timely differential diagnostic inclusion of these disease patterns is enormously important. Despite the reduction in the numbers of asylum applications in Germany, a higher number of unregistered migrants is generally assumed, who also elude the healthcare system and can therefore contribute to the spread of these rare infectious diseases.

The diagnosis of scabies by non-expert examiners: A study of diagnostic accuracy

Background

Although scabies is estimated to be one of the most common skin conditions globally, prevalence data is not available in most settings. Disease mapping is required to develop and monitor successful control programs. Non-expert health workers are likely to play an important role in scabies mapping activities in endemic settings.

Methodology

Four non-expert health workers were trained in the diagnosis of scabies and impetigo. The health worker diagnosis was compared to a reference consensus diagnosis of two doctors experienced in diagnosis. The study was conducted in a primary school in Gizo, Solomon Islands, in August 2018. The six examiners consecutively assessed school students, blinded to each other’s findings. Training and diagnostic procedures followed criteria for scabies diagnosis established by the International Alliance for the Control of Scabies in 2018.

Principal findings

Amongst the 171 students who underwent clinical assessment the prevalence of scabies and impetigo according to the reference standard was 55% and 45% respectively. Sensitivity of the non-expert health workers’ diagnosis compared to the reference standard was 55.3% for scabies (95% confidence interval [CI], 50.1–60.4) with a specificity of 89.9% (95% CI 86–93.1) and 52.6% for impetigo (95% CI 46.9–58.3) with a specificity 97.8% (95% CI 95.7–99). Sensitivity for moderate to severe scabies was 93.5% (95% CI 86.3–97.6) with a specificity of 74% (95% CI 70.2–77.5).

Conclusions

Following brief training, the diagnostic accuracy of non-expert health workers for scabies and impetigo was promising, especially for moderate to severe disease. Modifications to training and processes are recommended to further improve accuracy. The diagnosis by non-expert health workers may be acceptable for scabies and impetigo mapping in endemic areas.

Scabies is a parasitic infection that leads to significant morbidity worldwide. Mapping of scabies prevalence would improve the understanding of the true burden of disease and the need for control programs in specific countries and regions. The diagnosis of scabies in low resource settings, where the disease is most prevalent, is reliant on clinical examination. A task shifting approach, utilizing local health staff, could substantially increase the feasibility to undertake mapping surveys in low-resource settings. In this study, we aimed to evaluate the diagnostic accuracy of clinical assessment of local health workers following brief training. Our study found that these non-expert health workers could diagnose scabies with moderate accuracy and diagnose more severe disease with high accuracy. Further work is needed to develop standardized training packages to ensure a high level of diagnostic accuracy by non-expert health workers.

High-throughput metagenome analysis of the Sarcoptes scabiei internal microbiota and in-situ identification of intestinal Streptomyces sp

Multiple parasitic arthropods of medical importance depend on symbiotic bacteria. While the link between scabies and secondary bacterial infections causing post infective complications of Group A streptococcal and staphylococcal pyoderma is increasingly recognized, very little is known about the microbiota of Sarcoptes scabiei. Here we analyze adult female mite and egg metagenome datasets. The majority of adult mite bacterial reads matched with Enterobacteriaceae (phylum Proteobacteria), followed by Corynebacteriaceae (phylum Actinobacteria). Klebsiella was the most dominant genus (78%) and Corynebacterium constituted 9% of the assigned sequences. Scabies mite eggs had a more diverse microbial composition with sequences from Proteobacteria being the most dominant (75%), while Actinobacteria, Bacteroidetes and Firmicutes accounted for 23% of the egg microbiome sequences. DNA sequences of a potential endosymbiont, namely Streptomyces, were identified in the metagenome sequence data of both life stages. The presence of Streptomyces was confirmed by conventional PCR. Digital droplet PCR indicated higher Streptomyces numbers in adult mites compared to eggs. Streptomyces were localized histologically in the scabies mite gut and faecal pellets by Fluorescent In Situ Hybridization (FISH). Streptomyces may have essential symbiotic roles in the scabies parasite intestinal system requiring further investigation.

Ectoparasites: Scabies

Scabies is an ectoparasitic dermatosis caused by Sarcoptes scabiei var. hominis and is a public health issue in all countries regardless of socioeconomic status. In high-income countries, delays in diagnosis can lead to institutional outbreaks; in low- and middle-income countries, poor access to health care contributes to disease undertreatment and long-term systemic sequelae. With scabies now recognized as a neglected tropical disease by the World Health Organization, increased awareness and systematic efforts are addressing gaps in diagnosis and treatment that impede scabies control. This review summarizes the available data and provides an update on scabies epidemiology, clinical features, diagnosis, management, and public health considerations.

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.