Scabies and impetigo prevalence and risk factors in Fiji: a national survey

Randomized Trial of Community Treatment With Azithromycin and Ivermectin Mass Drug Administration for Control of Scabies and Impetigo

Background

Scabies is a public health problem in many countries, with impetigo and its complications important consequences. Ivermectin based mass drug administration (MDA) reduces the prevalence of scabies and, to a lesser extent, impetigo. We studied the impact of co-administering azithromycin on the prevalence of impetigo and antimicrobial resistance.

Methods

Six communities were randomized to receive either ivermectin-based MDA or ivermectin-based MDA co-administered with azithromycin. We measured scabies and impetigo prevalence at baseline and 12 months. We collected impetigo lesions swabs at baseline, 3 and 12 months to detect antimicrobial resistance.

Results

At baseline, scabies and impetigo prevalences were 11.8% and 10.1% in the ivermectin-only arm and 9.2% and 12.1% in the combined treatment arm. At 12 months, the prevalences had fallen to 1.0% and 2.5% in the ivermectin-only arm and 0.7% and 3.3% in the combined treatment arm. The proportion of impetigo lesions containing Staphylococcus aureus detected did not change (80% at baseline vs 86% at 12 months; no significant difference between arms) but the proportion containing pyogenic streptococci fell significantly (63% vs 23%, P < .01). At 3 months, 53% (8/15) of S. aureus isolates were macrolide-resistant in the combined treatment arm, but no resistant strains (0/13) were detected at 12 months.

Conclusions

Co-administration of azithromycin with ivermectin led to similar decreases in scabies and impetigo prevalence compared to ivermectin alone. The proportion of impetigo lesions containing pyogenic streptococci declined following MDA. There was a transient increase in the proportion of macrolide-resistant S. aureus strains following azithromycin MDA.

Clinical Trials Registration

clinicaltrials.gov (NCT02775617).

How strong is the relationship between scabies and acute rheumatic fever? An analysis of neighbourhood factors

AIM

Recent studies have linked scabies with acute rheumatic fever (ARF). We explored the relationship, by neighbourhood, between permethrin dispensing as an indicator of scabies prevalence and ARF cases over the same period.

METHODS

Incident cases of ARF notified to public health between September 2015 and June 2018 and the annual incidence of prescribing by neighbourhood over the same period were analysed. Evidence of an association between permethrin and ARF was obtained by carrying out Poisson regression of the rate of ARF in terms of permethrin rate at the census area unit level, with adjustment for ethnicity and socio-economic deprivation.

RESULTS

A total of 413 neighbourhoods were included. The incidence of ARF varied between 0 and 102 per 100 000 people per year (mean 4.3). In contrast, the annual incidence of dispensing of permethrin varied between 0 and 3201 per 100 000 people per year (mean 771). A strong association was observed between the two variables. In an adjusted quasi-Poisson model, permethrin-dispensing rates were strongly associated with ARF incidence, with a change from the 16th to the 84th centile associated with a 16.5-fold increase in incidence (95% confidence interval: 3.82-71.6).

CONCLUSIONS

Permethrin prescribing as an indicator of scabies is strongly associated with the incidence of ARF. Considered together with other studies, this evidence suggests that improving scabies control may reduce the burden of ARF in New Zealand.

The safety of combined triple drug therapy with ivermectin, diethylcarbamazine and albendazole in the neglected tropical diseases co-endemic setting of Fiji: A cluster randomised trial

Lymphatic filariasis has remained endemic in Fiji despite repeated mass drug administration using the well-established and safe combination of diethylcarbamazine and albendazole (DA) since 2002. In certain settings the addition of ivermectin to this combination (IDA) remains a safe strategy and is more efficacious. However, the safety has yet to be described in scabies and soil-transmitted helminth endemic settings like Fiji. Villages of Rotuma and Gau islands were randomised to either DA or IDA. Residents received weight-based treatment unblinded with standard exclusions. Participants were actively found and asked by a nurse about their health daily for the first two days and then asked to seek review for the next five days if unwell. Anyone with severe symptoms were reviewed by a doctor and any serious adverse event was reported to the Medical Monitor and Data Safety Monitoring Board. Of 3612 enrolled and eligible participants, 1216 were randomised to DA and 2396 to IDA. Age and sex in both groups were representative of the population. Over 99% (3598) of participants completed 7 days follow-up. Adverse events were reported by 600 participants (16.7%), distributed equally between treatment groups, with most graded as mild (93.2%). There were three serious adverse events, all judged not attributable to treatment by an independent medical monitor. Fatigue was the most common symptom reported by 8.5%, with headache, dizziness, nausea and arthralgia being the next four most common symptoms. Adverse events were more likely in participants with microfilaremia (43.2% versus 15.7%), but adverse event frequency was not related to the presence of scabies or soil-transmitted helminth infection. IDA has comparable safety to DA with the same frequency of adverse events experienced following community mass drug administration. The presence of co-endemic infections did not increase adverse events. IDA can be used in community programs where preventative chemotherapy is needed for control of lymphatic filariasis and other neglected tropical diseases.

Clinical presentation and risk factors of increased scabies cases in the Western region of Saudi Arabia in 2016-2018

OBJECTIVES

To describe the clinical characteristics of scabies in the Makkah province and analyze risk factors associated with the outbreak.  Methods: A cross-sectional study was conducted between June 2016 and June 2018 by collecting the data of patients reported to have infestations at King Abdulaziz Medical City, Makkah, Saudi Arabia. A comparative analysis was conducted of patients reported before and during the outbreak of scabies.  Results: Of the 352 patients identified, the range of cases was 0-24 cases per month before the months of the outbreak (March to April 2018). However, the actual number of cases reported increased 2.8 times the expected maximum in April 2018. Saudi nationals were 2.5 times more affected than non-Saudi nationals during the outbreak period compared to before the outbreak (95%CI: 1.02, 6.05, p=0.045). Symptoms involving upper arms, axillae (53.7% versus 68.7%, p=0.048), and torso (50% versus 66.4%, p=0.033) were significantly under-represented among outbreak patients. The presence of additional comorbidities was reported more frequently in patients diagnosed with scabies before versus during the outbreak months (25.8% versus 8.2%, p=0.014). Permethrin prescriptions increased (75.6% versus 41%), crotamiton prescriptions decreased (13.5% versus 48%), and the hospitalization was lower (3.8% versus 13.5%) during the outbreak.  Conclusion: The clinical presentation and risk factors of scabies change significantly with scabies outbreaks, and consequently so do the lines of treatment in Saudi Arabia. The present study highlights the importance of adopting strategies related to community infection control and prevention.

High burden and seasonal variation of paediatric scabies and pyoderma prevalence in The Gambia: A cross-sectional study

BACKGROUND

Scabies is a WHO neglected tropical disease common in children in low- and middle-income countries. Excoriation of scabies lesions can lead to secondary pyoderma infection, most commonly by Staphyloccocus aureus and Streptococcus pyogenes (group A streptococcus, GAS), with the latter linked to acute post-streptococcal glomerulonephritis (APSGN) and potentially rheumatic heart disease (RHD). There is a paucity of data on the prevalence of these skin infections and their bacterial aetiology from Africa.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional study, conducted over a four-month period that included the dry and rainy season, was conducted to determine the prevalence of common skin infections in Sukuta, a peri-urban settlement in western Gambia, in children <5 years. Swabs from pyoderma lesions were cultured for S. aureus and GAS. Of 1441 children examined, 15.9% had scabies (95% CI 12.2-20.4), 17.4% had pyoderma (95% CI 10.4-27.7) and 9.7% had fungal infections (95% CI 6.6-14.0). Scabies was significantly associated with pyoderma (aOR 2.74, 95% CI 1.61-4.67). Of 250 pyoderma swabs, 80.8% were culture-positive for S. aureus, and 50.8% for GAS. Participants examined after the first rains were significantly more likely to have pyoderma than those examined before (aRR 2.42, 95% CI 1.38-4.23), whereas no difference in scabies prevalence was seen (aRR 1.08, 95% CI 0.70-1.67). Swab positivity was not affected by the season.

CONCLUSIONS/SIGNIFICANCE

High prevalence of scabies and pyoderma were observed. Pyoderma increased significantly during the rainy season. Given the high prevalence of GAS pyoderma among children, further research on the association with RHD in West Africa is warranted.

The Relationship between Scabies and Stroke: A Population-Based Nationwide Study

BACKGROUND

Scabies is a commonly occurring infectious skin infestation that substantially impacts the quality of life, while stroke, which consists of a neurological deficit resulting from a lack of blood flow to the brain, carries sizable economic costs. The pathophysiologic mechanisms underlying both diseases involve inflammatory processes that are mediated by the immune system; however, no prior research has been conducted to explore the relationship between the two conditions.

METHODS

This population-based nationwide study utilized data from the National Health Insurance Research Database (NHIRD) of Taiwan for a total of 6628 scabies patients, who comprised a scabies group, and a randomly selected cohort of 26,509 matching patients, who served as a control group. More specifically, the medical records for the patients in both groups were checked for seven years to identify any new cases of stroke within that seven-year follow-up period. The hazard ratio (HR) of stroke for the follow-up period was then calculated using Cox proportional hazards regressions, while comorbidities and demographic characteristics were likewise analyzed.

RESULTS

During the follow-up period, 2892 patients, or 8.7%, of the overall total of 33,137 patients included in the study were newly diagnosed with a stroke. Of those newly diagnosed stroke patients, 833 were from the scabies group, and 2059 were from the control group, accounting for 12.6% and 7.8%, respectively, of the individuals in each group. With a crude hazard ratio of 1.67, the patients in the scabies group had a significantly higher risk of subsequent stroke than those in the control group, although the adjusted hazard ratio (aHR) for the scabies patients, which was determined by adjusting for covariates, was only 1.32 (95% confidence interval (CI): 1.21-1.43).

CONCLUSIONS

The results of the study indicated an elevated risk of stroke among scabies patients, an association that might be contributed to by immunopathological factors. This information could serve as a reminder to clinicians to remain alert to any indications of neurological impairment in patients previously infected with scabies.

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.

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.

Outbreak of scabies among preschool children, Accra, Ghana, 2017

Background

Scabies occurs worldwide with a prevalence between 0.3 and 46.0%. In Ghana, even though a 5.1% proportion of scabies was reported in a retrospective review of skin diseases at the Korle Bu Teaching Hospital, the nationwide prevalence of scabies is unknown. Overall, its burden is higher in tropical regions. Scabies outbreaks mostly occur among children, the elderly in nursing homes, and prison inmates. Even though primary scabies hardly results in mortalities, the pain, itch, and systemic complications from secondary bacterial infections account for about 1.5 million years lived with disabilities. We investigated a scabies outbreak among school children in Ghana to determine its magnitude, stop the outbreak, and institute preventive measures to minimize risks of future outbreaks.

Methods

The investigation was conducted between March 14 and May 17, 2017 among pupils of Presbyterian Secondary Staff Basic School in Accra. We defined a case as a school child who on clinical examination, had an intensely pruritic rash on at least one typical predilection site with or without a burrow, or positive skin scrapings on microscopy. We screened and line listed cases, performed laboratory investigations on skin scrapings and wound swaps, and conducted an environmental assessment. We performed descriptive statistics on data, and calculated attack rate ratios (ARR) at 95% confidence level.

Results

Of 823 preschool children screened, 92 were cases. Median age of cases was 4 years (range 2–7 years) and their modal age was 3 years. The overall attack rate was 11.2% (92/823). The sex specific attack rate was 11.5% for males, and 10.8% for females (ARR: 0.93; CI: 0.67–1.28). Compared with the least affected class (crèche), the nursery one class was worst affected (ARR: 5.14; CI: 3.44–7.50). On microscopy, all skin scrapings were negative for scabies. Staphylococcus aureus and Streptococcus spp. were isolated from secondarily infected scabies lesions.

Conclusions

A scabies outbreak with a propagated source occurred among preschool children. The 3-year-old pupils were most affected. It was controlled by mass treatment with benzyl benzoate and health education. Classrooms and sleeping mats were disinfected. We recommended the decongestion of classrooms and discouraged sharing of sleeping mats.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7085-6) contains supplementary material, which is available to authorized users.

Efficacy of mass drug administration with ivermectin for control of scabies and impetigo, with coadministration of azithromycin: a single-arm community intervention trial

BACKGROUND

In small community-based trials, mass drug administration of ivermectin has been shown to substantially decrease the prevalence of both scabies and secondary impetigo; however, their effect at large scale is untested. Additionally, combined mass administration of drugs for two or more neglected diseases has potential practical advantages, but efficacy of potential combinations should be confirmed.

METHODS

The azithromycin ivermectin mass drug administration (AIM) trial was a prospective, single-arm, before-and-after, community intervention study to assess the efficacy of mass drug administration of ivermectin for scabies and impetigo, with coadministration of azithromycin for trachoma. Mass drug administration was offered to the entire population of Choiseul Province, Solomon Islands, and of this population we randomly selected two sets of ten sentinel villages for monitoring, one at baseline and the other at 12 months. Participants were offered a single dose of 20 mg/kg azithromycin, using weight-based bands. Children weighing less than 12·5 kg received azithromycin oral suspension (20 mg/kg), and infants younger than 6 months received topical 1% tetracycline ointment. For ivermectin, participants were offered two doses of oral ivermectin 200 μg/kg 7-14 days apart using weight-based bands, or 5% permethrin cream 7-14 days apart if ivermectin was contraindicated. Our study had the primary outcomes of safety and feasibility of large-scale mass coadministration of oral ivermectin and azithromycin, which have been previously reported. We report here the prevalence of scabies and impetigo in residents of the ten baseline villages compared with those in the ten 12-month villages, as measured by examination of the skin, which was a secondary outcome of the trial. Further outcomes were comparison of the number of all-cause outpatient attendances at government clinics in Choiseul Province at various timepoints before and after mass drug administration. The trial was registered with the Australian and New Zealand Trials Registry (ACTRN12615001199505).

FINDINGS

During September, 2015, over 4 weeks, 26 188 people (99·3% of the estimated population of Choiseul [n=26 372] as determined at the 2009 census) were treated. At baseline, 1399 (84·2%) of 1662 people living in the first ten villages had their skin examined, of whom 261 (18·7%) had scabies and 347 (24·8%) had impetigo. At 12 months after mass drug administration, 1261 (77·6%) of 1625 people in the second set of ten villages had their skin examined, of whom 29 (2·3%) had scabies (relative reduction 88%, 95% CI 76·5-99·3) and 81 (6·4%) had impetigo (relative reduction 74%, 63·4-84·7). In the 3 months after mass drug administration, 10 614 attended outpatient clinics for any reason compared with 16 602 in the 3 months before administration (decrease of 36·1%, 95% CI 34·7-37·6), and during this period attendance for skin sores, boils, and abscesses decreased by 50·9% (95% CI 48·6-53·1).

INTERPRETATION

Ivermectin-based mass drug administration can be scaled to a population of over 25 000 with high efficacy and this level of efficacy can be achieved when mass drug administration for scabies is integrated with mass drug administration of azithromycin for trachoma. These findings will contribute to development of population-level control strategies. Further research is needed to assess durability and scalability of mass drug administration in larger, non-island populations, and to assess its effect on the severe bacterial complications of scabies.

FUNDING

International Trachoma Initiative, Murdoch Children's Research Institute, Scobie and Claire Mackinnon Trust, and the Wellcome Trust.

Observations of Pediatric Disease Prevalence from Pacific Partnership 2015

Pacific Partnership is an ongoing yearly humanitarian assistance mission to Pacific Rim countries. Although many case reports and surgical successes have been documented, few data have been published specifically about the primary care mission. This article analyzes outpatient pediatric data collected during Pacific Partnership 2015. Eleven different providers documented care delivered to children from birth through age 18 yr, inclusive. Personally de-identified data were entered into spreadsheets, sorted according to country visited, and analyzed with IBM SPSS software looking for disease frequency. One thousand eighty-seven pediatric patients were seen across Fiji, Papua New Guinea (PNG), and the Philippines (PI). Asthma was the first, second, and third most prevalent diagnosis in PNG, Fiji, and PI, with a relative proportion of the total patients seen at 5.4%, 7.2%, and 5%, respectively. In PI, 123 cases of upper respiratory infection were seen, more than four times the next most common diagnosis of normal exam. Thirty-six patients with scabies were seen in Fiji (number 1), with abdominal pain at number 3 (26 cases, 6.5%). Surprisingly, helminths were rarely seen, comprising the sixteenth and fourteenth most common diagnoses in Fiji and PI and only two cases in PNG. Future Pacific Partnership missions can plan medication stock, personnel assignment, equipment needs, and educational literature based on these data.

Prevalence of Ectoparasitic Infections and Other Dermatological Infections and Their Associated Factors among School Children in Gampaha District, Sri Lanka

Skin disorders are one of the commonest conditions among school children in developing countries. There are only a few published studies available from Sri Lanka on the prevalence of skin disorders. A community-based cross-sectional study was carried out among five government-run schools randomly selected from the district of Gampaha, Sri Lanka, during 2016-2017. A total of 41 students between 5 and 16 years of age were randomly selected from each school. Sociodemographic profile and hygienic behaviors of selected students were assessed using a pretested interviewer-administered questionnaire. Students were examined by a medical officer for the presence of different skin disorders. The chi-squared test of association and binary logistic regression were used for the identification of the significance of socioeconomic factors and hygienic practices among the study participants. A total of 205 school children participated in the study. The commonest skin disorder was pediculosis (42.0%; n=86), followed by dandruff (8.3%; n=17), fungal infections (6.8%; n=14), and scabies (1.5%; n=3). Almost one-fourth of the study participants (22.9%; n=30/131) had more than one disorder, majored by Pediculus captis infestation with dandruff. Over one-third (36.1%; n=74) were free of any skin disorders. The prevalence of skin disorders was significantly high among females (87.3%; n=110), compared to males (26.6%; n=21). Presence of long hair, higher family size, and limited number of rooms in the house were risk factors associated with the prevalence of skin disorders. The commonest skin disorder was pediculosis, while scabies and fungal infections were scarce among school children in the district of Gampaha, Sri Lanka. Implementation of health education and monitoring programs at the school level for maintaining the dermal health status of school children is recommended.

2018 WSES/SIS-E consensus conference: recommendations for the management of skin and soft-tissue infections

Skin and soft-tissue infections (SSTIs) encompass a variety of pathological conditions that involve the skin and underlying subcutaneous tissue, fascia, or muscle, ranging from simple superficial infections to severe necrotizing infections. SSTIs are a frequent clinical problem in surgical departments. In order to clarify key issues in the management of SSTIs, a task force of experts met in Bertinoro, Italy, on June 28, 2018, for a specialist multidisciplinary consensus conference under the auspices of the World Society of Emergency Surgery (WSES) and the Surgical Infection Society Europe (SIS-E). The multifaceted nature of these infections has led to a collaboration among general and emergency surgeons, intensivists, and infectious disease specialists, who have shared these clinical practice recommendations.

Feasibility and safety of mass drug coadministration with azithromycin and ivermectin for the control of neglected tropical diseases: a single-arm intervention trial

BACKGROUND

Mass drug administration has made a major contribution to the public health control of several important neglected tropical diseases. For settings with more than one endemic disease, combined mass drug administration has potential practical advantages compared with separate programmes but needs confirmation of feasibility and safety. We undertook a study of mass drug administration in the Solomon Islands for trachoma and scabies control using ivermectin and azithromycin, key drugs in the control of neglected tropical diseases worldwide.

METHODS

The entire population of Choiseul province, Solomon Islands, was eligible to participate. An azithromycin-based mass drug administration regimen was offered in line with standard recommendations for trachoma elimination (oral azithromycin or topical tetracycline). An ivermectin-based mass drug administration regimen was offered at the same time (oral ivermectin or topical permethrin), with a further dose 7-14 days later, using a modified version of a regimen demonstrated to be effective for scabies control. All participants underwent safety assessments 7-14 days later. Participants in ten randomly selected sentinel villages underwent a more detailed safety assessment. Routine health system reports of hospital or clinic admissions and deaths were also obtained to compare health outcomes in the 12 month period before and after the mass drug administration.

FINDINGS

The study enrolled 26 188 participants, 99·3% of the estimated resident population as determined at the 2009 census. Of those enrolled, 25 717 (98·2%) received the trachoma regimen and 25 819 (98·6%) received the first dose of the scabies regimen between Sept 1, and Oct 2, 2015. A second dose of the scabies regimen was received by 21 931 (83·7%) of participants. Adverse events, all mild and transient, were recorded in 571 (2·6%) of the entire study population and 58 (4·1%) of participants in the ten sentinel villages. In the 12 months before and after the mass drug administration the numbers of hospital admissions (1530 vs 1602) and deaths (73 vs 83) were similar. In the month after the mass drug administration, 84 individuals were admitted to hospital and two died, compared with a monthly median of 116 admissions (IQR 106-159) and six deaths (IQR 4-7) in the 12 months before and after the mass drug administration.

INTERPRETATION

In the largest trial so far involving coadministration of regimens based on ivermectin and azithromycin, the combination was safe and feasible in a population of more than 26 000 people. Coadministration of mass drug administration based on these two drugs opens up new potential for the control of neglected tropical diseases.

FUNDING

International Trachoma Initiative, Murdoch Children's Research Institute, Scobie and Claire Mackinnon Trust, Wellcome Trust.

Control Strategies for Scabies

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

A biological model of scabies infection dynamics and treatment informs mass drug administration strategies to increase the likelihood of elimination

Infections with Sarcoptes scabiei, or scabies, remain common in many disadvantaged populations. Mass drug administration (MDA) has been used in such settings to achieve a rapid reduction in infection and transmission, with the goal of eliminating the public health burden of scabies. While prevalence has been observed to fall substantially following such an intervention, in some instances resurgence of infection to baseline levels has occurred over several years. To explore the biology underpinning this phenomenon, we have developed a theoretical model of scabies life-cycle and transmission dynamics in a homogeneously mixing population, and simulate the impact of mass drug treatment strategies acting on egg and mite life cycle stages (ovicidal) or mites alone (non-ovicidal). In order to investigate the dynamics of the system, we first define and calculate the optimal interval between treatment doses. We calculate the probability of eradication as a function of the number of optimally-timed successive treatment doses and the number of years over which a program is run. For the non-ovicidal intervention, we first show that at least two optimally-timed doses are required to achieve eradication. We then demonstrate that while more doses over a small number of years provides the highest chance of eradication, a similar outcome can be achieved with fewer doses delivered annually over a longer period of time. For the ovicidal intervention, we find that doses should be delivered as close together as possible. This work provides a platform for further research into optimal treatment strategies which may incorporate heterogeneity of transmission, and the interplay between MDA and enhancement of continuing scabies surveillance and treatment strategies.

Skin bacterial colonizations and superinfections in immunocompetent patients with scabies

BACKGROUND

Skin bacterial colonizations and superinfections are well-known complications of scabies, in particular, in tropical and subtropical countries. However, only very rare studies on skin bacterial colonizations and superinfections have been carried out in immunocompetent patients with scabies living in Western countries.

METHODS

Eighty-nine Caucasian adult immunocompetent patients with scabies living in Milan, Italy, were subjected to bacteriologic examinations of the skin. Clinical diagnosis of scabies was confirmed in all patients by means of microscopic examinations: they were considered positive when adults or eggs or feces of Sarcoptes scabiei var. hominis were visible. In all patients, six skin swabs (three for aerobic and three for anaerobic bacteria) were taken in three different areas before the beginning of the treatment.

RESULTS

No clinical manifestations of pyoderma were observed. Bacteriologic examinations were positive in 5/89 patients (5.6%). Bacteriologic cultures were positive for Staphylococcus aureus in all five patients; in one patient, they were also positive for Escherichia coli. No growth of anaerobic bacteria was recorded.

CONCLUSIONS

According to the results of this study, skin bacterial colonizations and superinfections in immunocompetent adult patients with scabies living in Milan are uncommon. Bacteriologic examinations may therefore be considered as an unnecessary routine procedure.

Scabies in Resource-Poor Communities in Nasarawa State, Nigeria: Epidemiology, Clinical Features and Factors Associated with Infestation

Epidemiology and clinical features of scabies remain largely unknown in Nigeria’s rural communities. To fill this gap, we performed a cross-sectional study in three rural communities in north central Nigeria. A total of 500 individuals were included and examined for scabies infestation; a questionnaire was applied to collect socio-demographic and behavioral data. Scabies was diagnosed in 325 (65.0%) participants. Excoriations (68.6%), vesicles (61.8%), and papules (58.8%) were common skin lesions. Itching was the most common symptom (77.5%); 64% complained of sleep disturbances. Lymphadenopathy was identified in 48.3%. Lesions were most commonly encountered on the abdomen (35.5%), inguinal area (19.1%), and interdigital spaces (14.2%). Poverty-related variables, such as illiteracy (OR: 7.15; 95% CI: 3.71–13.95), low household income (7.25; 1.19–88.59), absence of a solid floor inside house (12.17; 2.83–52.34), and overcrowding (1.98; 1.08–2.81) were significantly associated with infestation. Individual behavior, such as sharing of beds/pillows (2.11; 1.42–3.14) and sharing of clothes (2.51; 1.57–3.99), was also highly significantly associated with scabies. Regular bathing habits (0.37; 0.24–0.56) and regular use of bathing soap (0.36; 0.21–0.53) were protective factors. Scabies is extremely common in the communities under study and is associated with considerable morbidity. The disease is intrinsically linked with extreme poverty.

Scabies, crusted (Norwegian) scabies and the diagnosis of mite sensitisation

Scabies is observed with relatively high frequency in Allergy and Dermatology clinics in developing countries where poor sanitary conditions are prevalent and increasingly in some areas of the world with increased immigrant populations. Since the immunological response to scabies mites includes the production of IgE class antibodies to Sarcoptes scabiei allergens which cross-react with Dermatophagoides major allergens Der p 1 and Der p 2, positive immediate-type skin tests to house dust mite extracts should be interpreted cautiously. Additionally, scabies should be included routinely in the differential diagnosis of itchy rashes in patients living in those areas.

Increased risk of psoriasis following scabies infection: A nationwide population-based matched-cohort study

Both scabies and psoriasis are pruritic inflammatory skin diseases. The clinical manifestations are similar and provocation of psoriasis by mite bite was reported. The association between scabies and psoriasis was not investigated before. We conducted this nationwide population-based matched-cohort study to describe if patients with a diagnosis of scabies have a different risk of developing new psoriasis. From the National Health Insurance Research Database of Taiwan, patients with scabies (n = 5137) were identified and matched for age and sex with non-scabies controls (n = 19 142). We tracked them for a 7-year period to identify the incidence of psoriasis. One hundred and ninety (0.8%) patients with newly diagnosed psoriasis were identified; 91 (1.8%) from the scabies group and 99 (0.5%) from the control group. Patients with scabies had a higher risk of subsequent psoriasis, with a crude hazard ratio of 3.45 and an adjusted hazard ratio (aHR) of 3.03 (95% confidence interval, 2.24-4.11). An increased risk for psoriasis among patients with scabies was observed (aHR, 3.03). Immunopathology involving the T-helper 17 cell-mediated inflammatory pathway may contribute to this association. Physicians may consider implementing assessments of psoriatic symptoms in patients with scabies.

Increased risk of bipolar disorder in patients with scabies: A nationwide population-based matched-cohort study

Both scabies and bipolar disorder (BD) are common and troublesome disorders. There are several similarities in both diseases: pruritus, a higher prevalence in crowded environments, and cytokine-mediated inflammatory processes in the pathophysiology. We conducted this nationwide population-based study to investigate the possible relationship between scabies and BD. Based on the National Health Insurance Research Database (NHIRD) of Taiwan, a total of 7096 patients with scabies were identified as a study group and 28,375 matched patients as a control. We tracked the patients in both groups for a 7-year period to identify those newly diagnosed with BD. The demographic characteristics and comorbidities of the patients were analyzed, and Cox proportional hazard regressions were performed to calculate the hazard ratio (HR) of BD. Of the 35,471 patients in this study, 183 (0.5%) patients with newly diagnosed BD were identified, with 58 (0.8%) from the scabies group and 125 (0.4%) from the control group. The patients with scabies had a higher risk of subsequent BD, with a crude hazard ratio of 1.86 and an adjusted hazard ratio of 1.55 (95% confidence interval: 1.12-2.09, P < 0.05). This study shows there is an increased risk for BD among patients with scabies. Immunopathology may contribute to this association.

The global burden of scabies: a cross-sectional analysis from the Global Burden of Disease Study 2015

BACKGROUND

Numerous population-based studies have documented high prevalence of scabies in overcrowded settings, particularly among children and in tropical regions. We provide an estimate of the global burden of scabies using data from the Global Burden of Disease (GBD) Study 2015.

METHODS

We identified scabies epidemiological data sources from an extensive literature search and hospital insurance data and analysed data sources with a Bayesian meta-regression modelling tool, DisMod-MR 2·1, to yield prevalence estimates. We combined prevalence estimates with a disability weight, measuring disfigurement, itch, and pain caused by scabies, to produce years lived with disability (YLDs). With an assumed zero mortality from scabies, YLDs were equivalent to disability-adjusted life-years (DALYs). We estimated DALYs for 195 countries divided into 21 world regions, in both sexes and 20 age groups, between 1990 and 2015.

FINDINGS

Scabies was responsible for 0·21% of DALYs from all conditions studied by GBD 2015 worldwide. The world regions of east Asia (age-standardised DALYs 136·32), southeast Asia (134·57), Oceania (120·34), tropical Latin America (99·94), and south Asia (69·41) had the greatest burden of DALYs from scabies. Mean percent change of DALY rate from 1990 to 2015 was less than 8% in all world regions, except North America, which had a 23·9% increase. The five individual countries with greatest scabies burden were Indonesia (age-standardised DALYs 153·86), China (138·25), Timor-Leste (136·67), Vanuatu (131·59), and Fiji (130·91). The largest standard deviations of age-standardised DALYs between the 20 age groups were observed in southeast Asia (60·1), Oceania (58·3), and east Asia (56·5), with the greatest DALY burdens in children, adolescents, and the elderly.

INTERPRETATION

The burden of scabies is greater in tropical regions, especially in children, adolescents, and elderly people. As a worldwide epidemiological assessment, GBD 2015 provides broad and frequently updated measures of scabies burden in terms of skin effects. These global data might help guide research protocols and prioritisation efforts and focus scabies treatment and control measures.

FUNDING

Bill & Melinda Gates Foundation.

The association between scabies and myasthenia gravis: A nationwide population-based cohort study

Scabies is an infectious inflammatory pruritic skin disease. Cytokine-mediated inflammatory processes contribute to the pathologic mechanism in scabies. Myasthenia gravis (MG) is also an autoimmune disease that is mediated by cytokines. The study aimed to investigate the association between scabies and myasthenia gravis. We conducted a nationwide population-based cohort study utilized data from the National Health Insurance Research Database (NHIRD) of Taiwan. Patients with scabies (n=5429) and control subjects without scabies (n=20,176) were enrolled. We tracked the subjects in both groups for a 7-year period to identify new onset MG. Cox regression analysis was performed to calculate the hazard ratio (HR) for MG. A total of 25,605 patients were enrolled in the study, including 5429 patients in the scabies group and 20,176 in the control group. There were 40 (0.7%) patients from the scabies group and 84 (0.4%) subjects from the control group who were newly diagnosed with MG during the 7-year follow-up period. The scabies patients had a significantly increased risk of MG, with an adjusted HR of 1.27 (95% confidence interval [CI] 1.01-1.89). As such, prompt diagnosis and treatment of scabies may decrease the risk of subsequent MG.

The Epidemiology of Scabies and Impetigo in Relation to Demographic and Residential Characteristics: Baseline Findings from the Skin Health Intervention Fiji Trial

Scabies and associated impetigo are under-recognized causes of morbidity in many developing countries. To strengthen the evidence base for scabies control we undertook a trial of mass treatment for scabies. We report on the occurrence and predictors of scabies and impetigo in participants at baseline. Participants were recruited in six island communities and were examined for the presence of scabies and impetigo. In addition to descriptive analyses, logistic regression models were fit to assess the association between demographic variables and outcome of interest. The study enrolled 2051 participants. Scabies prevalence was 36.4% (95% confidence interval [CI] 34.3-38.5), highest in children 5-9 years (55.7%). Impetigo prevalence was 23.4% (95% CI 21.5-25.2) highest in children aged 10-14 (39.0%). People with scabies were 2.8× more likely to have impetigo. The population attributable risk of scabies as a cause of impetigo was 36.3% and 71.0% in children aged less than five years. Households with four or more people sharing the same room were more likely to have scabies and impetigo (odds ratios [OR] 1.6, 95% CI 1.2-2.2 and OR 2.3, 95% CI 1.6-3.2 respectively) compared to households with rooms occupied by a single individual. This study confirms the high burden of scabies and impetigo in Fiji and the association between these two conditions, particularly in young children. Overcrowding, young age, and clinical distribution of lesion are important risk factors for scabies and impetigo. Further studies are needed to investigate whether the decline of endemic scabies would translate into a definite reduction of the burden of associated complications.

Increase the risk of intellectual disability in children with scabies: A nationwide population-based cohort study

Scabies is a common and distressing disease caused by the mite Sarcoptes scabiei var. hominis. Psychiatric disorder in childhood is an important disease and easily neglected. There are several similarities in scabies and psychiatric disorders in childhood (PDC). Both of them may present with pruritus. They are relatively common in patients with lower socioeconomic status and crowded environment. Furthermore, immune-mediated inflammatory processes play a role in the pathophysiology in both diseases. An association between scabies and psychiatric disorders may exist. This nationwide population-based cohort study utilized data from the National Health Insurance Research Database to investigate the relationship between scabies and PDC. A total of 2137 children with scabies were identified as the study group and 8548 age- and sex-matched children were selected as the control group. A total of 607 (5.68%) children developed PDC during the 7-year follow-up period. The overall incidences of PDC are similar but patients with scabies had a higher risk of developing intellectual disability (ID) (scabies group vs control group: 1.3% vs 0.6%, adjusted hazard ratio: 2.04 and 95% confidence interval: 1.25-3.32). The immune-mediated inflammatory processes of both diseases were reviewed and may contribute to the 104% increased risk of interleukin in patients with scabies. We suggest a more comprehensive management in treating patients with scabies or ID. Early and comprehensive treatment of scabies and other risk factors may decrease the risk of subsequent ID. When we approach patients with ID, concurrent evaluation of scabies and other risk factors may contribute to successful management.

Diagnosis and management of skin and soft-tissue infections (SSTI). A literature review and consensus statement: an update

Skin and soft-tissue infections (SSTIs) are among the most common bacterial infections, posing considerable diagnostic and therapeutic challenges. Fourteen members of the Italian Society of Infectious Diseases, after a careful review of the most recent literature using Medline database and their own clinical experience, updated a previous paper published in 2011 by preparing a draught manuscript of the statements. The manuscript was successively reviewed by all members and ultimately re-formulated the present manuscript during a full day consensus meeting. The microbiological and clinical aspects together with diagnostic features were considered for necrotizing and not necrotizing SSTIs in the light of the most recent guidelines and evidences published in the last five years. The antimicrobial therapy was considered as well - both empirical and targeted to methicillin-resistant Staphylococcus aureus and/or other pathogens, also taking into account the epidemiological and bacterial resistance data and the availability of new antibacterial agents.

Incidental mosquitocidal effect of an ivermectin mass drug administration on Anopheles farauti conducted for scabies control in the Solomon Islands

Background

The Solomon Islands is targeting elimination of malaria by 2030. The dominant vector is the predominantly exophagic, exophilic Anopheles farauti sensu strictu. This biting behaviour limits the efficacy of conventional vector control tools and highlights the need for new strategies. When administered to humans ivermectin has been shown to have a mosquitocidal effect. Mass drug administration (MDA) with ivermectin is an emerging strategy in the control of scabies. In this study we explored any incidental effect of ivermectin MDA conducted for scabies control on mosquitoes.

Methods

MDA for scabies was conducted in three villages. We performed human landing catches and measured 5-day mortality amongst Anopheles mosquitoes caught before and after MDA. Cox regression was used to calculate hazard ratios (HR) for mortality between mosquitoes caught before and after MDA.

Results

There was a significant increase in 5-day mortality in anopheline mosquitoes caught post-MDA which was highest on the day of MDA itself (HR 4.2 95% CI 1.8 to 10.1, p=0.001) and the following day (HR 4.4 95% CI 1.8 to 10.8, p=0.002) compared to mosquitoes caught before MDA.

Conclusions

This study shows a possible mosquitocidal effect of ivermectin MDA conducted for scabies control. Studies with a larger sample size with clinical as well as entomological outcomes should be conducted in this population.

Social mixing in Fiji: Who-eats-with-whom contact patterns and the implications of age and ethnic heterogeneity for disease dynamics in the Pacific Islands

Empirical data on contact patterns can inform dynamic models of infectious disease transmission. Such information has not been widely reported from Pacific islands, nor strongly multi-ethnic settings, and few attempts have been made to quantify contact patterns relevant for the spread of gastrointestinal infections. As part of enteric fever investigations, we conducted a cross-sectional survey of the general public in Fiji, finding that within the 9,650 mealtime contacts reported by 1,814 participants, there was strong like-with-like mixing by age and ethnicity, with higher contact rates amongst iTaukei than non-iTaukei Fijians. Extra-domiciliary lunchtime contacts follow these mixing patterns, indicating the overall data do not simply reflect household structures. Inter-ethnic mixing was most common amongst school-age children. Serological responses indicative of recent Salmonella Typhi infection were found to be associated, after adjusting for age, with increased contact rates between meal-sharing iTaukei, with no association observed for other contact groups. Animal ownership and travel within the geographical division were common. These are novel data that identify ethnicity as an important social mixing variable, and use retrospective mealtime contacts as a socially acceptable metric of relevance to enteric, contact and respiratory diseases that can be collected in a single visit to participants. Application of these data to other island settings will enable communicable disease models to incorporate locally relevant mixing patterns in parameterisation.

Community seroprevalence survey for yaws and trachoma in the Western Division of Fiji

BACKGROUND

Both yaws and trachoma are endemic in several countries in the Pacific. In co-endemic countries there may be potential synergies between both control programmes.

METHODS

We undertook a cluster randomised trachoma and yaws seroprevalence survey of children in the Western Division of Fiji. Children were examined for skin lesions consistent with active yaws. A dried blood spot was collected which was tested using the Treponema pallidum particle agglutination (TPPA) test and an ELISA to detect antibodies against Pgp3.

RESULTS

A total of 607 children from 305 households across 23 villages were recruited into the survey. On skin examination, no child had clinical evidence of yaws, and the TPPA assay was negative in all children (0%, 95% CI 0.0-0.6). The seroprevalence of Pgp3 antibodies was 20.9% (95% CI 17.8-24.6%).

DISCUSSION

In this study there was neither clinical nor serological evidence that transmission of yaws was ongoing. The Pgp3 seroprevalence pattern was consistent with either low level transmission of ocular Chlamydia trachomatis or exposure to C. trachomatis in the birth canal which is consistent with a survey conducted in the same region in 2013. These data suggest neither yaws nor ocular chlamydia infection are a significant public health problem in the Western Division of Fiji.

Adherence to secondary antibiotic prophylaxis for patients with rheumatic heart disease diagnosed through screening in Fiji

OBJECTIVES

Echocardiographic screening for rheumatic heart disease (RHD) can detect subclinical cases; however, adequate adherence to secondary antibiotic prophylaxis (SAP) is required to alter disease outcomes. We aimed to investigate the adherence to SAP among young people with RHD diagnosed through echocardiographic screening in Fiji and to investigate factors associated with adherence.

METHODS

Patients diagnosed with RHD through echocardiographic screening in Fiji from 2006 to 2014 were included. Dates of benzathine penicillin G injections were collected from 76 health clinics nationally from December 2011 to December 2014. Adherence was measured using the proportion of days covered (PDC). Multivariate logistic regression analysis was used to identify characteristics associated with any adherence (≥1 injection received) and adequate adherence (PDC ≥0.80).

RESULTS

Of 494 patients, 268 (54%) were female and the median age was 14 years. Overall, 203 (41%) had no injections recorded and just 33 (7%) had adequate adherence. Multivariate logistic regression showed increasing age (OR 0.93 per year, 95% CI 0.87-0.99) and time since diagnosis ≥1.5 years (OR 0.53, 95% CI 0.37-0.79) to be inversely associated with any adherence. Non-iTaukei ethnicity (OR 2.58, 95%CI 1.04-6.33) and urban residence (OR 3.36, 95% CI 1.54-7.36) were associated with adequate adherence, whereas time since diagnosis ≥1.5 years (OR 0.38, 95%CI 0.17-0.83) was inversely associated with adequate adherence.

CONCLUSIONS

Adherence to SAP after screening in Fiji is currently inadequate for individual patient protection or population disease control. Secondary prevention should be strengthened before further screening can be justified.

Protocol for the systematic review of the prevention, treatment and public health management of impetigo, scabies and fungal skin infections in resource-limited settings

BACKGROUND

Impetigo, scabies, and fungal skin infections disproportionately affect populations in resource-limited settings. Evidence for standard treatment of skin infections predominantly stem from hospital-based studies in high-income countries. The evidence for treatment in resource-limited settings is less clear, as studies in these populations may lack randomisation and control groups for cultural, ethical or economic reasons. Likewise, a synthesis of the evidence for public health control within endemic populations is also lacking. We propose a systematic review of the evidence for the prevention, treatment and public health management of skin infections in resource-limited settings, to inform the development of guidelines for the standardised and streamlined clinical and public health management of skin infections in endemic populations.

METHODS

The protocol has been designed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. All trial designs and analytical observational study designs will be eligible for inclusion. A systematic search of the peer-reviewed literature will include PubMed, Excertpa Medica and Global Health. Grey literature databases will also be systematically searched, and clinical trials registries scanned for future relevant studies. The primary outcome of interest will be the clinical cure or decrease in prevalence of impetigo, scabies, crusted scabies, tinea capitis, tinea corporis or tinea unguium. Two independent reviewers will perform eligibility assessment and data extraction using standardised electronic forms. Risk of bias assessment will be undertaken by two independent reviewers according to the Cochrane Risk of Bias tool. Data will be tabulated and narratively synthesised. We expect there will be insufficient data to conduct meta-analysis. The final body of evidence will be reported against the Grades of Recommendation, Assessment, Development and Evaluation grading system.

DISCUSSION

The evidence derived from the systematic review will be used to inform the development of guidelines for the management of skin infections in resource-limited settings. The evidence derived will be intended for use by clinicians, public health practitioners and policy makers in the treatment of skin infections and the development of skin infection control programmes. The review will identify any gaps in the current evidence to provide direction for future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015029453.

The Prevalence of Scabies and Impetigo in the Solomon Islands: A Population-Based Survey

Background

Scabies and impetigo are common, important and treatable skin conditions. Reports from several Pacific island countries show extremely high prevalence of these two conditions, but for many countries, including the Solomon Islands, there is a paucity of epidemiological data.

Methodology

Ten rural villages in the Western Province of the Solomon Islands were included in the study, chosen so that data collection could be integrated with an existing project investigating clinical and serological markers of yaws. All residents were eligible to participate, and 1908 people were enrolled. Participants were interviewed and examined by a paediatric registrar, who recorded relevant demographic information, and made a clinical diagnosis of scabies and/or impetigo, severity and distribution.

Principal Findings

The total unweighted prevalence of scabies was 19.2% (95% confidence interval [CI] 17.5–21.0), and age and gender weighted prevalence 19.2% (95%CI 16.7–21.9). The adult prevalence of scabies was 10.4% (95%CI 8.2–13.2), and the highest prevalence was found in infants < 1 year of age (34.1%, adjusted odds ratio [AOR] compared with adults: 3.6, 95%CI 2.2–6.0) and children aged 1–4 years (25.7%, AOR 2.6, 95%CI 1.7–3.9). Scabies affected two or more body regions in 80.9% of participants, and 4.4% of scabies cases were classified as severe. The total unweighted prevalence of active impetigo was 32.7% (95%CI 30.6–34.8), and age and gender weighted prevalence 26.7% (95%CI 24.2–29.5). The highest prevalence was found in children aged 1–4 years (42.6%, AOR compared with adults: 4.1, 95%CI 2.9–5.8). Scabies infestation was associated with active impetigo infection (AOR 2.0, 95%CI 1.6–2.6); with 41.1% of active impetigo cases also having scabies.

Conclusions and Significance

Scabies and impetigo are very common in the rural Western Province of the Solomon Islands. Scabies infestation is strongly associated with impetigo. Community control strategies for scabies may reduce the burden of both conditions and their downstream complications.

Scabies, a parasitic infection, and impetigo, a superficial bacterial infection, are treatable skin conditions found most commonly in resource-limited settings. Scabies is strongly associated with impetigo. Complications of impetigo include sepsis and invasive infections, and post-infective complications such as acute post streptococcal glomerulonephritis and acute rheumatic fever. Good data on scabies and impetigo prevalence are lacking for most countries, but existing evidence suggests the Pacific region has among the highest prevalence of these conditions in the world. Our study aimed to establish the prevalence of scabies and impetigo in the Western Province of the Solomon Islands, a South Pacific nation made up of over 900 islands and over 500,000 inhabitants. We assessed over 1900 people of all ages, and found a very high burden of skin infections, with scabies affecting one in five people, and active impetigo in one in three. Infants and children were affected more than adults. Scabies infestation was strongly associated with impetigo, supporting the hypothesis that community control strategies for scabies may be successful in reducing the burden of impetigo and its sequelae.

Impetigo and scabies - Disease burden and modern treatment strategies

Impetigo and scabies both present different challenges in resource-limited compared with industrialised settings. Severe complications of these skin infections are common in resource-limited settings, where the burden of disease is highest. The microbiology, risk factors for disease, diagnostic approaches and availability and suitability of therapies also vary according to setting. Taking this into account we aim to summarise recent data on the epidemiology of impetigo and scabies and describe the current evidence around approaches to individual and community based treatment.

The Importance of Scabies Coinfection in the Treatment Considerations for Impetigo

BACKGROUND

Skin infections account for a high disease burden in indigenous children living in northern Australia. Although the relationship between impetigo and scabies is recognized, the prevalence of scabies in children with impetigo is not well reported. We report the prevalence, demographics and treatment success outcomes of impetigo and scabies coinfection in indigenous children who were participants in a randomized controlled trial of impetigo treatment conducted in remote communities of the Northern Territory, Australia.

METHODS

Of 1715 screening episodes for impetigo, 508 children were randomized to receive intramuscular benzathine benzylpenicillin (BPG), twice daily co-trimoxazole (SXT) for 3 days (4 mg/kg trimethoprim plus 20 mg/kg sulfamethoxazole per dose) or once daily SXT for 5 days (8 mg/kg trimethoprim plus 40 mg/kg sulfamethoxazole per dose). A clinical diagnosis of scabies; tinea of the skin, scalp or nail; and head lice was made on all children. Scabies presence was not confirmed using diagnostic scrapings. In a post-hoc analysis, we determined whether coinfection with scabies had an impact on treatment success for impetigo.

RESULTS

Of children randomized to receive treatment for impetigo, 84 of 508 (16.5%) had scabies. The presence of scabies ranged from 14.3% to 20.0% in the 3 treatment groups. Treatment success for impetigo with and without scabies coinfection, independent of the treatment groups, was 75.9% and 86.6%, respectively, absolute difference 10.7% [95% confidence interval (CI): +1% to +21%]. Treatment success for impetigo with and without scabies coinfection in the BPG group was 69.6% and 88.0%, respectively, absolute difference 18.4% (95% CI: -1% to +38%). In the pooled SXT groups, the treatment success for impetigo with and without scabies coinfection was 78.6% and 86.0%, respectively, with absolute difference 7.4% (95% CI: -4% to +18%). Treatment success in the pooled SXT group with scabies (78.6%) was higher than in the BPG group (69.6%) with scabies, absolute difference 9.0% (95% CI: +0.1% to +18%). Prediction of treatment success for impetigo is dependent on the presence or absence of scabies and for scabies coinfected impetigo it was higher in the group treated with SXT.

CONCLUSIONS

The burden of scabies in an impetigo trial for Indigenous children was high. Treatment success for scabies coinfection was lower than for impetigo overall, with a higher success seen in the SXT group than the BPG group.

Staphylococcus aureus-Associated Skin and Soft Tissue Infections: Anatomical Localization, Epidemiology, Therapy and Potential Prophylaxis

Skin and soft tissue infections (SSTIs) are among the most common infections worldwide. They range in severity from minor, self-limiting, superficial infections to life-threatening diseases requiring all the resources of modern medicine. Community (CA) and healthcare (HA) acquired SSTIs are most commonly caused by Staphylococcus aureus . They have variable presentations ranging from impetigo and folliculitis to surgical site infections (SSIs). Superficial SSTIs may lead to even more invasive infections such as bacteraemia and osteomyelitis. Here we describe the anatomical localization of the different SSTI associated with S. aureus, the virulence factors known to play a role in these infections, and their current epidemiology. Current prevention and treatment strategies are also discussed. Global epidemiological data show increasing incidence and severity of SSTIs in association with methicillin-resistant S. aureus strains (MRSA). CA-SSTIs are usually less morbid compared to other invasive infections caused by S. aureus, but they have become the most prevalent, requiring a great number of medical interventions, extensive antibiotic use, and therefore a high cost burden. Recurrence of SSTIs is common after initial successful treatment, and decolonization strategies have not been effective in reducing recurrence. Furthermore, decolonization approaches may be contributing to the selection and maintenance of multi-drug resistant strains. Clinical studies from the early 1900s and novel autovaccination approaches suggest an alternative strategy with potential effectiveness: using vaccines to control S. aureus cutaneous infections.

Mass Drug Administration for Scabies Control in a Population with Endemic Disease

BACKGROUND

Scabies is an underrecognized cause of illness in many developing countries. It is associated with impetigo, which can lead to serious systemic complications. We conducted a trial of mass drug administration for scabies control in Fiji.

METHODS

We randomly assigned three island communities to one of three different interventions for scabies control: standard care involving the administration of permethrin to affected persons and their contacts (standard-care group), mass administration of permethrin (permethrin group), or mass administration of ivermectin (ivermectin group). The primary outcome was the change in the prevalence of scabies and of impetigo from baseline to 12 months.

RESULTS

A total of 2051 participants were enrolled; 803 were in the standard-care group, 532 in the permethrin group, and 716 in the ivermectin group. From baseline to 12 months, the prevalence of scabies declined significantly in all groups, with the greatest reduction seen in the ivermectin group. The prevalence declined from 36.6% to 18.8% in the standard-care group (relative reduction in prevalence, 49%; 95% confidence interval [CI], 37 to 60), from 41.7% to 15.8% in the permethrin group (relative reduction, 62%; 95% CI, 49 to 75), and from 32.1% to 1.9% in the ivermectin group (relative reduction, 94%; 95% CI, 83 to 100). The prevalence of impetigo also declined in all groups, with the greatest reduction seen in the ivermectin group. The prevalence declined from 21.4% to 14.6% in the standard-care group (relative reduction, 32%; 95% CI, 14 to 50), from 24.6% to 11.4% in the permethrin group (relative reduction, 54%; 95% CI, 35 to 73), and from 24.6% to 8.0% in the ivermectin group (relative reduction, 67%; 95% CI, 52 to 83). Adverse events were mild and were reported more frequently in the ivermectin group than in the permethrin group (15.6% vs. 6.8%).

CONCLUSIONS

Mass drug administration, particularly the administration of ivermectin, was efficacious for the control of scabies and impetigo. (Funded by the Australian National Health and Medical Research Council; Australian New Zealand Clinical Trials Registry number, ACTRN12613000474752.).

Long Term Control of Scabies Fifteen Years after an Intensive Treatment Programme

INTRODUCTION

Scabies is a major public health problem in the Pacific and is associated with an increased risk of bacterial skin infections, glomerulonephritis and rheumatic fever. Mass drug administration with ivermectin is a promising strategy for the control of scabies. Mass treatment with ivermectin followed by active case finding was conducted in five communities in the Solomon Islands between 1997 and 2000 and resulted in a significant reduction in the prevalence of both scabies and bacterial skin infections.

METHODS

We conducted a prospective follow-up study of the communities where the original scabies control programme had been undertaken. All residents underwent a standardised examination for the detection of scabies and impetigo.

RESULTS

Three hundred and thirty eight residents were examined, representing 69% of the total population of the five communities. Only 1 case of scabies was found, in an adult who had recently returned from the mainland. The prevalence of active impetigo was 8.8% overall and 12.4% in children aged 12 years or less.

DISCUSSION

We found an extremely low prevalence of scabies 15 years after the cessation of a scabies control programme. The prevalence of impetigo had also declined further since the end of the control programme. Our results suggest that a combination of mass treatment with ivermectin and intensive active case finding may result in long term control of scabies. Larger scale studies and integration with other neglected tropical disease control programmes should be priorities for scabies control efforts.

The Potential for a Blood Test for Scabies

Background

Scabies afflicts millions of people worldwide, but it is very difficult to diagnose by the usual skin scrape test, and a presumptive diagnosis is often made based on clinical signs such as rash and intense itch. A sensitive and specific blood test to detect scabies would allow a physician to quickly make a correct diagnosis.

Objective

Our objective was to profile the mite-specific antibodies present in the sera of patients with ordinary scabies.

Methods

Sera of 91 patients were screened for Ig, IgD, IgE, IgG and IgM antibodies to S. scabiei, as well as to the house dust mites Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei.

Results

45%, 27% and 2.2% of the patients had measurable amounts of mixed Ig, IgG and IgE that recognized scabies mite antigens. However, 73.6% of the scabies patients had serum IgM that recognized scabies proteins, and all except two of them also had IgM that recognized all of the three species of dust mites. No patient had serum antibody exclusively reactive to scabies mite antigens.

Conclusions

Co-sensitization or cross-reactivity between antigens from scabies and house dust mites confounds developing a blood test for scabies.

Scabies, caused by the mite S. scabiei that burrows in the skin of humans, is a contagious skin disease that affects millions of people worldwide. It is a significant public health burden in economically disadvantaged populations, and outbreaks are common in nursing homes, daycare facilities, schools and workplaces in developed countries. It causes significant morbidity, and in chronic cases, associated bacterial infections can lead to renal and cardiac diseases. Scabies is very difficult to diagnose by the usual skin scrape test, and a presumptive diagnosis is often made based on clinical signs such as rash and itch that can mimic other skin disease. A sensitive and specific blood test to detect scabies-specific antibodies would allow a physician to quickly make a correct diagnosis. Our manuscript reports the antibody isotype profiles of the sera of two groups of patients with ordinary scabies (17 from the US and 74 from Brazil) and concludes that such a blood test should be based on circulating IgM type antibodies that do not also recognize antigens of the related and ubiquitous house dust mites. Both are important considerations for research for developing a blood test for the diagnosis of scabies.

Hierarchy and molecular properties of house dust mite allergens

The allergenic load of house dust mite allergy is largely constituted by a few proteins with a hierarchical pattern of allergenicity. The serodominant specificities are the group 1&2 and the group 23 faecal allergens. The collective IgE binding to the group 1&2 allergens can measure unequivocal HDM sensitisation better than HDM extracts although discrepancies have been found in regions with complex acarofauna suggesting a need to investigate the specificity with allergen components. The group 4, 5, 7&21 allergens that each induce responses in about 40% of subjects are mid-tier allergens accounting for most of the remaining IgE binding. Their titres are proportional to the concomitant responses to Der p1&2. Group 2 allergen variants have different antibody binding. Body proteins only occasionally induce sensitisation although a higher prevalence of binding by atopic dermatitis patients provides a new avenue of research. A broad spectrum of IgE binding has been associated with diverse symptoms but not with the severity of asthma which is associated with low IgG antibody. Some allergens such as the group 14 large lipid binding proteins and the recently described proteins Der f 24-33, need further investigation but with the cognoscence that other denominated allergens have been found to be minor sensitisers by comparative quantitative analyses. Scabies is a confounder for diagnosis with extracts, inducing cross-reactive antibodies with Der p 4&20 as is seafood allergy with cross reactivity to Der p 10 a minor HDM allergen. The HDM genome sequence can now be used to verify allelic and paralogous variations.