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.

Hookworm-related cutaneous larva migrans in patients living in an endemic community in Brazil: immunological patterns before and after ivermectin treatmen.

Hookworm-related cutaneous larva migrans (Hr-CLM) is caused by animal hookworm larvae migrating in the human epidermis where they elicit an inflammatory response. This study describes the immunological profile in Hr-CLM patients. In 77 Hr-CLM patients from Manaus, Brazil, peripheral eosinophils were counted, and serum concentrations of total immunoglobulin E (IgE) and selected cytokines were determined by ELISA before and after treatment with ivermectin. Controls included patients' household members (endemic controls), non-endemic Brazilian and Japanese individuals. Eosinophil counts and total IgE in Hr-CLM patients were higher than in controls and correlated with disease severity. Concentrations of interleukin (IL)-4, IL-5, IL-6, and IL-10 were higher in Hr-CLM patients than in endemic controls (p < 0.001) while no differences were detected for interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-1ß, IL-2, or transforming growth factor (TGF)-ß. Following ivermectin treatment, numbers of eosinophils and concentrations of IL-4, IL-5, and IL-10 decreased whereas IgE, IFN-γ, and TGF-ß concentrations increased. The IL-5/IFN-γ ratio declined from 5.9 (interquartile range [IQR] 0.8-31.6) before to 0.1 (IQR 0.05-0.2; p = 0.001) after treatment. Thus, although an impact of other infections on the immune parameters determined cannot be excluded, Hr-CLM in endemic areas is associated with eosinophilia and elevated cytokine levels, particularly of IL-5 and IL-10, which decrease following ivermectin treatment.

Tungiasis (sand flea disease): a parasitic disease with particular challenges for public health.

Tungiasis (sand flea disease) is caused by the penetration of females of Tunga penetrans into the skin of the feet. Within 2 weeks of penetration the burrowed flea increases its volume by a factor of 2,000. This is paralleled by intense inflammation of the surrounding tissue. Acute and chronic inflammation leads to the development of painful and debilitating clinical pathology. This results in impaired physical fitness and mobility. The social implications of tungiasis-associated morbidity are multifold. Children with tungiasis are teased and ridiculed, adults feel ashamed and stigmatized. There is anecdotal evidence that tungiasis negatively affects educational achievements. Impaired mobility and physical fitness will have a negative impact on household economics. Sand flea disease is common in resource-poor communities in South America and in sub-Saharan Africa with prevalence in the general population of up to 60%. In East Africa, it has re-emerged in epidemic dimensions in recent years. Hitherto, no effective drug treatment has been at hand. Traditional treatment, i.e., the manipulation of burrowed sand fleas with blunt and inappropriate instruments may facilitate the transmission of blood-derived pathogens. Prevention is feasible through regular application of a repellent based on coconut oil. Owing to its strong association with poverty, sand flea disease would be an excellent starting point for a community-based fight against rural poverty.

Investigation of a scabies outbreak in a kindergarten in Constance, Germany.

In industrialized countries, scabies occurs sporadically or in the form of protracted epidemics, typically in nursing homes for elderly people. Outbreaks of scabies in a kindergarten are very rare. The main goal of our study was to investigate an outbreak of scabies in a kindergarten and to identify risk factors for the infestation with the ectoparasitosis. We investigated an outbreak of scabies in a kindergarten in the City of Constance, southern Germany, with a particular pedagogical concept. Risk factors indicating a transmission of Sarcoptes mites through body contact or via fomites were assessed using questionnaires and by following the daily routine in the kindergarten. A total of 16 cases were identified. The attack rate was significantly higher in nursery teachers (risk ratio 42.1) compared to children (risk ratio 10.5). In all cases, scabies had developed rather recently, with minimal clinical manifestations. In nursery teachers, the probability of scabies was 4.4 times higher in those teachers who hugged children regularly. Children who preferably played with their own soft toys had a lower probability of developing scabies [risk ratio 0.14, 95 % confidence interval (CI) 0.05-0.42; p = 0.04]. It seems conceivable that the particular pedagogical concept of the kindergarten favored the spread of Sarcoptes mites. We were unable to show whether transmission had preferably occurred through body contact or via fomites.

Human papillomavirus genotype distribution and risk factors for infection in women from a small municipality in north east Brazil.

In order to assess the prevalence of human papillomavirus (HPV) infection, the HPV genotypes and factors associated with infection, we conducted a population-based survey in a small municipality in north east Brazil among women aged between 12 and 49 years. A questionnaire regarding socioeconomic variables, reproductive life and sexual behaviour was used, and women were examined gynaecologically, followed by collection of vaginal lavage with saline solution for HPV DNA determination. HPV DNA was detected by the Digene(®) SHARP Signal(TM)-System, and further genotyped by INNO-LiPA Genotyping System(®). Of 579 women, HPV infection was present in 68 (prevalence: 11.7%; 95% CI: 9.3-14.7). The most common HPV types were 16, 31 and 74, each accounting for 14.7% of infections. Of all HPV-positive women, 35.3% showed multiple HPV genotypes. Variables independently associated with HPV infection were: ≥3 partners in life (adjusted OR [aOR]: 3.06; 95% CI: 1.68-5.60) and the use of oral contraception in the last 12 months (aOR: 2.39; 95% CI: 1.33-4.30). Previous participation in a cervical cancer screening programme was protective (aOR: 0.28; 95% CI: 0.13-0.60). HPV infection is common among women from rural Brazil, and HPV genotypes identified indicate that immunization could be an important preventive measure in this population.

Pediculosis capitis: new insights into epidemiology, diagnosis and treatment.

Pediculosis capitis is a ubiquitous parasitic skin disease caused by Pediculus humanus capitis. Head lice are highly specialised parasites which can propagate only on human scalp and hair. Transmission occurs by direct head-to-head contact. Head lice are vectors of important bacterial pathogens. Pediculosis capitis usually occurs in small epidemics in play groups, kindergartens and schools. Population-based studies in European countries show highly diverging prevalences, ranging from 1% to 20%. The diagnosis of head lice infestation is made through the visual inspection of hair and scalp or dry/wet combing. The optimal method for the diagnosis of active head lice infestation is dry/wet combing. Topical application of a pediculicide is the most common treatment. Compounds with a neurotoxic mode of action are widely used but are becoming less effective due to resistant parasite populations. Besides, their use is restricted by safety concerns. Dimeticones, silicone oils with a low surface tension and the propensity to perfectly coat surfaces, have a purely physical mode of action. This group of compounds is highly effective and safe, and there is no risk that head lice become resistant. The control of epidemics requires active contact tracing and synchronised treatment with an effective and safe pediculicide.

Mini review: Hookworm-related cutaneous larva migrans.

Hookworm-related cutaneous larva migrans (HrCLM) is a parasitic skin disease caused by the migration of animal hookworm larvae in the epidermis. Since these larvae cannot penetrate the basal membrane of human skin, they remain confined to the epidermis and are unable to develop and complete their lifecycle. By consequence, HrCLM is a self-limiting disease. However, if not treated promptly, the skin pathology may persist for months. HrCLM is endemic in many resource-poor communities in the developing world. In high-income countries, HrCLM occurs sporadically or in the form of small epidemics. Travelers account for the great majority of cases seen by health-care professionals in high-income countries. Transmission occurs when naked skin comes into contact with contaminated soil. Exposure may also occur indoors. Exceptionally, larvae may be transmitted through fomites. The first clinical sign is a small reddish papule. Thereafter, the characteristic serpiginous, slightly elevated, erythematous track becomes visible. Itching becomes more and more intense. Excoriations induced by scratching facilitate bacterial superinfection of the lesion. The diagnosis is essentially clinical. It is supported by a recent travel history and the possibility of exposure. The drug of choice is ivermectin in a single dose (200 µg per kg bodyweight). Repeated treatments with albendazole (400 mg daily) are a good alternative in countries where ivermectin is not available.

Pair decay width of the Hoyle state and its role for stellar carbon production.

The pair decay width of the first excited 0+ state in 12C (the Hoyle state) is deduced from a novel analysis of the world data on inelastic electron scattering covering a wide momentum transfer range, thereby resolving previous discrepancies. The extracted value Γπ=(62.3±2.0) µeV is independently confirmed by new data at low momentum transfers measured at the S-DALINAC and reduces the uncertainty of the literature values by more than a factor of 3. A precise knowledge of Γπ is mandatory for quantitative studies of some key issues in the modeling of supernovae and of asymptotic giant branch stars, the most likely site of the slow-neutron nucleosynthesis process.

Occurrence of the off-host life stages of Tunga penetrans (Siphonaptera) in various environments in Brazil.

To explore the local transmission dynamics of Tunga penetrans in brazil, 134 soil samples from various environments were collected in three different endemic regions of the country and checked for the presence of the flea's larvae, pupae and adults. the samples, which came from an urban slum in the north-east, a village of xavante indians in the central-west and a community of yanomami indians living in traditional longhouses (malocas) in the north, were categorized as indoor, outdoor or indoor-outdoor (the latter representing samples collected in the malocas). The proportion of samples found positive for T. penetrans was lowest in the slum (9.3%) and highest in the Yanomami village (32.0%; P=0.01). Soil samples collected below bedsteads or hammocks or from the indoor resting places of dogs were significantly more likely to be positive than the indoor samples collected at other sites (65.0% v. 35.0%; P=0.02). There was no evidence indicating that the presence of T. penetrans in a soil sample was markedly affected by soil temperature, air temperature or air humidity. As no life stages of T. penetrans were found in any outdoor sample, it seems likely that, in resource-poor settings in Brazil, most transmission of T. penetrans occurs indoors. Control measures against the off-host life stages of T. penetrans should therefore be targeted at particular indoor micro-environments.

A simple method for rapid community assessment of tungiasis.

OBJECTIVE: To evaluate a rapid assessment method to estimate the overall prevalence of tungiasis and severity of disease in endemic communities. METHODS: We analysed data from 10 population-based surveys on tungiasis, performed in five endemic communities in Brazil and Nigeria between 2001 and 2008. To assess the association between occurrence of tungiasis on six defined topographic areas of the feet and the true prevalence/prevalence of severe disease, linear regression analyses were performed. Estimated prevalences were calculated for each of the 10 surveys and compared to true prevalences. We then selected the most useful topographic localization to define a rapid assessment method, based on the strength of association and operational aspects. RESULTS: In total, 7121 individuals of the five communities were examined. Prevalence of tungiasis varied between 21.1% and 54.4%. The presence of periungual lesions on the toes was identified as the most useful rapid assessment to estimate the prevalence of tungiasis (absolute errors: -4% to +3.6%; R(2 )=96%; P < 0.0001). Prevalence of severe tungiasis (>20 lesions) was also estimated by the method (absolute errors: -3.1% to +2.5%; R(2 )=76%; P = 0.001). CONCLUSION: Prevalence of tungiasis and prevalence of severe disease can be reliably estimated in communities with distinct cultural and geographical characteristics, by applying a simple and rapid epidemiological method. This approach will help to detect high-risk communities and to monitor control measures aimed at the reduction of tungiasis.

Masses and charge radii of 17-22Ne and the two-proton-halo candidate 17Ne.

High-precision mass and charge radius measurements on ;{17-22}Ne, including the proton-halo candidate 17Ne, have been performed with Penning trap mass spectrometry and collinear laser spectroscopy. The 17Ne mass uncertainty is improved by factor 50, and the charge radii of ;{17-19}Ne are determined for the first time. The fermionic molecular dynamics model explains the pronounced changes in the ground-state structure. It attributes the large charge radius of 17Ne to an extended proton configuration with an s;{2} component of about 40%. In 18Ne the smaller radius is due to a significantly smaller s;{2} component. The radii increase again for ;{19-22}Ne due to cluster admixtures.

[Pediculosis capita in childhood: epidemiological and socio-medical results from screening of school beginners]. / Pediculosis capitis im Kindesalter: epidemiologische und sozialmedizinische Erkenntnisse einer Reihenuntersuchung von Schulanfängern.

Although pediculosis capitis is the most frequent parasitosis in childhood, reliable data on its epidemiology and morbidity are scarce. In Germany population-based data do not exist. During the routine medical examination of 5-6-year-old pre-school children in Braunschweig city (n=1 890) the children were also examined for the presence of head lice and head lice-associated pathology. Visual inspection of five predilection sites was used to diagnose head lice infestation. Knowledge of careers on head lice infestation and disease perception were analysed using a standardised questionnaire. Socio-demographic variables of the households to which the children belonged were correlated to current or historical head lice infestation. Head lice infestation was diagnosed in 14 out of the 1 890 children (0.7%). Considering the low sensitivity of visual inspection the true prevalence should be higher by a factor 3 to 4. In addition, 5.6% of the children examined had suffered from a head lice infestation in the previous 12 months. This results in an incidence of 598 cases per 10,000 children aged 5 to 6 years per year. Households with a low educational level of the parents and without a background of migration were significantly more often affected by pediculosis capitis during the previous 12 months. The analysis of the questionnaires showed a rather low level of knowledge about pediculosis capitis, a tendency towards polypragmatic therapeutic approaches and partially aberrant reactions such as hysteria. The knowledge about pediculosis capitis was significantly lower in parents with a low educational level. Our study provides for the first time reliable data on the prevalence, incidence and disease perception of head lice infestation as well as concerning the knowledge parents have about this parasitic skin disease.

[Tungiasis and myiasis]. / Tungiasis und Myiasis.

Tungiasis (sand flea disease) and myiasis are ectoparasitoses, in which the infectious agent resides temporarily in the skin (myiasis) or dies and is eventually eliminated (tungiasis). Both diseases are zoonoses. Whereas in myiasis humans are only an accidental host, in tungiasis the prevalence in humans is similar to that of their domestic animals. In travellers returning from the tropics tungiasis and myiasis are not rare, however they are frequently misdiagnosed. The diagnosis of both infestations is made clinically, and laboratory investigations are not helpful. In tungiasis the clinical picture depends on the stage of the disease. A heavy local inflammation and bacterial superinfection are frequent. Therapy consists in the complete elimination of the parasite. The repellent Zanzarin effectively protects against sand fleas.

Prevalence and risk factors of hookworm-related cutaneous larva migrans in a rural community in Brazil.

The epidemiology of hookworm-related cutaneous larva migrans (HrCLM) in endemic communities is not well understood. To describe the prevalence of HrCLM and to identify environmental and behavioural risk factors for the infestation, two cross-sectional surveys were conducted in a small village in an endemic area of north-eastern Brazil - one in the rainy season and the other in the dry season. The members of each household were examined clinically for the presence of HrCLM, and information on possible risk factors was collected. HrCLM, which was diagnosed in 45 individuals in the rainy-season survey and in 17 in the dry-season survey, was significantly more prevalent in the rainy season (4.4% v. 1.7%; P<0.001). The age-specific prevalences peaked, at 14.9%, in infants and children aged < or = 4 years. In a logistic regression analysis, the independent risk factors for current infestation or infestation in the preceding 6 months were identified as young age (odds ratio = 0.96; 95% confidence interval = 0.94-0.98), living in a house without a solid floor (odds ratio = 1.99; 95% confidence interval = 1.22-3.23), and walking barefoot (odds ratio = 1.77; 95% confidence interval = 1.12-2.80). In the study area, therefore, HrCLM is a common parasitic skin disease in children, is associated with behavioural and environmental risk factors, and shows marked seasonality in its prevalence. Local control of HrCLM should be based primarily on the health education of mothers and the elder girls who take care of their younger siblings.

Investigations on the life cycle and morphology of Tunga penetrans in Brazil.

In the present study, the life cycle of Tunga penetrans was established in Wistar rats in the laboratory, and the morphology of the resulting developmental stages was studied by means of light and scanning electron microscopy. It was seen that the females enter at a nonfertilized stage through the skin of their hosts. Only there the copulation occurs, while females and males brought together in a Petri dish showed no interest in each other. In any way -- fertilized or not -- the females start about 6 days after penetration and hypertrophy with the ejection of eggs. While fertilized eggs proceed to development, the unfertilized ones remain arrested. The eggs are ovoid and measure about 600 x 320 mum. The larvae hatch from the eggs 1-6 days (mean 3-4) after ejection. Formation of larvae 2 took at least another day, while 4 up to 10 days more were needed until this larva starts pupation (mean 5-7 days). The formation of the adult fleas inside the puparium occurred within 9-15 days (with a maximum hatch at day 12). Adult female fleas having reached the skin of a host start blood sucking within 5 min and prepare to enter the skin. After 24 h, the flea stacked already with two thirds of its body inside the skin. After 40 h, the penetration was completed, and feeding and hypertrophical enlargement started, which was completed on day 6, when eggs became ejected. When studying the morphology of the fleas obtained from different hosts, slight variations were seen, which, however, are not significant for a species separation but may be an indication of the presence of different strains/races or the beginning of such a formation.

Structure of the Hoyle state in 12C.

The first excited 0(+) state in 12C (Hoyle state) has been predicted to be a dilute self-bound gas of bosonic alpha particles, similar to a Bose-Einstein condensate. To clarify this conjecture, precise electron scattering data on form factors of the ground state and the transition to the Hoyle state are compared with results of the fermionic molecular dynamics model, a microscopic alpha-cluster model, and an alpha-cluster model with reduced degrees of freedom (in the spirit of a Bose-Einstein condensed state). The data indicate clearly a dilute density with a large spatial extension of the Hoyle state. A closer inspection of the model calculations, which reproduce the experimental findings, reveals that the term Bose-Einstein condensation of three alpha particles must not be taken too literally.

Absence of cervical schistosomiasis among women from two areas of north-eastern Brazil with endemic Schistosoma mansoni.

Genital manifestations in schistosomiasis haematobium are common and are associated with considerable morbidity. Although Schistosoma mansoni may also cause genital disease, the frequency of this complication is not known. Cervical biopsies (N=401) and Pap smears (N=981) were therefore collected from women living in two S. mansoni-endemic areas (in the states of Alagoas and Ceará, in north-eastern Brazil). The women were screened for the presence of sexually transmitted diseases and for the presence, in their cervical smears and/or biopsies, of S. mansoni eggs. Attempts at schistosomiasis control, which began in both study areas in 1977, have led to generally low intensities of infection (<30 eggs/g faeces in 99% of infections) and community prevalences of infection that range between 1% and 52%. As no schistosome ova were detected in any of the biopsies or smears, it appears that the risk, among women, of genital manifestations of S. mansoni infection is small in areas where the parasite load in the population is low (as the result of interventions to control intestinal schistosomiasis).

Leukocytosis and blood eosinophilia in a polyparasitised population in north-eastern Brazil.

It has long been known that leukocytosis and blood eosinophilia are common in the tropical environment, but data derived from population-based studies are scarce. A study was undertaken in a fishing village in north-east Brazil where both intestinal helminthiases and parasitic skin diseases are common. Of 409 individuals studied, 128 (31.3%) were infected with one intestinal helminth or ectoparasite species, 93 (22.7%) with two, 61 (14.9%) with three, 25 (6.1%) with four and 11 (2.7%) with more than four species; no parasites were found in 91 (22.2%) individuals. Leukocyte counts ranged between 3,300 cells/microl and 16,100 cells/microl (median, 7,200 cells/microl) and eosinophil counts between 40 cells/microl and 5,460 cells/microl (median, 455 cells/microl). Eosinophilia (>500/microl) was detected in 44.7% of the individuals, and hypereosinophilia (>1,000/microl) in 12.9%. Thirty-six (8.8%) individuals showed leukocytosis. While 75% of individuals with normal eosinophil counts were considered parasite-free, only 14% with eosinophilia and 11% with hypereosinophilia did not have enteroparasites or ectoparasites. Multivariate regression showed that the probability of eosinophilia and hypereosinophilia, but not of leukocytosis, increased with the number of parasite species present. The data show that eosinophilia occurs in almost one-half of the individuals from a resource-poor setting and that it is significantly associated with the presence of intestinal helminths, but not with the presence of ectoparasites.

Field trial of the efficacy of a combination of imidacloprid and permethrin against Tunga penetrans (sand flea, jigger flea) in dogs in Brazil.

In a field trial in Brazil 17 dogs penetrated by females of the jigger flea, Tunga penetrans, were topically treated with a combination of 10% imidacloprid and 50% permethrin (Advantix), while 17 dogs remained untreated. The follow-up controls on days 7, 14, 21 and 28 post-treatment clearly showed that, beginning from day 7, the flea load in treated dogs decreased, so that most of the dogs became free of tungiasis lesions, while in the untreated group the flea load remained high. Since the dogs distribute the flea eggs throughout the village, leading to a high incidence of tungiasis in humans, treatment of dogs probably also decreases the number of cases of tungiasis in the latter.

Epidemiology and morbidity of scabies and pediculosis capitis in resource-poor communities in Brazil.

BACKGROUND: Pediculosis capitis and scabies are common parasitic skin diseases, especially in resource-poor communities, but data on epidemiology and morbidity are scanty. OBJECTIVES: To assess the prevalence, seasonal variation and morbidity of pediculosis capitis and scabies in poor neighbourhoods in north-east Brazil. METHODS: The study comprised cross-sectional surveys of a representative population of an urban slum (n = 1460) in Fortaleza, the capital of Ceará State (Brazil) and a fishing community 60 km south of the city (n = 605). Study participants were examined for the presence of scabies and pediculosis capitis. In a longitudinal study in the slum, variation of prevalence in different seasons of the year was assessed. RESULTS: Prevalence of pediculosis capitis was 43.4% in the slum and 28.1% in the fishing community. Children aged 10-14 years and females were most frequently affected. Scabies was present in 8.8% of the population in the slum and in 3.8% of the population in the fishing community. There was no consistent pattern of age distribution. Superinfection was common in patients with scabies, and cervical lymphadenopathy in patients with pediculosis capitis. Multivariate analysis showed that age < or = 15 years, being of female sex and living in the urban slum were independent factors contributing to the simultaneous coinfestation with pediculosis capitis and scabies. The longitudinal data from the urban slum showed a characteristic seasonal variation of pediculosis capitis, but no fluctuation of scabies. CONCLUSIONS: Pediculosis capitis and scabies are hyperendemic in the study areas and are associated with considerable morbidity. There is an urgent need to develop control measures for these parasitic skin diseases in resource-poor communities. This is the first community-based study describing in detail the epidemiology and morbidity of scabies and head lice infestation in Brazil.