The effect of phototherapy on Demodex density: a case-control study.

BACKGROUND: Human Demodex mites, Demodex folliculorum and Demodex brevis, are microorganisms that reside in the pilosebaceous units, usually without causing symptoms. Phototherapy has been linked to demodicosis in previous studies. We aimed to determine whether there was an increase in the frequency of demodicosis and Demodex density after 20 phototherapy sessions. METHODS: A case-control study was conducted with 32 participants who received narrowband ultraviolet B or ultraviolet A-1 therapy for various dermatological indications. Standardized skin surface biopsies were performed before and after phototherapy to assess Demodex density. The presence of Demodex-related skin conditions was assessed before phototherapy. A statistical analysis was performed to compare the Demodex densities and prevalence of demodicosis between the baseline and 20th session of phototherapy. RESULTS: No significant change was observed in Demodex density after 20 sessions of phototherapy. The average Demodex density before treatment was 2.75 ± 4.48 (/cm2 ), and after treatment, it was 2.85 ± 4.81 (/cm2 ), indicating no significant difference (P = 0.879). The percentage of patients with demodicosis in at least one region of the face was 28.1% (9/32) before treatment, and after treatment, it was 31.3% (10/32), with no significant difference (P = 1.00). CONCLUSIONS: Our findings contradict previous studies that suggested an increased Demodex density and demodicosis prevalence after phototherapy. The data from previous studies are open to debate due to their selected samples, designs, and interpretations regarding the phototherapy-immunosuppression-Demodex relationship. Larger-scale longitudinal studies conducted on a homogeneous sample are warranted to better understand the relationship between phototherapy and demodicosis.

The Investigation of Prevalence of Demodex spp. in University Students: The Case of the Faculty of Health Sciences

Objective: The aim of this study was to determine the prevalence of Demodex spp. in college students, mostly adolescent individuals. Methods: A questionnaire including questions about the risk factors of Demodex spp. was administered to college students. Samples were taken with Standard Superficial Skin Biopsy method and examined under light microscope. Results: Presence of Demodex spp. was detected in 160 (42.7%) students out of 375 totally; 126 out of 291 nursing students (43.3%) and 34 out of 84 midwifery students (40.5%). It was detected in 47.3% of males and 40.2% of females. There was a statistically significant difference in terms of the prevalence of Demodex spp. between those who used foundation cream/make-up products and those who did not, and between those who removed hair and those who did not (p<0.05). There was no relationship between other variables and Demodex spp. prevalence. Conclusion: It is concluded that Demodex spp. is very common among college students in Kars. Dermatologists should also consider the existence of Demodex spp. in the etiology and pathogenesis of dermatoses which develops in the facial region of individuals in this group of age.

Ocular demodicosis: A review. / Demodicosis ocular: una revisión.

Demodex folliculorum and Demodex brevis are ectoparasites that inhabit the skin of humans. They have been related to alterations in the ocular surface, such as, dysfunction of Meibomian glands, blepharitis, chalazion, etc. Ocular demodicosis is characterised by the pathognomonic presence of cylindrical dandruff at the base of the eyelashes, and various symptoms including, among others, itching, lacrimation, and hyperaemia. A bibliographic review was carried out on the role of Demodex spp. in ocular disease, including publications made by the scientific society between 2005 and 2018. A significant relationship was found between prevalence and incidence of Demodex spp. in eye diseases. D. folliculorum is usually found more frequently than D. brevis in ocular infestation, with the prevalence or incidence of infestation by both species increasing with the age of the patient. In patients with blepharitis or other infectious diseases of the ocular surface, unresolved with antibacterial treatment, the search for Demodex spp. should be considered.

¿Qué hacemos ante un brote de escabiosis en un hospital? / What we do in front of a scabies outbreak in a hospital setting?

La escabiosis o sarna es una enfermedad de la piel producida por Sarcoptes scabiei; puede ir aumentando el número de casos, hasta llegar a producir verdaderas epidemias1. Se procede a describir las actuaciones del Servicio de Prevención de Riesgos Laborales de un hospital ante un brote de escabiosis ocurrido en una planta de hospitalización, con afectación de trabajadores sanitarios, tras el contacto con un paciente fuente (sospecha clínica y epidemiológica de escabiosis)

The scabies is a skin disease produced by Sarcoptes scabiei; it has been an increase on the number of cases, reaching eventually an epidemic level. We proceed to describe the measures taken by the laboral risk prevention service of a hospital against an outbreak of scabies happened in the hospitalization floor, with infection of the hospital workers after having contact with a source patient (clinic and epidemiologic scabies is suspected)

Risk factors for Psoroptes ovis mange on Belgian Blue farms in Northern Belgium.

The parasitic mite Psoroptes ovis causes important economic losses in Belgian Blue cattle. Because mange problems vary significantly between farms, a cross-sectional questionnaire survey and subsequent farm visits were performed to identify potential risk factors for P. ovis infections on Belgian Blue farms in Flanders, Belgium. The questionnaire was sent to 1800 beef farms to evaluate the presence and severity of psoroptic mange in the herd and to assess farm management practices, including antiparasitic treatments. Subsequently, about 10% of the farms with a completed questionnaire were visited to validate the questionnaire and to retrieve supplementary information on additional management parameters, such as barn infrastructure and climate. Associations between parasitism and putative risk factors were assessed by logistic regression. Out of 1800 contacted farms, 680 (38%) completed questionnaires were received. Data were collected from 238 barns during 66 farm visits. The questionnaire results demonstrated a high farm prevalence of mange (74%; 95% CI (70.7-77.3)) and half of the farmers declared that the problem was difficult to control. Nevertheless, in only 14% of the barns a high scratching index was recorded and in most of the sampled animals (80%) the affected body surface was less than 10%. This indicates that despite the high prevalence and the difficulty to control the infection, clinical signs were often quite moderate. Logistic regression analyses of the questionnaire and the farm visit data suggested that heavily infested farms treat more intensively against mange. On most farms mange occurred the whole year round and more problems with mange were found on farms where a higher number of animals were purchased per year. In addition, the disease was more prevalent when the animals had a lower hygiene score. This score was strongly correlated with environmental hygiene, indicating that transmission of mites from the environment to the animals should not be underestimated. Conflicting results were obtained on the effect of supplementing minerals on the occurrence of mange. In this study, temperature, light intensity and relative humidity in the barns, ventilation systems, barn infrastructure, animal stocking rate and blood mineral levels were not indicated as risk factors for mange. In conclusion, maintaining a good animal hygiene and if possible, avoiding introduction of cattle may help to control psoroptic mange in Belgian Blue cattle.

Mites (Mesostigmata: Spinturnicidae and Spelaeorhynchidae) associated with bats in northeast Brazil.

In this article, we present the results of a study about mites associated with bats collected in the State of Pernambuco, northeast Brazil. Of the 331 bats collected, 23 were found naturally infested by mites, corresponding to an overall prevalence of 6.9% (95% confidence interval: 4.5-10.2). Four mite species were collected from seven bat species. The following mite-bat associations were recorded: Periglischrus acutisternus Machado-Allison on Phyllostomus discolor Wagner; Periglischrus ojastii Oudemans on Carollia perspicillata L.; Periglischrus iheringi Oudemans on Artibeus lituratus (Olfers), Artibeus planirostris Spix, Platyrrhinus lineatus (E. Geoffroy), and Sturnira lilium (E. Geoffroy); and Spelaeorhynchus praecursor Neumann on C. perspicillata. This study definitively confirms the presence of S. praecursor in Pernambuco and records for the first time the presence of three spinturnicid species (i.e., P. acutisternus, P. ojastii, and P. iheringi) in northeast Brazil.

[Survey and treatment of pulmonary acariasis among the workers involving in traditional Chinese medicinal materials].

OBJECTIVE: To investigate the prevalence of pulmonary acariasis among the employees working on traditional Chinese medicinal materials and observe the effect of treatment. METHODS: History inquiry, detection of mites in sputum, blood examination for eosinophils and specific antibodies, x-ray chest film were carried out for 327 workers involving in traditional Chinese medicinal materials. Mites were found in sputum in 121 persons who were then treated with metronidazole, twice a day with a daily dosage of 0.8g for seven days as a course of treatment. Two courses were conducted with an interval of 7-10 day. Prevalence and morbidity in different groups of occupation, age, and sex were analyzed. RESULTS: The overall infection rate of mites in sputum was 37.0% (121/327) with an average morbidity of 12.5% (41/327). Among the four types of worker investigated, the highest infection rate (51.8%), and morbidity (18.6%) were in those working in transfer warehouse; the second highest infection rate (40.7%) and morbidity (15.7%) were in employees in factory of Chinese traditional medicine. Both groups showed a significant difference with others (chi2inf=11.36, P< 0.01; chi2inc=11.36, P<0.01). Higher morbidity was found in the middle-aged ones and those with more years of service. No difference was found between males and females (chi2=0.31, P>0.05). After treatment with metronidazole, 88.4% showed negative in sputum examination for mites and the efficacy of the treatment for pulmonary acariasis was 92.3%. CONCLUSIONS: Employees engaged in traditional Chinese medicinal materials are one of the groups at the highest risk of pulmonary acariasis. Metronidazole is effective in treating the infection.

Diarrhea and acaroid mites: a clinical study.

AIM: To explore the characteristics of diarrhea caused by acaroid mites. METHODS: Acaroid mites in fresh stools of 241 patients with diarrhea were separated by flotation in saturated saline. Meanwhile, skin prick test, total IgE and mite-specific IgE were detected in all patients. RESULTS: The total positive rate of mites in stool samples of the patients was 17.01 % (41/241), the positive rates of mites in male and female patients were 15.86 % (23/145) and 18.75 % (18/96), respectively, without significant difference (P>0.05). The percentage of skin prick test as "+++", "++", "+", "+/-" and "-" was 9.13 % (22/241), 7.47 % (18/241), 5.81 % (14/241), 4.98 % (12/241) and 72.61 % (175/241), respectively. The serum levels of total IgE, mite-specific IgE in patients with and without mites in stool samples were (165.72+/-78.55) IU/ml, (132.44+/-26.80) IU/ml and (145.22+/-82.47) IU/ml, (67.35+/-45.28) IU/ml, respectively, with significant difference (P<0.01). The positive rate of mites in stool samples in staffs working in traditional Chinese medicine storehouses or rice storehouses (experimental group) was 26.74 % (23/86), which was significantly higher than that (11.61 %, 18/155) in people engaged in other professions (chi(2)=8.97, P<0.01). CONCLUSION: Acaroid mites cause diarrhea and increase serum levels of total IgE and mite-specific IgE of patients, and the prevalence of diarrhea caused by acaroid mites is associated with occupations rather than the gender of patients.

Acaroid mite, intestinal and urinary acariasis.

AIM: To investigate epidemiology and pathogenic mite species of intestinal and urinary acariasis in individuals with different occupations. METHODS: A total of 1994 individuals were tested in this study. History collection, skin prick test and pathogen identification were conducted. The mites were isolated from stool and urine samples by saturated saline flotation methods and sieving following centrifugation, respectively. RESULTS: Among the 1994 individuals examined, responses to the skin prick test of "+++", "++", "+","+/-" and "-" were observed at frequencies of 3.96 % (79), 3.21 % (64), 2.31 % (46), 1.25 % (25) and 89.27 % (1780), respectively. A total number of 161 (8.07 %) individuals were shown to carry mites, with 92 (4.61 %) positive only for stool samples, 37 (1.86 %) positive only for urine samples and 32 (1.60 %) for both. The positive rate of mites in stool samples was 6.22 % (124/1994), being 6.84 % (78/1140) for males and 5.39 % (46/854) for females. No gender difference was observed in this study (chi(2)=1.77, P>0.05). The mites from stool samples included Acarus siro, TyroPhagus putrescentiae, Dermatophagoides farinae, D. pteronyssinus, Glycyphagus domesticus, G. ornatus, Carpoglyphus lactis and Tarsonemus granaries. The positive rate of mites in urine samples was 3.46 % (69/1994). The positive rates for male and female subjects were found to be 3.95 % (45/1140) and 2.81 % (24/854) respectively, with no gender difference observed (chi(2)=1.89, P>0.05). Mites species in urine samples included Acarus siro, Tyrophagus putrescentiae, T. longior, Aleuroglyphus ovatus, Caloglyphus berlesei, C. mycophagus, Suidasia nesbitti, Lardoglyphus konoi, Glycyphagus domesticus, Carpoglyphus lactis, Lepidoglyphus destructor, Dermatophagoides farinae, D. pteronyssinus, Euroglyphus magnei, Caloglyphus hughesi, Tarsonemus granarus and T. hominis. The species of mites in stool and urine samples were consistent with those separated from working environment. A significant difference was found among the frequencies of mite infection in individuals with different occupations (chi(2)=82.55, P<0.001), with its frequencies in those working in medicinal herb storehouses, those in rice storehouse or mills, miners, railway workers, pupils and teachers being 15.89 % (68/428), 12.96 % (53/409), 3.28 % (18/549), 2.54 % (6/236), 5.10 % (13/255) and 2.56 % (3/117), respectively. CONCLUSION: The prevalence of human intestinal and urinary acariasis was not associated with gender, and these diseases are more frequently found in individuals working in medicinal herb, rice storehouses or mills and other sites with high density of mites. More attention should be paid to the mite prevention and labor protection for these high-risk groups.

Sensibilizaçäo atópica em escolares e adultos de Curitiba, Paraná / Atopic sensitization among schoolchildren and adults in Curitiba, Paraná

Objetivo: Determinar a freqüência de sensibilizaçäo atópica à Dermatophagoides pteronyssinus (DP) e Lolium multiflorum ( Lolium ) em escolares e adultos residentes em Curitiba, Paraná. Casuística e método: Foram avaliados 3271 escolares (13 e 14 anos), provenientes de 43 escolas de Curitiba e 3041 adultos (idade > 20anos) funcionários, médicos do Hospital de Clínicas e adultos da UFPR. Realizou-se teste cutâneo alérgico por puntura (TCA) com dois extratos alergênicos: DP 5000 AU/mL e Lolium 1:30 peso/volume (Bayer Corporation, USA). A leitura foi feita após 15 minutos e considerada reaçäo positiva aquela com pápula igual ou superior a 3 mm de diâmetro. Resultados: Observou-se uma freqüência de TCA positivo para DP em 31,3 por cento das crianças e 38,9 por cento dos adultos e para Lolium 4,7 por cento das crianças e 15,4 por cento dos adultos. A sensibilizaçäo exclusiva ao DP em crianças foi de 28,1 por cento, ao Lolium 1,5 por cento e a ambos 3,2 por cento. Em adultos, os valores foram de 26,8 por cento de sensibilidade exclusiva ao DP e 3,3 por cento ao Lolium e para ambos de 12,1 por cento. Conclusäo: Os resultados revelam a alta freqüência de sensibilizaçäo aos ácaros da poeira domiciliar na populaçäo geral e maior freqüência de reaçäo ao pólen de gramíneas em adulto do que em crianças.

Treatment of psoroptic mange with reference to epidemiology and history.

Treatment methods in the last century involved the use of substances such as sulphur, mercury, hellebore, arsenic, nicotine and others, applied in various ways. The advent of dips in 1843 signalled an advance. However, the biology of the mite, Psoroptes ovis, the epidemiology of sheep scab and the lack of persistence of the acaricides necessitated repeated laborious treatments to ensure success. In 1947 this changed with the use of organo chlorines (OCs) which had up to 3 months residual activity. The use of OCs led to the eradication of psoroptic mange of sheep in USA. Organo phosphates (OPs) were introduced in the late fifties and synthetic pyrethroids (SPs) in the early seventies. In 1985, due to sheep tissue residues, lindane (OC) was withdrawn from the market and this greatly reduced the capacity for effective sheep scab control. Before the arrival of the endectocidal avermectin, ivermectin in 1978 and its successful use as an acaricide in 1992, control of psoroptic mange was limited to plunge dipping. In 1994 moxidectin, a milbemycin, was found to be effective and to have the added benefit of at least 4 weeks persistent activity. Another avermectin doramectin was shown, in 1995, to successfully treat scab and recently an ivermectin bolus has been introduced which has a 100 days' activity and is fully therapeutic and prophylactic. Strict attention to detail in the use of injectable products is essential in order to achieve satisfactory results. Work is progressing on the use insect growth regulators (IGRs) and also on naturally occurring substances such as linalool, neem and lavender oil. At the CVRL Dublin, promising results have been achieved with neem and some IGRs. Other areas of interest are allemones, synergists, microclimate manipulation, sheep breed resistance and vaccines. Successful control depends on epidemiological knowledge, accurate diagnostic techniques, intimate knowledge of the mite's life cycle, its behaviour on and off the host, its macro and molecular biology, the nature of the pathogenesis of the disease, sheep husbandry practices, nutritional and environmental factors; also farmer awareness and attitudes. The variable responses of sheep to the mite, the unpredictable incubation period, course, manifestations and outcome make this an intriguing and perplexing disease. Ways to overcome these problems and to achieve possible eradication are discussed.

Control of Psoroptes cuniculi in captive white-tailed deer with ivermectin-treated corn.

Psoroptes cuniculi, the ear mite of domestic rabbits, was collected from captive white-tailed deer (Odocoileus virginianus). This is the first report of rabbit ear mite infestations in white-tailed deer in Oklahoma or Texas (USA). In addition to moderate infestations in their ears, two 4-yr-old bucks, two 3-yr-old does, and seven 4-yr-old does showed patchy areas of alopecia along the sides and brisket. Both bucks also had patchy areas of alopecia around the base of antlers. Ear mites were eradicated from all deer except from one doe by providing ivermectin-treated corn to the deer at a rate of 1,000 g (equivalent to 200 mcg/kg of ivermectin)/day/deer for several days. The ear mite infestation in the one doe was eradicated by intramuscularly injection with ivermectin at 400 mcg/kg. After treatment with the ivermectin and eradication of the mites, the alopecia improved and eventually was eliminated. The ivermectin-treated corn also controlled all internal nematode parasites in the deer.