Investigation of the in-vitro lethal effect of spilanthol on demodex and finding the most effective dose.

Demodex species are associated with many dermatological diseases, so an acaricidal agent that is effective against them and safe for skin applications may benefit many diseases. This study aims to investigate the anti-demodex potential of spilanthol, a product obtained from the Spilanthes Acmella plant, by determining the minimal effective dose for the first time in the literature. Demodex mites were obtained from 70 patients with standard superficial skin biopsy. Spilanthol extract was used at 1%, 2%, 3%, 4%, and 5%. Standard immersion oil was used for the negative control, and permethrin 5% was used for the positive control group. The dependent variable is the survival time of the mite. Comparisons with the negative control group, the anti-demodex effect demonstrated itself in all groups, creating a statistically significant difference (p < 0.001). The positive control group, had 3%, 4%, and 5% spilanthol rates which were very similar to the results with 5% permethrin (p > 0.05). Higher concentrations than 3% did not make any additional contribution to survival times. This is the first attempt to show the dose-dependent acaricidal effect of spilanthol on demodex mites. Even the 3% dose shows similar results to 5% permethrin, and no additional effect increase was observed at higher doses. Therefore, in vivo, studies may be planned with a 3% spilanthol dose for further studies.

Coverage, Usage, Physical Integrity, and Bio-efficacy of Olyset Nets in the Plateau Region, South Benin Following the 2011 Nationwide Distribution.

The present study investigated in 8 villages of the Plateau region the coverage, usage, physical integrity, and bio-efficacy of the Olyset nets distributed nationwide by the Benin's National Malaria Control Programme in July 2011. The questionnaire administered as well as the observations made in the households allowed estimating the coverage and usage rates of the 2011 Olyset nets. While their physical integrity was assessed through standard WHO methodology, their bio-efficacy was evaluated through gas chromatography, and WHO cone testing performed with the Kisumu susceptible strain. Mosquito collections through human landing catches (HLCs) were also performed in torn nets to assess if a loss of protection of sleepers occurred as the nets fabric integrity got more damaged. Nine months postdistribution, the coverage and usage rates of the 2011 Olyset nets were 67.4% (95% CI: 65.8-68.9) and 73.3% (95% CI: 70.7-75.8) respectively. About 28% of the 2011 Olyset nets were torn. A drastic drop of the insecticide quantity on the fibers of the nets [from 7.08 µg (95% CI: 5.74-8.42) to 0.2 µg (95% CI: 0.01-0.38)] as well as mortality rates <80% were observed with most nets evaluated. Moreover, the biting rates of An. gambiae s.l. (Diptera: Culicidae) inside torn nets increased in line with their fabric integrity loss. These data support the conclusion that future deployment of nets in the field must be strengthened by community sensitization on their correct use in order to postpone as much as possible appearance of holes and loss of insecticidal activity and encourage repairing of torn nets.

Vectra 3D (dinotefuran, pyriproxyfen and permethrin) prevents acquisition of Borrelia burgdorferi sensu stricto by Ixodes ricinus and Ixodes scapularis ticks in an ex vivo feeding model.

BACKGROUND: We evaluated the efficiency of an ex vivo feeding technique using a silicone membrane-based feeding chamber to (i) assess the anti-feeding and acaricidal efficacy of a spot-on combination of dinotefuran, pyriproxyfen and permethrin (DPP, Vectra® 3D) against adult Ixodes scapularis and Ixodes ricinus ticks, and to (ii) explore its effect on blocking the acquisition of Borrelia burgdorferi sensu stricto. METHODS: Eight purpose-bred dogs were randomly allocated to two equal-size groups based on body weight assessed on day 2. DPP was administered topically, as spot-on, to four dogs on day 0. Hair from the eight dogs was collected individually by brushing the whole body on days 2, 7, 14, 21, 28 and 35. On each day of hair collection, 0.05 g of sampled hair was applied on the membrane corresponding to each feeding unit (FU). Seventy-two FU were each seeded with 30 adults of I. scapularis (n = 24 FU) or I. ricinus ticks (n = 48 FU). Bovine blood spiked with B. burgdorferi sensu stricto (strain B31) was added into each unit and changed every 12 h for 4 days. Tick mortality was assessed 1 h after seeding. One additional hour of incubation was added for live/moribund specimens and reassessed for viability. All remaining live/moribund ticks were left in the feeders and tick engorgement status was recorded at 96 h after seeding, and the uptake of B. burgdorferi s.s. was examined in the collected ticks by applying quantitative real-time PCR. RESULTS: Exposure to DPP-treated hair was 100% effective in blocking B. burgdorferi s.s. acquisition. The anti-feeding efficacy remained stable (100%) against both Ixodes species throughout the study. The acaricidal efficacy of DPP evaluated at 1 and 2 h after exposure was 100% throughout the study for I. ricinus, except the 1-h assessment on day 28 (95.9%) and day 35 (95.3%). The 1-h assessment of acaricidal efficacy was 100% at all time points for I. scapularis. CONCLUSIONS: The ex vivo feeding system developed here demonstrated a protective effect of DPP against the acquisition of B. burgdorferi without exposing the animals to the vectors or to the pathogen.

Importance of Follow-Up Microscopic Examination in Hospitalized Patients with Confirmed Scabies.

We investigated the duration of positive microscopic examination in hospitalized patients with confirmed scabies in an acute care hospital. We included hospitalized patients who were diagnosed with scabies between January 2015 and June 2019. From the study period, a total of 31 patients with confirmed scabies were identified. Median age was 75 years. Of a total of 31 patients with confirmed scabies, six were discharged or transferred before getting a negative microscopic test result. Of the remaining 25 patients with negative microscopic test results, the median duration from diagnosis to a negative microscopic test result was 14 days (interquartile range, 9-17). Given that nosocomial outbreaks lead to high workload and considerable resource consumption, adequate treatment, sufficient follow-up examination, and confirmation of cure are warranted before releasing contact isolation.

Application errors associated with topical treatment of scabies: an observational study.

BACKGROUND: In recent years, there has been a significant increase in scabies infestations throughout German-speaking countries. Given the high frequency of treatment failures, the question arises as to whether topical permethrin treatment is always performed correctly. PATIENTS AND METHODS: Our department uses a fluorescent test cream to teach patients on how to correctly apply topical permethrin. In the context of a prospective observational study of 21 patients, we systematically assessed and analyzed potential application errors. RESULTS: None of the participants succeeded in adequately applying the cream to the entire skin as previously instructed. The median number of regions left untreated was six (minimum: 2; maximum: 18), which included a median body surface area of 6 % (minimum: 2 %; maximum: 30 %). With regard to predilection sites of scabies, the ankles were left untreated in 62 % of cases, followed by the interdigital spaces (toes) (33 %) and the sacral region (24 %). All patients considered the pretreatment training to be very useful. CONCLUSIONS: The present findings clearly demonstrate potential shortcomings when it comes to the application of topical antiscabies treatment. This may provide a (potentially underestimated) explanation for the large number of reports on treatment failures in this regard, which falsely suggest potential treatment resistance.

In vitro survival of scabies mites.

BACKGROUND: The correct treatment and management of scabies is expensive and time-consuming, and may have a negative impact on patients and their families. AIM: To investigate the effects of permethrin 5% cream on scabies mites, and explore mite survival times outside the human body. METHODS: We performed a nonrandomized controlled study. In total, 20 petri dishes were coated with permethrin 5% cream (treatment group) and 20 plain petri dishes (control group) each had one scabies mite placed in them, and were then observed at baseline and 3, 4, 5, 6, 7, 8 and 12 h from baseline. In the second part of our study, 30 scabies mites from infested patients were investigated in an observational experiment in 30 plain petri dishes at days 0, 3 and 4. RESULTS: Our data showed that 65% of scabies mites survived after 8 h in the treatment group compared with 75% of mites in the control group. After 12 h, 25% of mites in the treatment group and 60% in the control group were still alive. Data from the observational survival study showed that one mite was alive on day 3, but all mites were dead by day 4. CONCLUSIONS: This study showed no significant effects of mite survival times with 5% topical permethrin after 8 h, while its efficacy was stronger and significant after 12 h. We recommend the isolation of all mite-infested items for at least 4 days.

EFFICACY OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) TREATMENT FOR CATTLE FEVER TICKS IN SOUTHERN TEXAS, USA.

White-tailed deer (Odocoileus virginianus) serve as a host for cattle fever ticks (Rhipicephalus [Boophilus] microplus and Rhipicephalus [Boophilus] annulatus; CFTs); therefore, deer are a concern for CFT control programs in southern Texas, US. Systemic (oral delivery of ivermectin) and topical (permethrin on pelage) treatment devices have been developed for white-tailed deer; however, the efficacy of these treatment options has not been determined for CFTs in southern Texas. Our objectives were to evaluate the effectiveness of CFT treatment strategies by 1) measuring exposure rates of deer to the acaricides permethrin and ivermectin, 2) determining the relationship between CFTs on deer and exposure to the acaricides, and 3) determining if photos from remote cameras at medicated bait sites can be used as a measure of acaricide treatment. We captured 327 deer at four sites in southern Texas. Deer visitation to medicated bait sites was monitored using remote cameras from March 2010 to February 2012. There was no relationship between the presence of permethrin and the probability of being infested with CFTs (P≥0.336). The probability of infestation with CFTs decreased as serum ivermectin levels increased for male (n=18, P=0.098) and female (n=33, P<0.001) deer. Our results indicate ivermectin may be more effective in treating CFTs than permethrin; thus it would be worthwhile to develop topical acaricides other than permethrin for treating white-tailed deer in southern Texas.

The efficacy and safety of permethrin 2.5% with tea tree oil gel on rosacea treatment: A double-blind, controlled clinical trial.

BACKGROUND: Rosacea is a chronic skin condition that typically affects the face and it results in redness and inflammation. The main risk factors of this disease are Demodex folliculorum, living in the pilosebaceous units. AIMS: To evaluate the efficacy and safty of permethrin 2.5% in combination with tea tree oil (TTO) topical gel versus placebo on Demodex density (Dd) and clinical manifestation using standard skin surface biopsy (SSSB) in rosacea patients. PATIENT/METHODS: In this double-blind, randomized clinical trial, 47 papulopustular rosacea patients were enrolled, with 35 patients finishing the 12 weeks of treatment. Each patient used permethrin 2.5% with TTO on one side of the face and a placebo on the other, twice daily for 12 weeks. SSSB, photography and clinical rosacea scores according to National Rosacea Society, as well as adverse drug reaction (ADRs) were reported at the baseline, 2nd, 5th, 8th, and 12th weeks. RESULTS: A total of 47 patients were enrolled with papulopustular rosacea, and 35 patients finished the study. The effects of permethrin 2.5% with TTO gel on mite density were significant at week 5, 8, 12 (P value = .001). Clinical features and global assessments showed papules, pustules and nontransient erythema had improvement in drug group after 12 weeks (P values <.05). The improvement of burning and stinging and dry appearance was greater than the placebo gel (P value <.05). Itching in placebo group was significantly more than other group (P value = .002). CONCLUSION: Administration of permethrin 2.5% with TTO gel demonstrated good efficacy and safety in rosacea. This topical gel inhibited the inflammatory effects of rosacea and reduced Demodex mite.

Severe pediculosis capitis in a nursery school girl / Pediculosis capitis grave en una niña inscrita en una guardería

Pediculosis capitis is the most frequent ectoparasitosis around the world. The infestation is caused by Pediculus humanus capitis (head louse), which affects hair, scalp, and skin. It rarely presents with more symptoms and in the majority of the cases, it shows a benign course if treated properly. We present the case of a nursery school girl with head lice infestation for 18 months. She did not improve after the shampoo treatment. This case was associated with furunculosis, skin lesions, multiple adenopathies, and anemia. Initially, the presence of boils, alopecia, and lymphadenopathy was evident. The persistence of pediculosis capitis and intense scratching induced changes on skin integrity, facilitating opportunistic bacterial superinfection that led to impetiginization, furunculosis, excoriations, hematic scabs, anemia, alopecia, and lymphadenopathies. Pediculosis capitis affected the patient triggering psychological, economic, social, and other health problems. The patient presented uncommon symptoms (furunculosis, anemia, fever, alopecia, and adenopathies) resulting from the persistence of risk factors and the absence of head inspection and mechanical removal of insects. The education about the risk factors, as well as sanitary controls, are essential to contain the infestation.

La pediculosis capitis es la ectoparasitosis más frecuente a nivel mundial. La infestación es causada por Pediculus humanus capitis (piojo de la cabeza) y afecta el cabello, el cuero cabelludo y la piel. Rara vez se manifiesta con otro tipo de sintomatología y, por lo general, su curso es benigno si se trata adecuadamente. Se presenta el caso de una menor con pediculosis capitis de 18 meses de evolución, asociada con forúnculos, lesiones cutáneas, múltiples adenopatías y anemia, que no mejoró tras la aplicación del champú. Inicialmente, llamó la atención la presencia de forúnculos, alopecia y adenopatías. La persistencia de la pediculosis capitis y el rascado intenso alteraron la integridad de la epidermis y facilitaron las infecciones secundarias por bacterias patógenas y oportunistas que produjeron impétigo, forunculosis, excoriaciones, costras hemáticas, anemia, alopecia y linfadenopatías. La pediculosis capitis afectó notoriamente a la paciente al causarle problemas psicológicos y de salud, agudizados por su condición económica y social. La paciente presentó manifestaciones clínicas poco frecuentes (forunculosis, anemia, fiebre, alopecia y adenopatías), lo cual se vio facilitado por la persistencia de los factores de riesgo y el hecho de que no se le inspeccionaba la cabeza ni se removían los insectos. La educación sobre los factores de riesgo y el control sanitario es indispensable para controlar la infestación.

Gut DNA Virome Diversity and Its Association with Host Bacteria Regulate Inflammatory Phenotype and Neuronal Immunotoxicity in Experimental Gulf War Illness.

Gulf War illness (GWI) is characterized by the persistence of inflammatory bowel disease, chronic fatigue, neuroinflammation, headache, cognitive impairment, and other medically unexplained conditions. Results using a murine model show that enteric viral populations especially bacteriophages were altered in GWI. The increased viral richness and alpha diversity correlated positively with gut bacterial dysbiosis and proinflammatory cytokines. Altered virome signature in GWI mice also had a concomitant weakening of intestinal epithelial tight junctions with a significant increase in Claudin-2 protein expression and decrease in ZO1 and Occludin mRNA expression. The altered virome signature in GWI, decreased tight junction protein level was followed by the presence an activation of innate immune responses such as increased Toll-like receptor (TLR) signaling pathways. The altered virome diversity had a positive correlation with serum IL-6, IL-1ß, and IFN-γ, intestinal inflammation (IFN-γ), and decreased Brain-Derived Neurotrophic Factor (BDNF), a neurogenesis marker. The co-exposure of Gulf War chemical and antibiotic (for gut sterility) or Gulf War chemical and Ribavirin, an antiviral compound to suppress virus alteration in the gut showed significant improvement in epithelial tight junction protein, decreased intestinal-, systemic-, and neuroinflammation. These results showed that the observed enteric viral dysbiosis could activate enteric viral particle-induced innate immune response in GWI and could be a novel therapeutic target in GWI.

Treatment of Demodex-associated inflammatory skin conditions: A systematic review.

Bacterial folliculitis, rosacea, and other common skin conditions have been linked to infestation by Demodex mites (human demodicosis). Currently, there is little guidance for treatment of inflammatory conditions associated with demodicosis. Thus, the objective of this review is to evaluate the efficacy and safety of treatments utilized for Demodex infestation. PubMed (1946 to January 2019) and Embase (1947 to January 2019) were searched with the following term combinations: Demodex mites, Demodex folliculitis, demodicosis, Demodex folliculorum, or Demodex brevis and articles evaluating treatment of body surface colonization with Demodex mites were included. Common interventions used for Demodex infestation include metronidazole-based therapies, permethrin, benzoyl benzoate, crotamiton, lindane, and sulfur. Short courses of metronidazole taken orally have shown efficacy in reducing Demodex density. Additionally, topical administration of permethrin daily or twice daily was shown to be efficacious across multiple studies. Crotamiton and benzyl benzoate were also efficacious treatments. Several therapies were associated with mild-to-moderate skin irritation. Due to limited data, no standard of care can be identified at this time. Efficacious treatment options may include permethrin, crotamiton, benzyl benzoate, and oral metronidazole; however, long-term efficacy has not been established.

Comparative efficacy of three pediculicides to treat head lice infestation in primary school girls: a randomised controlled assessor blind trial in rural Iran.

BACKGROUND: Head lice infestation (Pediculosis) is one of the most important health challenges particularly in primary school-aged children. It is often present among 6-11-year-old students in various tropical and temperate regions of the world. The aim of this study was to examine epidemiologic indices and comparative analysis of two pyrethroid-based and one non-chemical pediculicide products on head lice treatment of primary school girls in a rural setting of Fars province, south Iran, as part of a randomized controlled assessor blind trial. METHODS: Before treatment, infested students were screened using plastic detection combs to find live head lice. Three independent parallel groups, each with about 25 participants (#77) were eventually twice with a week apart treated with either 1% permethrin, 0.2% parasidose (d-phenothrin) or 4% dimeticone lotion preparations. In each case, a questionnaire form was completed on epidemiologic factors. Data were registered after a fortnight from primary scalp treatment and re-inspection on days 2, 6, 9 and 14. Data analyses were performed using Chi-square test with a P-value < 0.05 being taken as statistically significant. RESULTS: From 3728 inspected students, 87 (2.33%) girls were infested with head lice, Pediculus humanus capitis De Geer, 1778. Ten students dropped out pertaining to exclusion criteria. No significant correlation was found between head lice infestation level and hair length, hair style, itching, nationality, age, settlement site and baths; but there was a significant relationship between age and hair style (P = 0.027). The efficacy values on each of the above re-inspection days from each of the three treatments were 81, 74, 70 and 63% for permethrin; 83, 92, 100 and 100% for dimeticone; and 96, 88, 96 and 92% for d-phenothrin; respectively. A quartile difference in efficacy of permethrin relative to dimeticone on day 14 represented the scale of head lice resistance to permethrin treatment. There were significant statistical differences in case re-inspection days 9 (P = 0.008) and 14 (P = 0.003) post treatment. Only two dropout cases, one non-compliant and the other lost before the second-week treatment, from permethrin trial were observed following two applications a week apart. CONCLUSIONS: Dimeticone lotion had the fullest efficacy (100%) among all treatments. This high cure rate was attributed to the low level of infestation and the extent of patients' involvement. Parasidose swiftly ameliorated the infested cases by the second day since initial treatment. Female third grade students were the most infested cohort. TRIAL REGISTRATION: Current Controlled Trials- IRCT2016041627408N1 , Dated: 21-08-2017.

Presumptive tick paralysis in 2 American Miniature horses in the United States.

RATIONALE: Tick paralysis has not been reported in horses in North America. CLINICAL FINDINGS: Two American Miniature horses were examined for progressive weakness and recumbency. Numerous ticks (Dermacentor variabilis) were found on both horses. Horse 1 was recumbent (grade 5/5 gait deficit) on presentation, whereas Horse 2 was standing but ataxic (grade 4/5 gait deficit) and tetraparetic. Both horses had decreased tongue and tail muscle tone, and had normal spinal reflexes. Cerebrospinal fluid cytology was normal. Equine herpesvirus-1 testing was negative. PERTINENT INTERVENTIONS: Ticks were removed within 24 hours of presentation. Both horses were treated topically with permethrin. Supportive care included fluid therapy, treatment for corneal ulceration, and frequent repositioning during recumbency. OUTCOME: Within 48 hours of tick removal, both horses were neurologically normal. CLINICAL RELEVANCE: Ours is the first reported case of presumptive tick paralysis in horses in North America. Although rare, tick paralysis should be considered in horses presented with acute-onset weakness progressing to recumbency.

Permethrin Cream for the Treatment of Demodex Blepharitis.

PURPOSE: To evaluate the safety and efficacy of permethrin 5% cream for the treatment of Demodex blepharitis. METHODS: Patients with confirmed Demodex blepharitis were prospectively recruited and treated with permethrin 5% cream for 6 months. Blepharitis symptoms, ocular examination findings, ocular surface disease index, and ex vivo eyelash Demodex counts were regularly assessed. RESULTS: Twenty-three patients were recruited, of which 2 were lost to follow up and 21 entered the analysis. Mean patient age was 57.2 ± 16.8 years (range: 24-82 years), and 13 (62%) were women. Mean Demodex counts improved after treatment from 1.36 ± 1.233 to 0.48 ± 0.6 parasites per eyelash (P = 0.03), and the overall blepharitis symptoms score improved from 42.9 ± 22 to 32.7 ± 21 (P = 0.01). Improvement in disease symptoms (scored on a scale between 0 and 4) was noted including feeling of dry eye (2.85 ± 1.3-1.85 ± 1.7, P = 0.006), discharge (1.86 ± 1.7-1.00 ± 1.1, P = 0.040), and dandruff-like debris (1.69 ± 1.7-0.9 ± 1.6, P = 0.033), as well as clinical findings including a decrease in scaling (on a scale of 1-5; 1.43 ± 0.9-0.86 ± 0.7, P = 0.006) and corneal staining with fluorescein (on a scale of 1-4; 1.29 ± 0.4-1.05 ± 0.2, P = 0.040). No change in the ocular surface disease index score was noted (37.5 ± 24.1-41.63 ± 42.5, P = 0.913), and no adverse events were reported. CONCLUSIONS: Treatment of Demodex blepharitis with permethrin 5% cream resulted in a decrease in parasite burden and improvement in blepharitis signs and symptoms, with no reported adverse events. Permethrin might be a safe and effective alternative for the treatment of blepharitis associated with Demodex infection.

Plasma Protein and Lipoprotein Binding of Cis- and Trans-Permethrin and Deltamethrin in Adult Humans and Rats.

The majority of residents of the United States, Canada, and Europe are exposed to pyrethroids, the most commonly used class of insecticides. Surprisingly little is known about key aspects of their pharmacokinetics, including their mode of transport in the systemic circulation. This study tested the hypothesis that pyrethroids are transported by both plasma lipoproteins and proteins, similarly to other highly lipophilic environmental contaminants. Other aims were to characterize the binding of representative type I and II pyrethroids, and to compare their binding to rat versus human plasma. Binding of 14C-labeled cis-permethrin (CIS), trans-permethrin (TRANS) and deltamethrin (DLM) to proteins and lipoproteins was measured by sequential extraction of spiked plasma with isooctane, 2-octanol, and acetonitrile. Binding of DLM, CIS, and TRANS to plasma proteins and lipoproteins was linear from 250 to 750 nM; concentrations present in the plasma of orally dosed rats. Binding of DLM to high-density lipoprotein was twice that to low-density lipoprotein. Binding of DLM, CIS, and TRANS was ∼2-fold greater to proteins than to lipoproteins of rat and human plasma; albumin was primarily responsible for protein binding. Higher total binding of each pyrethroid to human (∼90%) than to rat (∼80%) plasma resulted from higher protein binding in human plasma. This was attributable in part to the higher albumin/protein content of human plasma. Rat albumin exhibited lower pyrethroid binding capacity than did human albumin. The results of this investigation indicate that albumin and lipoproteins play a major role in binding and transport of pyrethroids in the systemic circulation of both rats and humans.

Management of scabies.

Scabies is a common infestation worldwide, affecting persons of any age and socioeconomic status. In Singapore, it is more common in institutions rather than in homes. The two variants are classic scabies and crusted scabies, with the latter having a significantly higher mite burden. Early identification, isolation of index patients and prophylactic treatment of contacts are essential in dealing with the outbreak. Locally, most primary care practitioners make the diagnosis based on visual inspection and clinical examination. A skin scrape is done to confirm the diagnosis, especially in atypical presentations. Scabietic mites, eggs or faeces can be seen on microscopy. The usual treatment for adult scabies in Singapore is the use of topical malathion or permethrin. A combination of topical permethrin and oral ivermectin is used for crusted scabies.