New chemistries for the control of human head lice, Pediculus humanus capitis: A mini-review.

Pediculus lice represent one of the longest and most prevalent parasitic infestations of humans. Head lice are an economic and social concern whereas body lice pose a more serious public health threat. Significant progress has been made in the study of human lice over the last 10 years, allowing for new approaches in their control. An in vitro rearing system has made it possible to maintain insecticide-susceptible and -resistant reference strains, which allowed an in depth study of pediculicide resistance, including its underlying molecular mechanisms and the detection and monitoring of resistance. The generation of inbreed strains facilitated the efficient sequencing, assembly and annotation of the genomes and transcriptomes of both lice. The use of functional genomics and reverse genetics elucidated the genetics involved in the evolution of resistance and the discovery of novel target sites for the development of new pediculicides. In this review, four new effective pediculicide products, each with different mode of action and unique chemistries, will be presented. They have been found to be safe and selective, and control resistant lice. As such, they meet the criteria necessary to be used in rotations as a sustainable resistance management strategy.

Effectiveness and tolerability of a squalane and dimethicone-based treatment for head lice.

Head lice (Pediculus humanus capitis) are worldwide obligate human ectoparasites, with high implications in pediatrics. In Europe, first-line topical neurotoxic insecticidal therapeutic strategies are being replaced by topical physically acting agents as the first-choice treatment. Safety of the active ingredients and high efficacy in a one-time single-dose treatment with a brief treatment application time are key issues for consumer use and effective compliance. The aim of this study was to assess the in vitro efficacy of a newly developed squalane and dimethicone-based pediculicidal formula, against motile head lice and eggs after 2 and 5 min immersion in the product, as well as its skin tolerance and acceptability under dermatological and pediatric expert control in children with atopic skin. The results indicate that at both time points, 100% mortality rate of head lice crawling stages and late-stage eggs was achieved. The formula was well tolerated and suitable for children with atopic skin from 12 months of age. Showing high in vitro efficacy and good skin acceptability, this solution is presented as a new safe alternative therapy for treatment of head lice infestations.

Head louse infestations before and during the COVID-19 epidemic in Israel.

Head louse infestations caused by Pediculus humanus capitis (Phthiraptera: Pediculidae) are a public health problem in developing and developed countries worldwide. Head to head contact is by far the most common mode of lice transmission. In March 2020, WHO declared the COVID-19 outbreak as a pandemic. Starting from March 2020, the Israeli government established mandatory isolation for extensive periods including closure of school systems for very long time. The aim of the project was to compare the pediculicide sale numbers before the COVID-19 epidemic with those starting of the epidemic in 2020, as a possible marker for changing epidemiology of head lice during the COVID pandemic. Data were collected from a large pharmacy chain in Israel, which provided the actual sales of pediculicides during the years 2010-2020. During the period 2010-2019 a significant increase of pediculicide sales from 281,986 - 498,107 was observed, the highest number being from 2019. In 2020, this number dropped to 294,477, a significant drop compared to previous years and to 2019. The results of this study suggest that head louse infestations are increasing in the last years, while the extended isolation of children due to COVID-19 influenced significantly the infestation rate of children with head lice.

Paediatrics: how to manage pediculosis capitis.

Background: Pediculosis capitis is a common human parasitic infestation in childhood. This article aims to provide a narrative updated review on the management of pediculosis capitis. Methods: A PubMed search was performed with Clinical Queries using the key terms "pediculosis capitis" OR "head lice" OR "head louse". The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews published within the past 10 years. The search was restricted to articles published in English literature. The information retrieved from the search was used in the compilation of the present article. Results: Topical permethrin and pyrethrin formulated with piperonyl butoxide are the pediculicides of choice in areas where resistance to these products is low. When resistance to these products is suspected based on local levels of resistance or when treatment with these products fails despite their correct use, and reinfestation does not seem to be responsible, other topical treatment options include malathion, benzyl alcohol, dimethicone, spinosad and ivermectin. Wet combing should be considered for children younger than 2 years. Oral ivermectin and trimethoprim/sulfamethoxazole should be reserved for patients who do not respond to appropriate topical pediculicides. Conclusion: Many topical pediculicides are effective for the treatment of pediculosis capitis. The use of some of these pediculicides is limited for safety reasons, especially in children younger than 2 years. Resistance to pediculicides, especially those with a neurotoxic mode of action, is another concern which may limit the use of some of these pediculicides. New products should be evaluated for effectiveness and safety. Wet combing is time-consuming and should not be used as the sole intervention in the general population.

Eficácia do extrato concentrado contendo Saccharum officinarum L: Poaceae, Azadirachta indica A. Juss. Meliaceae, e Eucaliptus spp Myrtaceae, sobre Pediculus capitis De Geer, (Anoplura: Pediculidae) / Effectiveness of concentrate extract containing Saccharum Officinarum L: Poaceae, Azadirachta Indica A. Juss. Meliaceae, And Eucaliptus Spp Myrtaceae Against Pediculus Capitis De Geer, (Anoplura: Pediculidae)

O objetivo deste trabalho foi avaliar a eficácia do extrato concentrado contendo Saccharum officinarum L. Poaceae, Azadirachta indica A. Juss. Meliaceae, e Eucaliptus spp Myrtaceae sobre Pediculus capitis De Geer Pediculidae. Foram coletados mil e trinta e cinco piolhos da cabeça de crianças infestadas por Pediculus capitis de creches da Região Metropolitana do Recife, Estado de Pernambuco, Brasil. Para realização do teste utilizou-se três grupos com trezentos e quarenta e cinco piolhos cada referentes aos produtos, extrato concentrado (EC), inseticida piretróide (PI) e controle (C). Os piolhos foram imersos em solução dos produtos por três minutos e em seguida secos. A mortalidade foi monitorada em diferentes momentos, por um período de vinte e quatro horas. O extrato concentrado matou todos os piolhos antes de doze horas e uma média de 60,28 por cento (208/345) de mortalidade do EC ocorreu entre três e seis horas, a maior parte da mortalidade do PI foi observada 24 h após o tratamento. Os resultados mostraram que o extrato contendo Saccharum officinarum, Azadirachta indica, e Eucaliptus spp constitui-se como uma potente ferramenta no controle do Pediculus capitis.

The aim of this work was to evaluate the effectiveness of concentrate extract containing Saccharum officinarum L. Poaceae, Azadirachta indica A. Juss. Meliaceae, and Eucaliptus spp Myrtaceae against Pediculus capitis De Geer Pediculidae. A thousand and thirty five head lice were collected from children with Pediculus capitis infestation from some day care centers at Metropolitan Region of Recife, Pernambuco State, Brazil. The tests were performed in three groups with three hundred forty five lice each one according to product, concentrate extract (CE), pyrethroid insecticide (PI) and control (C). The immersing head lice in the diluted products for three minutes, washing off products and dry the insects were used. The mortality of lice was monitored at different points in time, for a period of twenty four hours. Concentrate extract killed all head lice after twelve hours and an average of 60.28 percent (208/345) of lice mortality of the CE occurred between three and six hours, while the mortality of PI was observed 24 h after treatment. The results showed the extract containing Saccharum officinarum, Azadirachta indica, and Eucaliptus spp could be a potent tool in the control of Pediculus capitis.