Head lice: impact of COVID-19 and slow recovery of prevalence in Cambridgeshire, UK.

Following school closures and changes in contact behavior of children and adults a reduced head louse prevalence has been reported from across the globe. In parallel, sales of treatments were observed to fall, partly because of supply problems of some products following the pandemic, but this did not appear to result in more cases of infestation. Surveys of schools in and around Cambridge, UK, found that infestation rates were significantly reduced particularly in city schools compared with similar surveys conducted before the COVID-19 pandemic.

Do some families act as a reservoir of head lice in the community? Surveys for prevalence and insecticide resistance suggest this is the case.

In response to increasing complaints of head louse infestation in the area of Cambridge, UK, in the mid-1990s, a series of prevalence surveys in selected schools coupled with collection of lice were commissioned by the local health authority. Carers of infested children were provided with advice on treatment by school nurses. Lice collected during these surveys were tested in the laboratory for evidence of resistance to insecticides.

Head lice: an inexpensive bioassay for use as guidance for healthcare workers monitoring treatment failures for insecticide resistance (1994-1999).

Head lice, Pediculus humanus capitis De Geer (Psocodea: Pediculidae) that failed to respond to pyrethroid insecticide-based treatment products were first identified in London and Cambridge, UK, in 1993 after which reports of treatment failure arose throughout the UK. There was a need amongst healthcare workers for a rapid detection method for resistance that could be used at the community level. A laboratory service was set up so that health professionals could send lice by overnight post for bioassay testing for resistance.

Physically Acting Treatments for Head Lice-Can We Still Claim They Are 'Resistance Proof'?

Head lice worldwide have developed resistance to insecticides, prompting the introduction of a range of alternative treatments including plant extracts and natural and synthetic oils. Clinical studies of physically acting treatments showed them to be highly effective when first introduced, and a widely held, but unsubstantiated, belief is that lice are unlikely to develop resistance to them. However, this ignores possibilities for natural selection of traits enabling lice to survive exposure.

Sucking lice and spiracular transpiration: turning a liability into a benefit and a necessity.

Sucking lice feed on blood and therefore ingest more water than they require for maintaining hydration. This water must be excreted; however, unlike other blood-feeding insects, they do not produce urine but do become dehydrated within hours if unable to feed. Using human clothing lice and head lice, Pediculus humanus ssp.

Opportunistic myiasis of nestling common blackbirds by Lucilia silvarum.

Previously, the Marsh greenbottle blowfly, Lucilia silvarum Meigen (Diptera: Calliphoridae), has been implicated in myiasis of anurans but not of mammals or birds. This report describes an incident of opportunistic myiasis of nestling common blackbirds, Turdus merula (Passeriformes: Turdidae), by L. silvarum larvae in association with an infestation by the hematophagous maggot Neottiophilum praeustum (Diptera: Piophilidae).

''Anti-lice Protector Shampoo'': Clinical Study Shows Lack of Efficacy of Coconut Oil Derivatives in the Elimination of Head Louse Infestation.

Objective: Coconut oil and its derivatives are widely thought to kill head lice by occlusion and asphyxiation. There is no evidence in support of coconut derivative-based products sold to treat pediculosis. This study was designed to test one such product.

Head louse egg and nit remover-a modern "Quest for the Holy Grail".

Background: The eggs of head lice are fixed to the hair of their hosts by means of a persistent glue-like fixative that is not chemically bound to the substrate. Eggshells stuck to hairs after successfully treating the infestation are a cosmetic issue and a source of misunderstanding about whether the infestation is eliminated. Hitherto, no effective treatment to loosen louse eggs and nits has been found.

Laboratory and clinical trials of cocamide diethanolamine lotion against head lice.

Context. During the late 1990s, insecticide resistance had rendered a number of treatment products ineffective; some companies saw this as an opportunity to develop alternative types of treatment. We investigated the possibility that a surfactant-based lotion containing 10% cocamide diethanolamine (cocamide DEA) was effective to eliminate head louse infestation.

A Novel Nit Comb Concept Using Ultrasound Actuation: Preclinical Evaluation.

Nit combing and removal of head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), eggs is a task made more difficult because "nit combs" vary in efficiency. There is currently no evidence that the binding of the eggshell to the hair can be loosened chemically and few hair treatments improve the slip of the louse eggs along the hair. Ultrasound, applied through the teeth of a nit comb, may facilitate the flow of fluids into the gap between the hair shaft and the tube of fixative holding louse eggs in place to improve lubrication.

Re: Treatment of Parasitic Skin Diseases with Dimeticones A New Family of Compounds with a Purely Physical Mode of Action.

The article on use of dimeticone for treatment of epidermal parasitic skin diseases is potentially confusing and misleading because, in a practical sense, only head louse infestation can be treated with this material. Scabies mites are unaffected by silicones and use of dimeticone against other ectoparasites may have unwanted side effects such as anaphylactiform reactions or increased risk of pathogen transmission.

Head lice.

Introduction: Head louse infection is diagnosed by finding live lice, as eggs take 7 days to hatch (but a few may take longer, up to 13 days) and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings or of lower socioeconomic group. Factors such as longer hair make diagnosis and treatment more difficult.

Comparison of phenothrin mousse, phenothrin lotion, and wet-combing for treatment of head louse infestation in the UK: a pragmatic randomised, controlled, assessor blind trial.

In this investigation of effectiveness of an alternative pediculicide dosage form, we recruited 228 children and 50 adult participants from Bedfordshire, UK, to a randomised, controlled, assessor blind trial comparing two insecticide products with mechanical removal of lice as a control group.  Participants using insecticide were treated with either the investigative 0.5% phenothrin mousse, for 30 minutes, or 0.

Prevention of head louse infestation: a randomised, double-blind, cross-over study of a novel concept product, 1% 1,2-octanediol spray versus placebo.

Objectives: To determine whether regular use of a spray containing 1,2-octanediol 1%, which has been shown to inhibit survival of head lice, is able to work as a preventive against establishment of new infestations.

Setting: Randomised, double-blind, cross-over, community study in Cambridgeshire, UK.

Participants: 63 male and female schoolchildren aged 4-16 years judged to have a high risk of recurrent infestation.

Can head louse repellents really work? Field studies of piperonal 2% spray.

Background. Many families find regular checking of children's heads for head louse infestation too onerous and would prefer to be able to prevent infestation by use of a topical application that deters lice from infesting the head. Identification in the laboratory of a repellent activity for piperonal provided the basis for developing a spray product to repel lice.

0.4% dimeticone spray, a novel physically acting household treatment for control of cat fleas.

The cat flea, Ctenocephalides felis, is the most important ectoparasite of cats and dogs worldwide as a cause of irritation and health problems. Most products to control these pests in the household environment rely upon a combination of neurotoxic insecticides and insect growth regulators to inhibit development of flea eggs and larvae into adults. However, some of these are affected by problems of insecticide resistance as well as public concerns about their potential for toxicity in domestic use.

Tocopheryl acetate 20% spray for elimination of head louse infestation: a randomised controlled trial comparing with 1% permethrin creme rinse.

Background: Tocopheryl acetate is viscous oily fluid used in a range of preparations for skin and scalp care in Italy. Observational and in vitro data have suggested a high level of efficacy against head louse infestation. The purpose of this investigation was to confirm the activity of tocopheryl acetate in a clinical setting in comparison with a standard widely used preparation.

Single application of 4% dimeticone liquid gel versus two applications of 1% permethrin creme rinse for treatment of head louse infestation: a randomised controlled trial.

Background: A previous study indicated that a single application of 4% dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin.

Methods: We have performed a single centre parallel group, randomised, controlled, open label, community based trial, with domiciliary visits, in Cambridgeshire, UK.

1,2-Octanediol, a novel surfactant, for treating head louse infestation: identification of activity, formulation, and randomised, controlled trials.

Background: Interest in developing physically active pediculicides has identified new active substances. The objective was to evaluate a new treatment for clinical efficacy.

Methods And Findings: We describe the selection of 1,2-octanediol as a potential pediculicide.

Head lice.

Introduction: Head lice can only be diagnosed by finding live lice, as eggs take 7 days to hatch and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings, longer hair, and of lower socioeconomic group.

Methods And Outcomes: We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review).

Dimeticone 4% liquid gel found to kill all lice and eggs with a single 15 minute application.

Background: Dimeticone 4% lotion is an effective and widely accepted treatment for head louse infestation. However, it is a highly mobile fluid that some people find difficult to apply and is mainly left on the hair for 8 hours or overnight. User preference is for a more manageable and viscous product that can be used with a short application time.

Soya oil-based shampoo superior to 0.5% permethrin lotion for head louse infestation.

Background: This was a randomized, assessor-blind, controlled comparison of a soya oil- based medical device shampoo with a medicinal permethrin lotion in an alcohol vehicle for treatment of head louse infestation to generate data suitable for a regulatory submission to achieve reimbursable status for the shampoo product.

Methods: We treated 91 children and adults, divided between two sites, on two occasions 9 days apart. Participants washed their hair and towel-dried it before treatment.