Staying Ahead of Head Lice: Pediculosis Treatment Updates

Pediculosis (head lice) infections are one of the more sensitive issues that may involve the school nurse. In the 3- to 11-year-old age group in the United States, head lice infections are common and can elicit anxiety in students, parents, and school personnel. Head lice do not transmit any communicable diseases and therefore exclusion from school and "no nit" policies are not warranted. Treatment and management for head lice include a range of over-the-counter products and prescription topical and oral medications. Nonpharmacologic and alternative treatments do exist; however, many do not have established efficacy studies, and some can be costly. The school nurse plays an integral role in providing education related to treatment and environmental recommendations for families affected by head lice. Through this education, the nurse can also reduce the stigma and anxiety many feel around the subject of head lice infections.

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.

Infestations, Bites, and Insect Repellents

Infestations and arthropod bite reactions in children are common reasons for presentation to pediatric health care providers. Infestations in children include head lice, scabies, and other mites. Fleas and bed bugs are common causes of bite reactions in children, and papular urticaria is a chronic, recurrent eruption resulting from delayed hypersensitivity to a variety of insect bites. Both infestations and bite reactions may result in severe pruritus with associated sleep disturbance and can be a source of significant distress for patients and families. In this review, we discuss infestations and bite reactions affecting pediatric patients, along with the approach to treatment and prevention of these conditions. [Pediatr Ann. 2020;49(3):e124-e131.].

Is Allopreening a Stimulus-Driven Defense Against Ectoparasites?

Allopreening occurs when 1 bird preens another bird. The behavior is normally directed at the head and neck of the recipient, i.e., regions that the bird cannot self-preen. Studies of penguins, pigeons, and other groups of birds suggest that allopreening plays a role in the control of ectoparasites, such as ticks and feather lice. However, it is not known whether allopreening increases in response to increases in parasite load, or whether it is a programmed response that occurs independently of parasite load. We conducted a laboratory experiment using wild-caught rock pigeons (Columba livia) to test the relationship between ectoparasite load and allopreening rate. We added feather lice (Columbicola columbae) to captive pigeons and tested for changes in allopreening rates compared to control birds with no lice added. Allopreening rates did not change in response to the addition of lice. Interestingly, however, our data revealed a negative correlation between allopreening and self-preening rates.

High level efficacy of lufenuron against sea lice (Lepeophtheirus salmonis) linked to rapid impact on moulting processes

Drug resistance in the salmon louse Lepeophtheirus salmonis is a global issue for Atlantic salmon aquaculture. Multiple resistance has been described across most available compound classes with the exception of the benzoylureas. To target this gap in effective management of L. salmonis and other species of sea lice (e.g. Caligus spp.), Elanco Animal Health is developing an in-feed treatment containing lufenuron (a benzoylurea) to be administered prior to seawater transfer of salmon smolts and to provide long-term protection of salmon against sea lice infestations. Benzoylureas disrupt chitin synthesis, formation, and deposition during all moulting events. However, the mechanism(s) of action are not yet fully understood and most research completed to date has focused on insects. We exposed the first parasitic stage of L. salmonis to 700 ppb lufenuron for three hours and observed over 90% reduction in survival to the chalimus II life stage on the host, as compared to vehicle controls. This agrees with a follow up in vivo administration study on the host, which showed >95% reduction by the chalimus I stage. Transcriptomic responses of salmon lice exposed to lufenuron included genes related to moulting, epithelial differentiation, solute transport, and general developmental processes. Global metabolite profiles also suggest that membrane stability and fluidity is impacted in treated lice. These molecular signals are likely the underpinnings of an abnormal moulting process and cuticle formation observed ultrastructurally using transmission electron microscopy. Treated nauplii-staged lice exhibited multiple abnormalities in the integument, suggesting that the coordinated assembly of the epi- and procuticle is impaired. In all cases, treatment with lufenuron had rapid impacts on L. salmonis development. We describe multiple experiments to characterize the efficacy of lufenuron on eggs, larvae, and parasitic stages of L. salmonis, and provide the most comprehensive assessment of the physiological responses of a marine arthropod to a benzoylurea chemical.

Effect of a health education program on reduction of pediculosis in school girls at Amphoe Muang, Khon Kaen Province, Thailand

BACKGROUND

Pediculosis caused by head lice (Pediculus humanus capitis) infestation is still an important health problem in schoolchildren, especially girls, worldwide, including in Thailand. Although pediculicidal agents effectively kill head lice, the re-infestation rate is still high. Thus, prevention is an important strategy for any sustainable control program. We aimed to develop and evaluate the efficacy of a health education program for increasing knowledge, changing attitudes and promoting preventive practices to reduce prevalence of pediculosis among school girls in Amphoe Muang, Khon Kaen, northeastern Thailand.

METHODOLOGY

Six schools were selected using multistage simple randomization and were allocated into intervention or control groups. A total of 267 girls was enrolled from these schools. A "knowledge, attitude and practice" (KAP) questionnaire, consent forms and health education materials were constructed and tested by experts and in one pilot school before the main investigation. Baseline prevalence of adult lice and nits was determined. The health education package was given only to the intervention group. The KAP questionnaire was re-evaluated at two months after intervention.

RESULTS

At baseline, the prevalence and intensity of head lice infestation, and the KAP scores did not differ significantly between the two groups. After re-evaluation at two months, the KAP score was significantly greater in the intervention group. A significant decrease of the infestation rate from 59% to 44% was observed in the intervention group, whereas infestation increased in the control group (from 56% to 65%). The incidence of new cases in the intervention group (6.14%) was lower than in the control group (12.62%).

CONCLUSION

These findings indicated that the newly-established health education package is an effective tool for increasing KAP and reducing head lice infestation in school girls. Efforts to combat pediculosis in schoolchildren elsewhere may consider including this, or a similar, health education package in their programs.

Efficacy of Peer Education for Adopting Preventive Behaviors against Head Lice Infestation in Female Elementary School Students: A Randomised Controlled Trial

Background

Pediculosis is a common parasitic infestation in students worldwide, including Iran. This condition is more prevalent in populous and deprived communities with poor personal hygiene. This study sought to assess the efficacy of peer education for adopting preventive behaviors against pediculosis in female elementary school students based on the Health Belief Model (HBM).

Methods

A total of 179 female fifth grade students were selected using multistage random sampling and were randomly allocated to control and intervention groups. A standard questionnaire was designed and administered to collect baseline information. An educational intervention was then designed based on the conducted needs assessment. The educational program consisted of three sessions, held by peers for the intervention group. The questionnaire was re-administered one month after the intervention. Independent and paired t-test, Pearson’s correlation coefficient, and regression analysis were applied as appropriate.

Results

The two groups had no significant differences in the scores of knowledge, HBM constructs, or behavior before the intervention. After the intervention, however, the mean scores of all parameters significantly improved in the intervention group.

Conclusion

Peer education based on HBM is an effective strategy to promote preventive behaviors against pediculosis in among fifth grade female elementary school students in Iran.

No-Nit Policies in Schools: Time for Change

No-nit policies that exist in many schools throughout the United States were established years ago based on fear and misinformation, rather than scientific evidence. Children who are found to have live lice are no more infectious on the day of diagnosis than they had been prior to the discovery. Transmission of head lice requires close personal contact, which is not common in the school setting. To date, no scientific literature exists to support the exclusion of children from school due to head lice infestation. Therefore, there is a need to develop updated school policies using research-based evidence to determine the best method of treating infestations while allowing children to remain in school.

Does allopreening control avian ectoparasites?

For birds, the first line of defence against ectoparasites is preening. The effectiveness of self-preening for ectoparasite control is well known. By contrast, the ectoparasite control function of allopreening-in which one birds preens another-has not been rigorously tested. We infested captive pigeons with identical numbers of parasitic lice, and then compared rates of allopreening to the abundance of lice on the birds over time. We documented a negative relationship between rates of allopreening and the number of lice on birds. Moreover, we found that allopreening was a better predictor of louse abundance than self-preening. Our data suggest that allopreening may be a more important means of ectoparasite defence than self-preening when birds live in groups. Our results have important implications for the evolution of social behaviour.

Effect of Environmental Conditions and Toxic Compounds on the Locomotor Activity of Pediculus humanus capitis (Phthiraptera: Pediculidae)

In this work, we evaluated the effect of environmental variables such as temperature, humidity, and light on the locomotor activity of Pediculus humanus capitis. In addition, we used selected conditions of temperature, humidity, and light to study the effects of cypermethrin and N,N-diethyl-3-methylbenzamide (DEET) on the locomotor activity of head lice. Head lice increased their locomotor activity in an arena at 30°C compared with activity at 20°C. When we tested the influence of the humidity level, the locomotor activity of head lice showed no significant differences related to humidity level, both at 30°C and 20°C. Concerning light influence, we observed that the higher the intensity of light, the slower the movement of head lice. We also demonstrated that sublethal doses of toxics may alter locomotor activity in adults of head lice. Sublethal doses of cypermethrin induced hyperactivated responses in adult head lice. Sublethal doses of DEET evocated hypoactivated responses in head lice. The observation of stereotyped behavior in head lice elicited by toxic compounds proved that measuring locomotor activity in an experimental set-up where environmental conditions are controlled would be appropriate to evaluate compounds of biological importance, such as molecules involved in the host-parasite interaction and intraspecific relationships.

In Vitro and In Vivo Evaluation of Infestation Deterrents Against Lice

The human head louse is a cosmopolitan ectoparasite and frequently infests many people, particularly school-age children. Due to widespread pyrethroid resistance and the lack of efficient resistance management, there has been a considerable interest in the protection of uninfested people and prevention of reinfestation by disrupting lice transfer. In this study, two nonclinical model systems (in vitro and in vivo) were used to determine the efficacy of the infestation deterrents, Elimax lotion and Elimax shampoo, against human head lice or poultry chewing lice, respectively. With in vitro assessments, female head lice exhibited significantly higher avoidance responses to hair tufts treated with either of the test formulations, which led to significantly higher ovipositional avoidance when compared with female lice on control hair tufts. Additionally, both formulations were determined to be competent infestation deterrents in a competitive avoidance test in the presence of a known attractant (head louse feces extract). In in vivo assessments using a previously validated poultry model, Elimax shampoo was determined to be an efficacious deterrent against poultry chewing lice within Menopon spp. and Menacanthus spp.

Behavioural adaptations of argulid parasites (Crustacea: Branchiura) to major challenges in their life cycle

Fish lice (Argulus spp.) are obligate ectoparasites, which contrary to most aquatic parasites, retain the ability to swim freely throughout the whole of their life. In fish farms, they can quickly increase in numbers and without effective control cause argulosis, which results in the reduced growth and survival of their fish hosts. The morphology of Argulus spp, including their sensory organs, is suitable for both parasitism and free-swimming. By spending a considerable amount of time away from their host, these parasites risk being excessively dispersed, which could endanger mating success. Here we present a review of recent studies on the behaviour of Argulus spp, especially the aggregative behaviour that mitigates the dilution of the parasite population. Aggregation of parasites, which is especially important during the period of reproduction, occurs on different scales and involves both the aggregation of the host and the aggregation of the parasites on the host. The main behavioural adaptations of Argulus spp, including searches for hosts and mates, host manipulation and host choice, are all focused on the fish. As these ectoparasites repeatedly change hosts and inflict skin damage, they can act as vectors for fish pathogens. The development of environmentally friendly measures for the control and prevention of argulosis needs to take into account the behaviour of the parasites.

Demystifying pediculosis: school nurses taking the lead

The treatment of Pediculosis capitis, or head lice, is fraught with misinformation, myths, and mismanagement. Common myths include the need to exclude children from school, the need to remove all visible nits ("no-nit" policies), the need for massive environmental cleaning, that head lice live for long periods of time, and that schools are a common location for lice transmission. Head lice are a common childhood nuisance, causing embarrassment and emotional trauma in both children and families. This article explores and challenges the commonly held beliefs about the identification, management, and treatment of Pediculosis by presenting current recommended evidence-based practice. It also challenges pediatric nurses, and school nurses in particular, in alignment with the National Association of School Nurses (NASN) Position Statement on Pediculosis Management in the School Setting, to act as change agents for reasonable and effective school policies and practices.

Headlice eradication as everyday engagement with science: An analysis of online parenting discussions

This paper focuses on the way in which people deploy scientific knowledge alongside other resources in everyday interactions. In the UK headlice are common amongst schoolchildren, and treatment is viewed as a parental responsibility. Choice between treatment options lies with individual parents, with official guidance giving no clear steer. In the face of this combination of responsibility and uncertainty, users of an online parenting forum justify their actions using a variety of resources, including claims to scientific knowledge of both headlice and the action of various treatments, but also drawing on the authority of having direct experience, trust in brand-named products and generalised suspicion of "chemical" treatments. These discussions occasion expression of knowledge as part of portraying oneself as a responsible parent, and thus while they do not necessarily represent public knowledge about science more generally, they do offer a useful site to explore what people do with science.

Socioeconomic status, family background and other key factors influence the management of head lice in Norway

How head lice infestations are managed by households is an important but generally neglected issue in head lice research. In the present study, we investigate actions taken against head lice by Norwegian households in association with socioeconomic status, family background, school-related variables and other key factors. Repeat questionnaires distributed to caretakers of the same elementary school children during a 2-year period enabled us to study both previous head lice management and any changes in this management through time. Households from 12 schools spanning the main socioeconomic variation found in Norway participated in the study. All students with active head lice infestation were treated in the four investigated periods. Most caretakers used a thorough head lice checking technique and informed others of own infestation. Checking frequency was low as most children were inspected less than monthly. The best determinant of increased checking frequency and thoroughness was personal experience with head lice. The increased awareness, however, seemed to be somewhat short-lived, as there was a decrease in checking frequency and thoroughness within 1 year after infestation. Personal experience with head lice also increased general knowledge related to the parasite. Parents born in developing countries checked their children for head lice more frequently, although less thoroughly, informed fewer contacts when infested, used pediculicides preventively more often and knew less about head lice than parents born in developed countries. Households with highly educated mothers had a lower checking frequency, but their knowledge and willingness to inform others was high. Single parents were more concerned about economic costs and kept children home from school longer while infested than other parents. As head lice management varied among socioeconomic groups and with parental background, differentiated advice should be considered in the control of head lice. The biannual focus on head lice during the 2 years of investigation increased checking thoroughness, while checking frequency remained unchanged. Based on the results, we suggest new head lice management guidelines for health authorities.

Handbook Of Non Drug Intervention (HANDI) Project Team. Wet combing for the eradication of head lice

Manual removal (using conditioner and comb or a wet comb) can be used in the treatment of head lice. Head lice infestation (Pediculosis humanus capitis) is a common problem. It is diagnosed by visualising the lice. As half of people infested with head lice will not scratch, all people in contact with a person affected with head lice should be manually checked for infestations. Wet combing is easily and safely performed at home, but persistence is needed. This article describes the process of head lice removal using a wet comb. It has NHMRC Level 2 evidence of efficacy and no serious adverse effects have been reported.

Efficacy of the treatments used for the control of Caligus rogercresseyi infecting Atlantic salmon, Salmo salar L., in a new fish-farming location in Region XI, Chile

Caligus rogercresseyi is the most important parasite affecting Atlantic salmon and rainbow trout farming in sea water in Chile. After the outbreaks of the infectious salmon anaemia recorded in Region X from 2007, the salmon industry has expanded southwards to Region XI, where 60% of Atlantic salmon in Chile is now produced. In parallel with the relocation of salmon production, sea lice infestation has also spread to Region XI, and today C. rogercresseyi is the most serious threat to the salmon-farming industry in this region. The results obtained through a year of monitoring between September 2007 and August 2008 on a farm located in the 'Las Guaitecas Archipelago' in Region XI (44°S; 74°W) showed that treatments with emamectin benzoate and deltamethrin did not give the expected control of Caligus. Failures of the treatments were associated with the loss of sensitivity recorded for C. rogercresseyi to emamectin benzoate in Region X. In addition, a major influence was the lack of delousing coordination measures with the neighbouring farms sharing the same area in that period.

Housing and dustbathing effects on northern fowl mites (Ornithonyssus sylviarum) and chicken body lice (Menacanthus stramineus) on hens

Hen housing (cage or cage-free) did not impact overall abundances of northern fowl mites, Ornithonyssus sylviarum (Canestrini & Fanzago) (Acari: Macronyssidae), or chicken body lice, Menacanthus stramineus (Nitzsch) (Phthiraptera: Menoponidae). Cage-free hens received a dustbox with sand plus diatomaceous earth (DE), kaolin clay or sulphur. Weekly use varied from none to 100% of hens; 73% of hens used the dustbox at least once. Ectoparasite populations on dustbathing hens (users) were compared with those on non-user cage-free and caged hens. All materials reduced ectoparasites on user hens by 80-100% after 1 week of dustbox use. Diatomaceous earth and kaolin failed to reduce ectoparasites on non-user hens, and ectoparasites on user hens recovered after dustbox removal. A sulphur dustbox eliminated mites from all hens (including non-users) within 2-4 weeks. Residual sulphur controlled mites until the end of the experiment (up to 9 weeks), even after the dustbox was removed. Louse populations on hens using the sulphur dustbox were reduced in 1-2 weeks. Residual sulphur effects were less evident in lice, but the use of a sulphur dustbox by a higher proportion of hens extended louse control to all hens. This is the first experimental study to show that bird dustbathing in naturally and widely available dust materials (particularly kaolin) can suppress ectoparasites and thus the behaviour is probably adaptive.

Does sunlight enhance the effectiveness of avian preening for ectoparasite control?

Preening is a bird's first line of defense against harmful ectoparasites. Ectoparasites, in turn, have evolved adaptations for avoiding preening such as hardened exoskeletons and escape behavior. Earlier work suggests that some groups of ectoparasites, such as feather lice, leave hiding places in feathers that are exposed to direct sunlight, making them more vulnerable to preening. It is, therefore, conceivable that birds may choose to preen in direct sunlight, assuming it improves the effectiveness of preening. Using mourning doves and their feather lice, we tested 2 related hypotheses; (1) that birds with access to direct sunlight preen more often than birds in shade, and (2) that birds with access to direct sunlight are more effective at controlling their ectoparasites than birds in shade. To test these hypotheses, we conducted an experiment in which we manipulated both sunlight and preening ability. Our results provided no support for either hypothesis, i.e., birds given the opportunity to preen in direct sunlight did not preen significantly more often, or more effectively, than did birds in shade. Thus, the efficiency of preening for ectoparasite control appears to be independent of light intensity, at least in the case of mourning doves and their feather lice.

Hats off to success: changing head lice policy

Pediculosis at school is an emotional and contentious issue. Many school nurses do not feel prepared to take on the task of changing long-standing school policy, even in the light of solid evidence to do so. This article explores one school nurse's experience in changing lice policy for her district.

Of lice and math: using models to understand and control populations of head lice

In this paper we use detailed data about the biology of the head louse (pediculus humanus capitis) to build a model of the evolution of head lice colonies. Using theory and computer simulations, we show that the model can be used to assess the impact of the various strategies usually applied to eradicate head lice, both conscious (treatments) and unconscious (grooming). In the case of treatments, we study the difference in performance that arises when they are applied in systematic and non-systematic ways. Using some reasonable simplifying assumptions (as random mixing of human groups and the same mobility for all life stages of head lice other than eggs) we model the contagion of pediculosis using only one additional parameter. It is shown that this parameter can be tuned to obtain collective infestations whose characteristics are compatible with what is given in the literature on real infestations. We analyze two scenarios: One where group members begin treatment when a similar number of lice are present in each head, and another where there is one individual who starts treatment with a much larger threshold ("superspreader"). For both cases we assess the impact of several collective strategies of treatment.

Treatment and control of ectoparasites in sheep

Ectoparasites are a major concern in sheep flocks, wherever sheep are kept. Techniques to control and eradicate lice, ked, or scab have been available since the beginning of the 20th century, but the parasites still exist. Sheep scab (Psoroptes ovis) was eradicated from Australia in the late 1800s, before many of the more effective chemicals were available, and sheep ked is believed to also have been eradicated. Sheep scab has also been eradicated from North America. This article provides an overview of the common ectoparasites of sheep, effective products to control these parasites, and management factors that affect the success of these treatments.

[Occurrence of head pediculosis and its control in children's homes in selected provinces of Poland in the years 2007-2009]

Despite civilisation development and the easy access to pediculicides, head pediculosis remains still the social, hygienic and medical problem. In the years 2007 - 2009 in children's homes in selected provinces of Poland the questionnaire survey on the occurrence of head pediculosis and its control have been conducted. From 127 orphanages 61 (48.03%) sent back fulfilled questionnaire. The infestation level ranged from 4.63% (Swietokrzyskie Province, 2009) until 17.63% (Mazowieckie Province 2007) in the surveyed children's homes. The most head pediculosis cases were observed among girls 6 - 12 years old in children's homes from all regions investigated. The profile of pediculicides used had been changed during our study: in the first year the most often pediculicides with the insecticide permethrin were used. In the next years their use decreased, but the use of herbal and silicone pediculicides increased. The efficacy of anti-louse product was the most important factor for the respondents when they choose an pediculicide.

The use of mercury against pediculosis in the Renaissance: the case of Ferdinand II of Aragon, King of Naples, 1467-96

The hair samples of Ferdinand II of Aragon (1467-1496), King of Naples, whose mummy is preserved in the Basilica of San Domenico Maggiore in Naples, showed a high content of mercury, with a value of 827ppm. Furthermore, examination using a stereomicroscope and a scanning electron microscope (SEM) of head and pubic hairs of Ferdinand II, revealed a lice infestation. The reasons for the massive presence of the mercury in the king's hair are discussed and contemporary literature regarding the use of this metal in medical therapies and in cosmetic practices is analysed. As a result, the high value of mercury in the hair of Ferdinand II can be attributed to antipediculosis therapy, applied as a topic medicament. This case represents an important finding for the history of medicine, because demonstrates that in the Renaissance mercury was applied locally not only to treat syphilis, as well attested by direct and indirect sources, but also to prevent or eliminate lice infestation.

Head lice

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2002 clinical report on head lice was published by the American Academy of Pediatrics, patterns of resistance to products available over-the-counter and by prescription have changed, and additional mechanical means of removing head lice have been explored. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting.

A survey on knowledge and perceptions regarding head lice on a sample of teachers and students in primary schools of north and south of Italy

High rates of pediculosis are found in every part of the world. The age-range most affected is between 3 and 12 years. No-nit policies are ineffective in preventing infestations. On the other hand, misdiagnosis and overuse of pediculicides, increase resistance to treatment. Lack of information leads people to consider this kind of infestation to be associated to low social classes and immigrants. This research has been implemented to find out about the information level on pediculosis on a sample of students (722) and teachers (408) of some primary schools in northern and southern Italy, and to highlight the role of personal aspects such as age, gender, cultural level, geographical position which may influence this topic and, eventually, allow the use of the correct knowledge in developing appropriate procedures within the school district. Data was obtained through a questionnaire containing 21 multiple choice questions for the teachers and 14 for the students. Standard descriptive statistics were computed. chi2 tests were applied to highlight statistical association among observed variables; test for the difference of two proportions were applied to confirm significant differences among the observed proportions. The level of information for students seems to be, approximately, the same both for northern and southern Italy. There was a slight prevalence of correct answers from southern teachers, probably because the phenomenon of pediculosis has a positive trend of growth in the south. The number of correct answers was, for all, on average about 60.0%; a negative result in itself considering the simplicity of the questions. Knowledge about the biology of the louse was virtually absent. The area of prevention showed lack of information and need for improvement. Most of the teachers believe that there are specific products that can prevent infestation by louse. Most of the teachers have information which does not come from scientific sources. Students receive some short and incomplete information from their parents. Deficiencies in teachers' knowledge indicate that they are inadequately equipped to manage lice infestation. Educational interventions with teachers and families and, as a consequence, with students should be taught at school to allow a correct understanding of the pediculosis, increasing the teachers' competence and, consequently, as soon as the infestation should manifest, a rapid alert of the Health Service so that proper treatment could be provided.

Update on treatments for head lice

Head lice infestation is common, and mainly affects children of primary school age. Treatments include conventional chemical insecticides; fine tooth louse combs; and fluid preparations that work by a physical rather than chemical mode of action. However, each of these fails to eradicate head lice in some patients. Other disadvantages include the long contact time required for certain preparations e.g. 8 hours and the time commitment for combing regimens. Isopropyl myristate 50% in cyclomethicone solution (Full Marks Solution - SSL International) is a new fluid treatment with a physical mode of action that uses a 10-minute contact time. Here, we consider this product in the context of updating advice we gave in 2007 on treatments for head lice.

Pediculus humanus capitis: an update

Head lice infestation, or pediculosis capitis, caused by Pediculus humanus capitis, is a common health concern. In the US, where pediculosis capitis is the most prevalent parasitic infestation of children, 6 to 12 million people are affected every year. Pediculosis capitis remains confined to the scalp. Scalp pruritus is the cardinal symptom, although patients with lice can be asymptomatic. Pruritus with impetiginization should prompt the physician to look for lice or viable nits. All close contacts should be examined. Treatment directed at killing the lice and the ova should be considered only if active lice or viable eggs are observed. The three fundamental effective treatment options for head lice are topical pediculicides, wet combing, and oral therapy. Spraying or fogging a home with insecticides or pediculicides is not recommended.

[Physicians' knowledge in Israel on the biology and control of head lice]

BACKGROUND

Health providers such as physicians, nurses and pharmacists should be knowledgeable about the biology of head lice and the ways to control them effectively, in order to reduce the proportion of children infested with head lice.

OBJECTIVES

To evaluate the knowledge of physicians in Israel on the biology and epidemiology of lice, as well as their experience with infested individuals and their preferences for diagnosis, prophylaxis and control.

METHODS

An anonymous questionnaire with 37 questions was used. The first 20 questions addressed the general knowledge of physicians on lice biology and control, while the remaining 17 questions were related to their personal experience with lice and louse treatment.

RESULTS

Out of 273 physicians interviewed 66.8% had good knowledge of lice, while the remaining 33.2% had some knowledge on lice. The difference between the groups of physicians with medium and good knowledge on lice was borderline significant (P=0.0722), with the dermatologists borderline significantly less knowledgeable than the rest (P=0.0765). Significant differences were found between those physicians with 4-6 or 11-20 years of professional experience and the remaining groups (twice P<0.001). Although the percentage of female physicians who had a good knowledge on louse biology and control was higher than male physicians (39.4% and 29.4%, respectively), the differences were borderline significant (P=0.09). Pediatricians and dermatologists examined significantly more children than family physicians and general practitioners (P <0.001).

CONCLUSIONS

The results of this study suggest that healthcare professionals' knowledge is of paramount importance for the correct diagnosis and control of head louse infestations.

Heritability of resistance to infestation with the body louse, Bovicola ovis, in Romney sheep bred for differences in resistance or resilience to gastro-intestinal nematode parasites

The inheritance of resistance to louse infestation and the related allergic skin disease, cockle, was examined in Romney lambs. The lambs used in the study were the 2001- and 2004-born progeny of four experimental breeding lines ("Resistant", "Susceptible", "Resilient" and "Control") developed as part of a long-term study of the genetics of host resistance (maintenance of low faecal egg count (FEC) under nematode challenge) or resilience (maintenance of health and productivity under nematode challenge irrespective of FEC) to nematode parasites in sheep. Between 13 and 22 progeny (equally distributed between males and females, where possible) from each of five sires in each line were selected each year for this trial. All lambs (n=701) were examined for lice (Bovicola ovis) before artificial infestation; in 2001 the lambs were free of natural infestation, whilst in 2004 naturally acquired infestation was evident. In November 2001 and May 2002, approximately 60 B. ovis were transferred to each lamb, followed by monitoring at approximately 2-monthly intervals until August 2002. Similar procedures, but with fewer monitoring times, were repeated on the 2004 lambs. Overall, lambs in the Control line were significantly more susceptible to louse infestation and cockle compared with those in the other three lines (P<0.001). Least squares-means (SEM) of log-transformed louse score for the control, resistant, susceptible and resilient lines, respectively, were 2.178 (0.045), 1.499 (0.050), 1.618 (0.050) and 1.587 (0.044), and for cockle score were 1.36 (0.05), 0.76 (0.05), 0.95 (0.05) and 0.78 (0.05). From all progeny together, the heritability of log-transformed louse score was 0.22 (Standard Error (SE) 0.06) in autumn and 0.34 (SE 0.08) in winter, with a value of 0.44 (SE 0.09) when these data were combined. These estimates were similar to those obtained for resistance to gastro-intestinal nematodes in these breeding lines, using log-transformed FECs. Heritability estimates for cockle score in autumn, winter and when combined were 0.06 (SE 0.04), 0.45 (SE 0.09) and 0.40 (SE 0.09), respectively. The genetic correlations of mean log-transformed louse score with mean cockle score and levels of two different louse antigens in wool were, respectively, 0.97 (SE 0.04), 0.96 (SE 0.08) and 0.95 (SE 0.09). However, there was no significant genetic correlation between louse scores and FEC. These results suggest that selective breeding would be effective in reducing louse infestation and cockle in sheep, but that differences in louse burdens were not related to differences in nematode burdens as indicated by FECs.

In-vitro pediculicidal activity of Hedychium spicatum essential oil

The essential oil extracted from rhizomes of Hedychium spicatum was evaluated for in-vitro pediculicidal activity. At 5%, 2% and 1% concentration the essential oil showed more significant activity than 1% permethrin based product.

Overcoming health inequalities by using the Bug Busting 'whole-school approach' to eradicate head lice

AIMS AND OBJECTIVES

The aim of this paper was to illustrate the socially inclusive nature of the Bug Busting 'whole-school approach' to head louse eradication.

BACKGROUND

In the UK, Belgium and Denmark, persistent head lice in families of all socio-economic status (SES) is a problem. Since 1995 in the UK and 1998 elsewhere, an educational programme intended to teach families how to detect and treat head lice by using the Bug Busting wet combing method has been organized in some areas. Local schools lead this community strategy for prevention, known as a 'whole-school approach' (UK).

DESIGN AND METHODS

We describe five studies applying the Bug Busting approach, four set in districts where some disadvantaged families live (UK and Belgium) and a fifth set in Denmark. Feasibility and consumer satisfaction are examined. One UK study analyses data on area prescribing for head lice and the impact in a deprived locality of raising the profile of Bug Busting.

RESULTS

We find parental education in Bug Busting enables families of all SES to participate in a 'whole-school approach' to head lice. Best results are obtained when each family has a Bug Buster Kit. This provides all the combs necessary with full instructions on their use with ordinary shampoo and conditioner to detect lice, eradicate an infestation mechanically, or to check the success of any treatment. In the UK, the promotion of the Bug Busting approach is reducing primary care expenditure on treatment for head lice and professional time spent with worried parents. As a result, healthcare providers can give time to the few families who require one-to-one guidance.

RELEVANCE TO CLINICAL PRACTICE

Incorporation of the Bug Busting approach to head lice into clinical practice in school communities contributes to sustainable control whilst overcoming health inequalities in participating families.

Does dimeticone clear head lice?

Head lice infestation is common and mainly affects children of primary school age. Treatments include licensed topical preparations containing conventional chemical insecticides and medical devices. Each of these fail to eradicate head lice in some patients and resistance is a problem with chemical insecticides. Dimeticone 4% lotion (Hedrin - Thornton & Ross) is a new treatment licensed "for the eradication of head lice infestations". Here we consider its place in the context of other options.

WITHDRAWN: Interventions for treating headlice

BACKGROUND

Infection with head lice is a widespread condition in developed and developing countries. Infection occurs most commonly in children, but also affects adults. If left untreated the condition can become intensely irritating and skin infections may occur if the bites are scratched.

OBJECTIVES

The aim of this review was to assess the effects of interventions for head lice.

SEARCH STRATEGY

Cochrane Infectious Diseases Group specialized trials register (July 2002); The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2002); MEDLINE and TOXLINE (1966 to July 2002); EMBASE (1980 to May 2002); LILACS (July 2002); Science Citation Index (1981 to July 2002); BIOSIS (1985 to July 2002); reference lists of relevant articles; pharmaceutical companies producing pediculicides (published and unpublished trials); UK and US Regulatory Authorities.

SELECTION CRITERIA

Randomised trials (published and unpublished) or trials using alternate allocation were sought which compared pediculicides with the same and different formulations of other pediculicides, and pediculicides with physical methods.

DATA COLLECTION AND ANALYSIS

Of the 71 identified studies, only four met the inclusion criteria. Two reviewers independently assessed trial quality. One reviewer extracted the data.

MAIN RESULTS

We found no evidence that any one pediculicide has greater effect than another. The two studies comparing malathion and permethrin with their respective vehicles showed a higher cure rate for the active ingredient than the vehicle. Another study comparing synergised pyrethrins with permethrin showed their effects to be equivalent. A comparative trial of malathion lotion vs combing, showed combing to be ineffective for the cureative treatment of head lice infection. Adverse effects were reported in a number of trials and were all minor, although reporting quality varied between trials.

AUTHORS' CONCLUSIONS

Permethrin, synergised pyrethrin and malathion were effective in the treatment of head lice. However, the emergence of drug resistance since these trials were conducted means there is no direct contemporary evidence of the comparative effectiveness of these products. The 'best' choice will now depend on local resistance patterns. Physical treatment methods(BugBusting) were shown ot be ineffective to treat head lice. No evidence exists regarding other chemical control methods such as the use of herbal treatments, when used in the curative treatment of head lice. Future trials should take into account the methodological recommendations that arise from this review.