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.