Head lice diagnosed in general practice in the West Midlands between 1993 and 2000: a survey using the General Practice Research Database

The potential of the General Practice Research Database (GPRD) for communicable disease surveillance was explored using head lice as an example. All diagnoses of head lice and prescriptions for parasiticidal agents from 1993 to 2000 in the West Midlands were analysed. Diagnoses reached a peak of 28.2 per 1,000 patient years at risk and total prescriptions reached a peak of 27.1 per 1,000 patient years at risk in 1997. Malathion and permethrin were prescribed most often. The proportion of further parasiticidal prescriptions issued within 30 days of the initial prescription increased to a peak of 11.5% of prescriptions in 1997. The ratio of the same:different further prescriptions changed during the study period, reaching a high of 5:1 in 2000. These trends are mirrored by the Royal College of General Practitioners (RCGP) Weekly Returns Service and Prescribing Analysis and Cost (PACT) data. Use of GPRD provides additional insights into patient data, particularly on prescribing, that would not be available from other sources.

The knowledge of healthcare professionals with regard to the treatment and prevention of head lice

This study examined the knowledge and practice of healthcare professionals regarding the prevention and treatment of head lice 18 months after dissemination of local guidelines. A self-administered postal questionnaire was sent to all primary healthcare professionals (general practitioners and practice nurses), community healthcare professionals (community paediatricians, health visitors and school nurses) and pharmacists in South Staffordshire health district, UK. The overall response rate was 48% (range 24-63%). Compared to other groups: community healthcare professionals were more likely to refer to the guidelines and have adequate knowledge of treatment and prevention; pharmacists were least likely to refer to the guidelines; and primary healthcare professionals were most likely to have poor knowledge about prevention and treatment. Overall, healthcare professionals' knowledge regarding prevention methods was significantly better than their knowledge of treatment methods (63% vs. 5%, P <0.00001). In conclusion, the results of this study suggest that healthcare professionals' knowledge of control methods for head lice varies widely and is sub-optimal and may contribute to ineffective head lice control.

Development of a paw paw herbal shampoo for the removal of head lice

The development and clinical testing of an herbal lice removal shampoo, containing a standardized extract of paw paw, thymol, and tea tree oil, are described. All of these ingredients were selected for their ability to deplete adenosine triphosphate (ATP) levels and, thus, prevent ATP-dependent pesticide resistance. Optimum concentrations of the ingredients, treatment times, and dosing schedules were established through in vitro tests with head lice. In addition to pilot studies involving 21 participants, a final clinical trial, using the optimum shampoo formulation in 16 participants, demonstrated 100% effectiveness in removing head lice and nits.

Head louse and other common infections in schools: head teachers' use of an information pack

A descriptive study examined head teachers' use of an information pack about common childhood infections and its usefulness, particularly for head louse infection. The survey covered all 122 schools in one borough in the North West of England. Overall response was 73% and 83.3% of head teachers considered the pack helpful for teachers and parents. The study highlights schools' wish for information and help with common infections, especially head louse infections, from the public health and community health services. The authors recommend providing such information regularly each term or year for teachers and parents, putting head louse infection in context with other common childhood infections. Regular education sessions are recommended for head teachers and community health professionals involved with head louse infections. These measures should help ensure a consistent, evidence-based and up-to-date approach.

Head lice

Head lice infestation is associated with little morbidity but causes a high level of anxiety among parents of school-aged children. This statement attempts to clarify issues of diagnosis and treatment of head lice and makes recommendations for dealing with head lice in the school setting.

Head lice are not found on floors in primary school classrooms

BACKGROUND

The control of head lice is frequently based on perceptions rather than evidence, as illustrated by the belief that vacuuming carpets is an essential component of treating head lice, and the less common practice of application of insecticides to floors as an adjunct to head lice treatment.

OBJECTIVE

To 1) evaluate the importance of floors as a source of infection for head lice in primary schools to provide evidence on which to base decisions about the need to treat floors; 2) determine the prevalence of active pediculosis and average intensity of infection in primary school children in Townsville, north Queensland.

METHODS

In Townsville, north Queensland, we examined preschool and primary classroom floors for lice by using a filter on a vacuum cleaner when the children were absent from the rooms. Active pediculosis was treated, head lice were collected and counted.

RESULTS

Of the 2,230 children examined from 118 classrooms, 466 had head lice, a prevalence of 20.9%. A total of 14,033 lice were collected from these children to give an average intensity of infection of 30.1 (95% CI 21.9-38.3) lice per infected child and 129.9 (95% CI 90.7-169.2) lice per infected class. Of the 118 classrooms, 108 (91.5%) had at least one child with active pediculosis. No lice were recovered from the classroom floors.

CONCLUSION

Classroom floors are not a risk in the transmission of head lice and no special anti-louse measures are required.

Cypermethrin induces glutathione S-transferase activity in the shore crab, Carcinus maenas

Cypermethrin is a synthetic pyrethroid that is particularly toxic to crustacea. It is therefore applied as a chemotherapeutant in the salmonid aquaculture industry for the treatment of sea lice infestations. After use, cypermethrin is released directly into the marine environment, to be diluted by fresh seawater. The shore crab, Carcinus maenas is found in the vicinity of fish farms, and may come into contact with released cypermethrin. The detoxification enzyme, glutathione S-transferase (GST) has been implicated in cypermethrin metabolism in terrestrial arthropods, but this has not yet been demonstrated in crustacea. In this paper we investigate the response of GST activity in Carcinus to cypermethrin exposure, and also the time course of the induction process. GST activity is significantly increased in Carcinus exposed to nominal concentrations of 50 and 500 ng/l of water-borne cypermethrin. Carcinus demonstrate a significant elevation in GST activity following intra-cephalothoracic injection with 10 ng of cypermethrin. GST activity returns to basal levels after 36 h. The potential application of GST activity in Carcinus as a biomarker of cypermethrin exposure is discussed.

Evaluation of the efficacy of fipronil formulations in the treatment and control of biting lice, Trichodectes canis (De Geer, 1778) on dogs

The efficacy of FRONTLINE SPRAY (0.25% (w/v) fipronil), FRONTLINE SPOT-ON FOR DOGS (10% (w/v) fipronil) and FRONTLINE PLUS FOR DOGS (10% (w/v) fipronil and 9% (S)-methoprene) against the biting louse Trichodectes canis on dogs was confirmed under laboratory conditions. A field study evaluated the efficacy of a single topical application of FRONTLINE SPRAY and FRONTLINE SPOT-ON against the parasite on dogs. A total of 48 dogs of mixed breeds, both sexes, aged 2 months-7 years and weighing 1.8-37.0kg were used. The animals were either experimentally (laboratory study) or naturally (field study) infested with lice. Dogs were housed individually in order to prevent contact between animals. In the laboratory study, animals were allocated based on pre-treatment louse counts from 38 hair coat-partings per animal. Dogs were randomly assigned to the four treatment groups: (1) untreated control; (2) FRONTLINE SPRAY, at 6ml/kg; (3) FRONTLINE SPOT-ON as per label and (4) FRONTLINE PLUS as per label. Dogs in treatment groups 2-4 were treated twice topically on Days 0 and 28. The number of live lice in the 38 hair coat-partings per animal were counted on Days 2, 7 and weekly to Day 63. In addition, a whole body comb count was performed on Day 63. No live T. canis were found on dogs treated with FRONTLINE formulations at any post-treatment examination. The difference from controls was significant (P<0.01) for each product at each examination. Based on the whole body comb count at Day 63, the efficacy of each product was determined to be 100%. In the field study, dogs were allocated in strict order of presentation. Dogs were randomly allocated to one of the three treatment groups: (1) BOLFO collar (propoxur); (2) FRONTLINE SPRAY, at 6ml/kg and (3) FRONTLINE SPOT-ON as per label. Dogs were treated once topically on Day 0. The number of live lice was determined by whole body searches on Days 0 (pre-treatment), 2, 28 and 42. Louse counts of dogs treated with either FRONTLINE SPRAY, or FRONTLINE SPOT-ON were not different than those of dogs receiving the propoxur collar. The efficacy was determined to be >98% on Day 2 and, 100% on Days 28 and 42 in all treatment groups. The results of these studies demonstrate that fipronil in topical formulations is effective for treatment and control of biting lice (T. canis) infestations on dogs.

Wet Combing for Head Lice: Feasibility in Mass Screening, Treatment Preference and Outcome

There is no scientific consensus on the best way to control head louse infestation in schoolchildren. A study was conducted to test the feasibility and acceptability of a screening campaign by wet combing and a community approach to head-louse control with home visits, and to explore parents’ treatment preferences and treatment outcomes. A non-controlled intervention (advice on treatment options offered to all positive children) was nested within an epidemiological prevalence study. All children in three primary schools in Ghent, Belgium, were invited to take part in screening by wet combing (n=677, 3–11 years). Positive children were offered structural treatment advice, a home visit on day 7, and a check by wet combing on day 14.

83% of the children were screened. The prevalence of active infestation (living moving lice) was 13.0% in school 1 and 19.5% in school 3. In school 2, prevalence of signs of active and past infestation was 40.7%. A home visit was made to 58% of the positive children. 85% of the positive children were screened again on day 14. Wet combing was the most widely used treatment, followed by chemical treatment and a combination of the two. In school 1 and 3 51% were cured, and in school 2 24% became nit-free. A wet combing screening campaign and a community-oriented approach to head-louse control is feasible though resource-intensive. The prevalence of head lice was high and the cure rate was low, with either topical treatments or wet combing.

Persistent activity of moxidectin pour-on and injectable against sucking and biting louse infestations of cattle

To evaluate the persistent activity of pour-on and injectable moxidectin against natural challenge by sucking (predominantly Linognathus vituli) and chewing (Bovicola bovis) cattle lice, 96 mixed-breed calves that had been treated to remove all lice were blocked by body weight and randomly allocated to three treatments: untreated control, moxidectin at 500 microg/kg by topical application and moxidectin at 200 microg/kg by subcutaneous injection. Twelve pens were blocked into groups of four and randomly allocated to four challenge times: 14, 21, 28 and 35 days post-treatment. Treatment groups were assigned to challenge pens randomly. Two donor calves, with demonstrated infestations of both sucking and chewing lice, were introduced into each pen containing eight principal calves at the start of each challenge time. Donors remained in the challenge pen for 7 days. Principal calves were examined for lice, 7, 14, 21 and 28 days after donor removal using a standardized hair-parting technique. Moxidectin injectable prevented re-infestation with L. vituli for up to 42 days, but did not provide persistent activity against B. bovis longer than 35 days post-treatment. Moxidectin pour-on demonstrated persistent activity against both B. bovis and L. vituli for 42 days.

Persistent efficacy of doramectin topical solution against induced infestations of Bovicola bovis and Solenopotes capillatus

A study was conducted in two locations, Wyoming and Wisconsin, USA, to evaluate the persistent efficacy of doramectin topical solution at a dose rate of 500 microg/kg body weight against artificially induced infestations of Bovicola bovis and Solenopotes capillatus on cattle. At each location, lice-free beef calves were individually housed and randomly allocated to treatment. Both B. bovis and S. capillatus were transferred from untreated donor animals to doramectin-treated cattle at the end of 35, 63, 91 or 126 day post-treatment periods. Cattle treated with a saline pour-on served as the control. Based on the geometric means of lice counts 2 weeks following transfer, the persistent efficacy of a single treatment with doramectin topical solution against induced infestations of B. bovis was 100.0, 100.0, 99.5, and 100.0% at post-treatment days of 35, 63, 91, and 126, respectively. Persistent efficacy against induced infestations of S. capillatus, for the same intervals, were 100.0, 94.9, 86.3, and 74.9%.

Primary grade teachers' knowledge and perceptions of head lice

This study examined primary grade teachers' knowledge of head lice, perceived self-efficacy in dealing with head lice, and preferred resources of additional information on head lice. Survey data from a three-wave mailing (M = 292; 60%) found that teachers needed more knowledge regarding head lice and were significantly more knowledgeable as teaching experience increased. A plurality (46%) had high efficacy expectations scores regarding their ability to control the spread of head lice. Most (71%) primary teachers reported they received most of their head lice information from school nurses. Most (63%) said they would like more information on how to prevent head lice infestation, and they wanted the information in the form of videotapes (68%) and brochures (51%). Only 23% provided yearly instruction regarding head lice.

Head lice infestation: bug busting vs. traditional treatment

The two main methods of managing head lice infestation in the UK are head lice lotions and bug busting; there is no conclusive evidence as to which of these methods is most effective. The aim of this study was to compare the effectiveness of the bug busting method with lotion. A pilot study in the form of a randomized controlled trial involving two semi-rural general practices was used. Thirty children aged 4-16 years were randomly assigned to two intervention groups. After initial dry combing to detect the presence of head lice, one group was treated with phenothrin lotion. The bug busting group received combing using special combs provided in the bug busting pack and hair conditioner. The main outcome measure was the number of adult live lice and nymphs at day 14. On day 14 in the bug busting group, total eradication of head lice had occurred in eight children; in the lotion group, total eradication had occurred in two children (P=0.052); number needed to treat 2.5 (95% CI: 2.19-2.81). These results suggest that bug busting performed by nurses in a controlled situation is an effective method of managing head lice infestation.

Ectoparasite control in small ruminants

Ectoparasites are a common problem in small ruminants of North America. Management of ectoparasites in small ruminants can be challenging for producers and veterinarians. It is important for the veterinarian to make an accurate diagnosis of the type of ectoparasite that is infesting the animal, then to develop a plan that most effectively and economically controls the ectoparasite. Effective and economic control of an ectoparasite infestation begins with an understanding of the ectoparasite's life cycle and how that life cycle affects the animal. It should be noted that climate and geographical area can affect the life cycle of specific ectoparasites, so it is important for veterinarians to educate themselves about their specific environment. Once the life cycle has been addressed, then the veterinarian should decide which intervention will provide the best control. Intervention possibilities may range from insecticides to environmental management or a combination of several methods. The veterinarian should provide the producer with realistic goals that define specific limitations of ectoparasite control.

Towards the eradication of head lice: literature review and research agenda

Head lice infestation is a public health issue. In the effort to compile an evidence-base about the physiology, detection, treatment, effects and management strategies of head lice infestations we reviewed current literature. This literature signalled significant evidence gaps and these gaps provide incentives for further research. Our conclusions from the literature are that parents of children are responsible for head lice detection and treatment but have varying access to advice about how best to treat this condition. Concern is exacerbated by misconceptions surrounding the circumstances of infestation. Head lice are a low priority for health professionals in Australia, whereas parents and teachers believe the problem necessitates greater attention. It is important to provide a unified evidence-based approach to good information. It is timely for health care professionals to re-examine and prioritize this public health issue. They should research and work collaboratively towards the eradication of head lice.

Lice, nits, and school policy

BACKGROUND

The epidemiology of head lice infestation is poorly understood. Many schools treat all children with nits as though they are contagious. Children with nits but no lice are often removed from school until they are treated and all visible nits are removed.

OBJECTIVE

To investigate the probability that children with nits alone will become infested with lice.

DESIGNS

Prospective cohort study.

SETTING

Two metropolitan Atlanta elementary schools.

PARTICIPANTS

A total of 1729 children were screened for head lice. Twenty-eight children (1.6%) had lice, whereas 63 (3.6%) had nits without lice. Fifty of the 63 children (79%) with nits alone completed follow-up.

OUTCOME MEASURE

Conversion (ie, becoming infested with lice) within 14 days after initial screening.

RESULTS

Nine of 50 children (18.0%) followed for nits alone converted. Although children who converted did not have significantly more nits than did nonconverters, having nits near the scalp was a risk factor for conversion. Seven of 22 children (31.8%) with >/=5 nits within one fourth inch of the scalp converted, compared with 2 of 28 children (7.1%) with fewer (relative risk: 4.45; 95% confidence interval: 1.03-19.35). This risk remained statistically significant after separately stratifying for sex, recent treatment, and total number of nits.

CONCLUSIONS

Although having >/=5 nits within one fourth inch of the scalp was a risk factor for conversion, most children with nits alone did not become infested. Policies requiring exclusion from school and treatment for all children with nits alone are likely excessive. Instead, these children may benefit from repeated examination to exclude the presence of crawling lice.lice, pediculus, lice infestations, pediatrics, school.