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.     

Infestation status of head louse and treatment with lindane shampoo in children of primary school and kindergarten in Chinju-shi, Kyongsangnam-do, Korea

The infestation status of head louse among children attending primary schools and kindergartens in Chinju-shi, Kyongsangnam-do, Korea, was investigated between June and July 1999. Out of 2,288 children examined, 3.9% of boys (48/1,242) and 23.5% of girls (246/1,046) were infested with nits or adult/nymphs of lice. The effectiveness of lindane shampoo (1% gamma benzene hexachloride solution) was evaluated after one or two time applications to all the children infested. The negative conversion rate of pediculosis was 93.5%. Effective control measures are needed to control and prevent such ectoparasite infestation amongst children.     

Treatment of head louse infestation with 4% dimeticone lotion: randomised controlled equivalence trial

Objective To evaluate the efficacy and safety of 4% dimeticone lotion for treatment of head louse infestation.Design Randomised controlled equivalence trial.Setting Community, with home visits.Participants 214 young people aged 4 to 18 years and 39 adults with active head louse infestation.Interventions Two applications seven days apart of either 4.0% dimeticone lotion, applied for eight hours or overnight, or 0.5% phenothrin liquid, applied for 12 hours or overnight.Outcome measures Cure of infestation (no evidence of head lice after second treatment) or reinfestation after cure.Results Cure or reinfestation after cure occurred in 89 of 127 (70%) participants treated with dimeticone and 94 of 125 (75%) treated with phenothrin (difference -5%, 95% confidence interval -16% to 6%). Per protocol analysis showed that 84 of 121 (69%) participants were cured with dimeticone and 90 of 116 (78%) were cured with phenothrin. Irritant reactions occurred significantly less with dimeticone (3/127, 2%) than with phenothrin (11/125, 9%; difference -6%, -12% to -1%). Per protocol this was 3 of 121 (3%) participants treated with dimeticone and 10 of 116 (9%) treated with phenothrin (difference -6%, -12% to -0.3%).Conclusion Dimeticone lotion cures head louse infestation. Dimeticone seems less irritant than existing treatments and has a physical action on lice that should not be affected by resistance to neurotoxic insecticides.     

A survey on head lice infestation in Korea (2001) and the therapeutic efficacy of oral trimethoprim/sulfamethoxazole adding to lindane shampoo

Total of 7,495 children including 3,908 boys and 3,587 girls from a kindergarten and 15 primary schools were examined for head lice infestation (HLI). The overall prevalence of HLI in this study was found to be 5.8%. Head lice were much more commonly detected in girls than in boys with prevalence of 11.2% and 0.9%, respectively. Sixty-nine children with HLI were treated with 1% lindane shampoo alone (group 1), and 45 children with HLI were treated with 1% lindane shampoo and oral trimethoprim/sulfamethoxazole (group 2), and follow-up visits were conducted 2 and 4 weeks later. The children who still had HLI 2 weeks after the primary treatment were treated again. At the 2-week follow-up visit, the treatment success rates of groups 1 and 2 were 76.8% and 86.7%, respectively, and at the 4-week follow-up visit, the rates were 91.3% and 97.8%, respectively. No statistically significant synergistic effect was observed for the combination of a 1% lindane shampoo and oral trimethoprim/sulfamethoxazole.     

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.     

Randomised, controlled, assessor blind trial comparing 4% dimeticone lotion with 0.5% malathion liquid for head louse infestation

Background

Malathion 0.5% has been the most prescribed pediculicide in the United Kingdom for around 10 years, and is widely used in Europe and North America. Anecdotal reports suggest malathion treatments are less effective than formerly, but this has not been confirmed clinically. This study was designed to determine whether malathion is still effective and if 4% dimeticone lotion is a more effective treatment for head louse infestation.

Methodology/Principal Findings

We designed this study as an assessor blinded, randomised, controlled, parallel group trial involving 58 children and 15 adults with active head louse infestation. Each participant received two applications 7 days apart of either 4% dimeticone lotion, applied for 8 hours or overnight, or 0.5% malathion liquid applied for 12 hours or overnight. All treatment and check-up visits were conducted in participants'' homes. Cure of infestation was defined as no evidence of head lice after the second treatment. Some people were found free from lice but later reinfested. Worst case, intention to treat, analysis found dimeticone was significantly more effective than malathion, with 30/43 (69.8%) participants cured using dimeticone compared with 10/30 (33.3%) using malathion (p<0.01, difference 36.4%, 95% confidence interval 14.7% to 58.2%). Per protocol analysis showed cure rates of 30/39 (76.9%) and 10/29 (34.5%) respectively. Irritant reactions were observed in only two participants, both treated with malathion.

Conclusions/Significance

We concluded that, although malathion liquid is still effective for some people, dimeticone lotion offers a significantly more effective alternative treatment for most people.

Trial Registration

Controlled-Trials.com ISRCTN47755726     

Comparative trial of endocrine versus cytotoxic treatment in advanced breast cancer.

Ninety-two women with advanced breast cancer were allocated at random to receive either cytotoxic or endocrine treatment. Out of 45 women included in the cytotoxic treatment group, 22 (49%) achieved complete or partial remission of their disease, whereas of the 47 included in the endocrine treatment group, only 10 (21%) achieved such remission. Significantly longer survival times in the cytotoxic treatment group were most apparent among premenopausal women, 75% of such patients responding to cytotoxic drugs (median survival 46 weeks) compared with only 11% benefiting from ovarian ablation (median survival 12 weeks). In postmenopausal women with predominantly soft-tissue disease, however, additive hormonal treatment with tamoxifen produced remission rates and survival times equivalent to those produced by cytotoxic drugs.     

Evidence from double infestations for the specific status of human head lice and body lice (Anoplura)

Abstract Samples of head lice and body lice obtained from Ethiopians suffering from double infestations were mounted onto microscope slides and measured. The mean length of body lice (♀ 4.4mm; ♂ 3.8mm) was greater than that of head lice (♀ 3.5 mm; ♂ 2.9mm), but the best discriminant was the length of the tibia of the middle leg (♀ 425/296 μ♂421/291 μ). No intermediate specimens were found in these double infestations, although intermediates can can be produced experimentally by cross-mating. Since populations of head lice and body lice remain distinct it is concluded that they represent two distinct species, Pediculus capitis De Geer and P. humanus Linneaus.     

Growth of asthmatic children during treatment with budesonide: a double blind trial.

OBJECTIVE--To determine whether the inhaled glucocorticosteroid budesonide has any adverse effect on short term linear growth in children with mild asthma. SETTING--Outpatient clinic in secondary referral centre. PATIENTS--15 children aged 6-13 years with normal statural growth velocity during the previous year, no signs of puberty, and no use of systemic or topical steroids in the two months before the study. DESIGN OF INTERVENTIONS--Double blind, randomised crossover trial with two active periods in which budesonide was given in divided daily doses of 200 micrograms and 800 micrograms. During run in and two washout periods placebo was given. After the second washout period the children received open treatment with 400 micrograms budesonide daily. All periods were of 18 days'' duration. MAIN OUTCOME MEASURE--Growth of the lower leg as measured twice a week by knemometry. RESULTS--Mean growth velocity of the lower leg was 0.63 mm/week during run in and during washout 0.64 mm/week. Budesonide treatment was associated with a significant dose related reduction of growth velocity: the mean reduction in growth velocity during treatment was 0.11 (95% confidence interval -0.15 0.36 (0.13 to 0.59) mm/week with 800 micrograms budesonide (p less than 0.05; Page''s test). During treatment with 400 micrograms budesonide a reduction of 0.17 (-0.10 to 0.45) mm/week was found. CONCLUSIONS--Treatment with inhaled budesonide is associated with a dose related suppression of short term linear growth in children with mild asthma.     

Comparative body size relationships in pocket gophers and their chewing lice

In this paper, we use the method of independent contrasts to study body size relationships between pocket gophers and their chewing lice, a host-parasite system in which both host and parasite phylogcnies are well studied. The evolution of body size of chewing lice appears to be dependent only on the body size of their hosts, which confirms the 1991 findings of Harvey and Keymer. We show that there is a positive relationship between body size and hair-shaft diameter in pocket gophers, and that there is also a positive relationship between body size and head-groove width in chewing lice. Finally, we show a positive relationship between gopher hair-shaft diameter and louse head-groove width. We postulate that changes in body size of chewing lice are driven by a mechanical relationship between the parasite's head-groove dimension and the diameter of the hairs of its host. Louse species living"on larger host species may be larger simply because their hosts have thicker hairs, which requires that the lice have a wider head groove. Our study of gopher hair-shaft diameter and louse head-groove dimensions suggest that there is a 'lock-and-key' relationship between these two anatomical features.     

Severe head lice infestation in an Andean mummy of Arica, Chile

Pediculus humanus capitis is an ancient human parasite, probably inherited from pre-hominid times. Infestation appears as a recurrent health problem throughout history, including in pre-Columbian populations. Here, we describe and discuss the occurrence of pre-Columbian pediculosis in the Andean region of the Atacama Desert. Using a light microscope and scanning electron microscopy, we studied a highly infested Maitas Chiribaya mummy from Arica in northern Chile dating to 670-990 calibrated years A.D. The scalp and hair of the mummy were almost completely covered by nits and adult head lice. Low- and high-vacuum scanning electron microscopy revealed a well-preserved morphology of the eggs. In addition, the excellent preservation of the nearly 1,000-yr-old adult head lice allowed us to observe and characterize the head, antennae, thorax, abdomen, and legs. Leg segmentation, abdominal spiracles, and sexual dimorphism also were clearly observed. The preservation of the ectoparasites allowed us to examine the micromorphology using scanning electron microscopy; the opercula, aeropyles, and spiracles were clearly visible. This case study provides strong evidence that head lice were a common nuisance for Andean farmers and herders. Head lice are transmitted by direct head-to-head contact; thus, this ancient farmer and herder was potentially infesting other people. The present study contributes to the body of research focusing on lice in ancient populations.     

What's in a name: the taxonomic status of human head and body lice

Human head lice (Anoplura: Pediculidae: Pediculus) are pandemic, parasitizing countless school children worldwide due to the evolution of insecticide resistance, and human body (clothing) lice are responsible for the deaths of millions as a result of vectoring several deadly bacterial pathogens. Despite the obvious impact these lice have had on their human hosts, it is unclear whether head and body lice represent two morphological forms of a single species or two distinct species. To assess the taxonomic status of head and body lice, we provide a synthesis of publicly available molecular data in GenBank, and we compare phylogenetic and population genetic methods using the most diverse geographic and molecular sampling presently available. Our analyses find reticulated networks, gene flow, and a lack of reciprocal monophyly, all of which indicate that head and body lice do not represent genetically distinct evolutionary units. Based on these findings, as well as inconsistencies of morphological, behavioral, and ecological variability between head and body lice, we contend that no known species concept would recognize these louse morphotypes as separate species. We recommend recognizing head and body lice as morphotypes of a single species, Pediculus humanus, until compelling new data and analyses (preferably analyses of fast evolving nuclear markers in a coalescent framework) indicate otherwise.