RESUMO
Pediculosis by Pediculus humanus capitis is still an important health issue in school-age students worldwide. Although pediculicidal agents effectively kill head lice, the re-infestation rate is still high. This study was conducted to provide a summary of evidence about the prevalence of pediculosis capitis among school-age students worldwide. Different databases including MEDLINE/PubMed, Scopus, and Web of Science were searched for publications related to pediculosis capitis in school-age students from 1977 to 2020. All peer-reviewed original research articles describing pediculosis capitis among school-age students were included. Statistical heterogeneity of the different years among studies was assessed using the standard chi squared and I2 tests. Due to the significant heterogeneity, a random effect model was adopted to estimate the pooled, continent, and gender-specific prevalence of pediculosis. Two hundred and one papers met the inclusion criteria of this review and entered into the meta-analysis including 1,218,351 individuals. Through a random effect model, the prevalence of pediculosis capitis among school students was estimated as 19% (CI 95% = 0.18-0.20%, I2 = 99.89%). The prevalence of pediculosis capitis among boys was 7% (CI 95% = 0.05-0.10) compared to 19% (CI 95% = 0.15-0.24) in girls. The highest prevalence was in Central and South America (33%, CI 95% = 0.22-0.44, I2 = 99.81%) and the lowest was in Europe (5%, CI 95% = 4-6, I2 = 99.28%). Relatively high pediculosis capitis prevalence among school-age students observed in this study emphasizes the need for implementing screening and prophylaxis tailored to the local context.
Assuntos
Infestações por Piolhos/epidemiologia , Pediculus/crescimento & desenvolvimento , Estudantes/estatística & dados numéricos , Adolescente , Animais , Criança , Europa (Continente)/epidemiologia , Feminino , Humanos , Infestações por Piolhos/tratamento farmacológico , Masculino , Programas de Rastreamento , Prevalência , Saúde Pública , Instituições Acadêmicas , América do Sul/epidemiologiaRESUMO
Lice have been parasitizing humans for at least 10,000 years. Since then, humans have tried to rid themselves of these unpleasant and potentially disease-carrying insects. Despite various plant extracts and chemical compounds being used to combat recurring infestations to this date, several lice populations have developed resistance to some of the abundantly used compounds. This resulted in the development of anti-louse products that physically kill the different lice stages. Today, a widely used group of delousing agents are dimethicones (polydimethylsiloxane PDMS) which function by suffocating the lice. However, many dimethicones and related products are highly flammable which makes them potentially dangerous for treatment. In the present study, we tested the flammability of 22 delousing agents in order to shed some light onto this currently unresolved problem in the product design of pediculicides. Thirteen products were easily ignitable, some even by distant contact with a sparkler.
Assuntos
Dimetilpolisiloxanos/farmacologia , Incêndios , Inseticidas/farmacologia , Infestações por Piolhos/tratamento farmacológico , Pediculus/crescimento & desenvolvimento , Extratos Vegetais/farmacologia , Animais , Vetores de Doenças , HumanosRESUMO
There are no rigorous data on how long eggs of the head louse, Pediculus capitis (Phthiraptera: Pediculidae), take to hatch. Pediculicide users often report reinfestations after apparently successful treatments in the absence of infective contacts. This study aimed to resolve the question of whether some louse eggs hatch after the completion of treatment, thereby giving rise to a new infestation. Data were extracted from the records of lice collected after treatments in 20 clinical intervention trials. All datasets were eliminated except those in which only newly hatched louse nymphs were found prior to the final assessment. This excluded the possibility that new eggs were laid after the first treatment and thus any young lice found must have originated from eggs laid before the start of treatment. This identified 23 of 1895 (1.2%) records with evidence of louse nymphs emerging at 13 days or more after the first treatment, 36 days longer than previous estimates. Current treatment regimens for pediculicides of two applications 710 days apart appear inadequate, which may explain continuing infestation in the community. Therefore, it is suggested that a revised approach using three treatments applied at intervals of 1 week should prevent the survival of any nymphs and their development into a new generation of adults.
Assuntos
Infestações por Piolhos/parasitologia , Pediculus/crescimento & desenvolvimento , Animais , Inseticidas/administração & dosagem , Inseticidas/farmacologia , Infestações por Piolhos/tratamento farmacológico , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Pediculus/efeitos dos fármacos , Estudos Retrospectivos , Dermatoses do Couro Cabeludo/tratamento farmacológico , Dermatoses do Couro Cabeludo/parasitologia , Fatores de TempoRESUMO
Synergists (piperonyl butoxide, MGK-264 (N-octyl bicycloheptene dicarboximide), DEF (S, S, S, tributyl phosphorotrithioate), and diethylmaleate) were used to investigate the metabolic resistance of body lice to permethrin. Instances of the synergistic activity ofpermethrin when combined with enzyme system inhibitors have been identified. The synergic ratios were 3.3 to 52.0 for monooxygenase inhibitors; 5.2 to 7.4 for esterases, and about 4 for glutathione-S-transferases. Since the use of the synergists did not lead to full inhibition of resistance, it was concluded that the lice had also a kdr-like type of resistance.
Assuntos
Inibidores Enzimáticos , Inseticidas , Infestações por Piolhos/parasitologia , Pediculus/enzimologia , Sinergistas de Praguicidas , Animais , Pessoas Mal Alojadas , Humanos , Resistência a Inseticidas/fisiologia , Isoindóis , Maleatos , Norbornanos , Organotiofosfatos , Pediculus/crescimento & desenvolvimento , Permetrina , Butóxido de PiperonilaRESUMO
The activity of insecticides (CK50, CK95 ) from different chemical classes against permethrin-resistant body and head lice was investigated. Having developed resistance to pyrethroids (permethrin, d-phenothrin, cypermethrin, and deltamethrin), the lice remain susceptible to organophosphorus compounds, phenylpyrazoles, neonicotinoids, and avermectins. The susceptibility of lice to the insecticides having a mechanism of action that is different from that of pyrethroids does not depend on the level of their resistance to permethrin.
Assuntos
Inseticidas/farmacologia , Compostos Organofosforados/farmacologia , Pediculus/efeitos dos fármacos , Anabasina/farmacologia , Animais , Relação Dose-Resposta a Droga , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/fisiologia , Ivermectina/análogos & derivados , Ivermectina/farmacologia , Dose Letal Mediana , Nitrilas/farmacologia , Pediculus/crescimento & desenvolvimento , Permetrina/farmacologia , Pirazóis/farmacologia , Piretrinas/farmacologiaRESUMO
Using the in vitro rearing system in conjunction with the hair tuft bioassay, NYDA and NYDA without fragrances formulations (92% wt:wt dimeticones) were 100% ovicidal (0% of treated eggs hatched) after an 8-h exposure of the eggs of the human head louse (Pediculus humanus capitis De Geer) following the manufacturer's instructions. Comparatively, 78 and 66% of eggs similarly exposed hatched after distilled deionized water or Nix (1% permethrin) treatments, respectively. NYDA and NYDA without fragrances formulations were also statistically and substantially more ovicidal than either distilled deionized water or Nix treatments after 10, 30 min, and 1 h exposures. Only the 10 min exposure of eggs to NYDA and NYDA without fragrances formulations resulted in hatched lice that survived to adulthood (5-8% survival). Of the lice that hatched from eggs exposed to NYDA formulations for 10 min, there were no significant differences in the time it took them to become adults, female fecundity or the viability of eggs laid by surviving females. The longevity of adults, however, was reduced after the 10 min treatments of eggs with NYDA and NYDA without fragrances formulations compared with either the distilled deionized water or Nix treatments.
Assuntos
Dimetilpolisiloxanos/administração & dosagem , Óvulo , Pediculus , Animais , Bioensaio , Feminino , Cabelo , Humanos , Larva , Pediculus/crescimento & desenvolvimento , Testes de ToxicidadeRESUMO
BACKGROUND: There are two components to the clinical efficacy of pediculicides: (i) efficacy against the crawling-stages (lousicidal efficacy); and (ii) efficacy against the eggs (ovicidal efficacy). Lousicidal efficacy and ovicidal efficacy are confounded in clinical trials. Here we report on a trial that was specially designed to rank the clinical ovicidal efficacy of pediculicides. Eggs were collected, pre-treatment and post-treatment, from subjects with different types of hair, different coloured hair and hair of different length. METHOD: Subjects with at least 20 live eggs of Pediculus capitis (head lice) were randomised to one of three treatment-groups: a melaleuca oil (commonly called tea tree oil) and lavender oil pediculicide (TTO/LO); a eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO); or a "suffocation" pediculicide. Pre-treatment: 10 to 22 live eggs were taken from the head by cutting the single hair with the live egg attached, before the treatment (total of 1,062 eggs). TREATMENT: The subjects then received a single treatment of one of the three pediculicides, according to the manufacturers' instructions. Post-treatment: 10 to 41 treated live eggs were taken from the head by cutting the single hair with the egg attached (total of 1,183 eggs). Eggs were incubated for 14 days. The proportion of eggs that had hatched after 14 days in the pre-treatment group was compared with the proportion of eggs that hatched in the post-treatment group. The primary outcome measure was % ovicidal efficacy for each of the three pediculicides. RESULTS: 722 subjects were examined for the presence of eggs of head lice. 92 of these subjects were recruited and randomly assigned to: the "suffocation" pediculicide (n = 31); the melaleuca oil and lavender oil pediculicide (n = 31); and the eucalyptus oil and lemon tea tree oil pediculicide (n = 30 subjects). The group treated with eucalyptus oil and lemon tea tree oil had an ovicidal efficacy of 3.3% (SD 16%) whereas the group treated with melaleuca oil and lavender oil had an ovicidal efficacy of 44.4% (SD 23%) and the group treated with the "suffocation" pediculicide had an ovicidal efficacy of 68.3% (SD 38%). CONCLUSION: Ovicidal efficacy varied substantially among treatments, from 3.3% to 68.3%. The "suffocation" pediculicide and the melaleuca oil and lavender oil pediculicide (TTO/LO) were significantly more ovicidal than eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO) (P < 0.0001). Ranking: 1. "Suffocation" pediculicide (68.3% efficacy against eggs); 2. Melaleuca oil and lavender oil (44.4%) pediculicide; 3. Eucalyptus oil and lemon tea tree oil (3.3%) pediculicide. The "suffocation" pediculicide and TTO/LO are also highly efficacious against the crawling-stages. Thus, the "suffocation" pediculicide and TTO/LO should be recommended as first line treatments.
Assuntos
Inseticidas/uso terapêutico , Leptospermum , Infestações por Piolhos/tratamento farmacológico , Melaleuca , Óleos Voláteis/uso terapêutico , Óvulo/efeitos dos fármacos , Pediculus/efeitos dos fármacos , Fitoterapia , Óleos de Plantas/uso terapêutico , Dermatoses do Couro Cabeludo/tratamento farmacológico , Óleo de Melaleuca/uso terapêutico , Acrilatos/administração & dosagem , Acrilatos/farmacologia , Acrilatos/uso terapêutico , Animais , Álcool Benzílico/administração & dosagem , Álcool Benzílico/farmacologia , Álcool Benzílico/uso terapêutico , Criança , Pré-Escolar , Método Duplo-Cego , Combinação de Medicamentos , Etilaminas/administração & dosagem , Etilaminas/farmacologia , Etilaminas/uso terapêutico , Eucalyptus , Óleo de Eucalipto , Hexoses/administração & dosagem , Hexoses/farmacologia , Hexoses/uso terapêutico , Humanos , Inseticidas/administração & dosagem , Inseticidas/farmacologia , Lavandula , Infestações por Piolhos/parasitologia , Óleo Mineral/administração & dosagem , Óleo Mineral/farmacologia , Óleo Mineral/uso terapêutico , Monoterpenos/administração & dosagem , Monoterpenos/farmacologia , Monoterpenos/uso terapêutico , Óleos Voláteis/administração & dosagem , Óleos Voláteis/farmacologia , Óvulo/crescimento & desenvolvimento , Pediculus/crescimento & desenvolvimento , Óleos de Plantas/administração & dosagem , Óleos de Plantas/farmacologia , Polissorbatos/administração & dosagem , Polissorbatos/farmacologia , Polissorbatos/uso terapêutico , Dermatoses do Couro Cabeludo/parasitologia , Óleo de Melaleuca/administração & dosagem , Óleo de Melaleuca/farmacologiaRESUMO
Eggs of the head louse, Pediculus capitis De Geer (Phthiraptera: Pediculidae), are difficult to remove because the female louse fixes them to hairs using a proteinaceous secretion that hardens within seconds. The persistent eggshells are harmless but unsightly and are often mistaken for an active infestation. Combing with a fine comb (nit comb) does not readily remove the eggs or empty eggshells because of the resilience of the fixative and both folk remedies and medical products have claimed to facilitate their removal. Measurement of the force required to initiate sliding of the egg fixative using a slip-peel tester was unable to detect evidence that any of three products which claimed to have egg-loosening properties (Step 2 Nit Removal System, Clear Lice Egg Remover, RID Lice Egg Loosener Gel) had any activity or exerted any effect on the egg fixative beyond the lubricating effects conveyed by water or conventional hair conditioner.
Assuntos
Preparações para Cabelo , Cabelo/parasitologia , Infestações por Piolhos/terapia , Pediculus/crescimento & desenvolvimento , Animais , Feminino , Humanos , HigieneRESUMO
Human body lice (Pediculus humanus) are neglected ectoparasites and pathogen vectors. Difficulties in raising and maintaining colonies of body lice in a laboratory setting remain a barrier to fundamental studies of physiology and vector-pathogen interactions in these insects. Several in vivo and in vitro rearing systems have been previously described and used by multiple research groups. However, these methods suffer from drawbacks that still complicate the rearing of body lice relative to many other commonly studied hematophagous insects. Here, a simplified protocol for raising and maintaining body lice in vitro using the commercially available Hemotek apparatus is described. This protocol draws from published methods for rearing body lice as well as other hematophagous insect species to further reduce labor, time, costs, and regulatory requirements typically associated with keeping human body lice in the laboratory. Using this protocol, the insects consistently fed on commercially available rabbit blood with little mortality, reached adulthood at a high rate, and produced a significant number of viable eggs, resulting in a 4.8-fold increase in population over a period of 40 days. The data suggest that the process described here can propagate modest populations for ongoing laboratory experiments and is a useful alternative to existing methods. The use and further optimization of in vitro rearing systems may facilitate dynamic studies of body lice by a wider range of investigators, enabling new progress in combating lice infestations, and louse-borne infections.
TITLE: Un protocole simplifié pour l'élevage in vitro des poux du corps de l'homme. ABSTRACT: Les poux du corps de l'homme (Pediculus humanus) sont des ectoparasites et des vecteurs de pathogènes négligés. Les difficultés à élever et à maintenir des colonies de poux du corps en laboratoire restent un obstacle aux études fondamentales en physiologie et des interactions vecteur-pathogène chez ces insectes. Plusieurs systèmes d'élevage in vivo et in vitro ont déjà été décrits et utilisés par plusieurs groupes de recherche. Cependant, ces méthodes souffrent d'inconvénients qui compliquent encore l'élevage des poux du corps par rapport à de nombreux autres insectes hématophages couramment étudiés. Ici, un protocole simplifié pour élever et maintenir des poux du corps in vitro en utilisant l'appareil Hemotek, disponible dans le commerce, est décrit. Ce protocole s'inspire des méthodes publiées pour l'élevage des poux du corps ainsi que d'autres espèces d'insectes hématophages pour réduire le travail, le temps, les coûts et les exigences réglementaires généralement associées à la conservation des poux du corps dans le laboratoire. En utilisant ce protocole, les insectes se nourrissent constamment de sang de lapin disponible dans le commerce avec peu de mortalité, atteignent l'âge adulte avec un taux élevé et produisent un nombre important d'Åufs viables, entraînant une augmentation de 4,8 fois de la population sur une période de 40 jours. Les données suggèrent que le processus décrit ici peut propager des populations modestes pour des expériences de laboratoire et est une alternative utile aux méthodes existantes. L'utilisation et l'optimisation des systèmes d'élevage in vitro peuvent faciliter les études dynamiques des poux du corps par un plus large éventail de chercheurs, permettant de nouveaux progrès dans la lutte contre les infestations par les poux et les infections transmises par les poux.
Assuntos
Sangue , Comportamento Alimentar , Infestações por Piolhos/parasitologia , Parasitologia/métodos , Pediculus/crescimento & desenvolvimento , Animais , Feminino , Humanos , Técnicas In Vitro , Estágios do Ciclo de Vida , CoelhosAssuntos
Infestações por Piolhos/diagnóstico , Animais , Humanos , Inseticidas/administração & dosagem , Infestações por Piolhos/parasitologia , Infestações por Piolhos/terapia , Infestações por Piolhos/transmissão , Pediculus/anatomia & histologia , Pediculus/crescimento & desenvolvimento , Prevenção Secundária , Falha de TratamentoRESUMO
The infestation with the human ectoparasite, Pediculus humanus capitis (De Geer), is a common public health problem affecting schoolchildren worldwide. In Chile, the main active ingredients present in the over-the-counter pediculicides contain pyrethroids. Despite the extended use of these products, there is no evidence of the insecticide resistance status of the head lice geographically located in Chile. The most extended resistant mechanism of pyrethroids consists of the target site insensitivity (Kdr) determined by the presence of mutations linked to insecticide-binding sites in the voltage-sensitive sodium channel. T917I is recognized as the main mutation in head lice, and detection is considered to be a biomarker of resistance. The goal of the present study was to detect the presence and distribution of T917I mutation in five geographic locations of Chile. All five geographically selected louse populations had a frequency of pyrethroid resistance genes that ranged from 36 to 77%, and 94.9% of the collected head lice had one or two T917I mutant alleles. Moreover, the frequency of the aggregate resistant alleles was 50.5%. This is the first evidence that head lice in Chile had the mutations commonly associated with the resistance to pyrethroids. Moreover, the overrepresentation of heterozygotes in the studied populations suggests that head lice in Chile are currently under active selective pressure.
Assuntos
Resistência a Inseticidas/genética , Inseticidas/farmacologia , Pediculus/genética , Piretrinas/farmacologia , Alelos , Animais , Chile , Feminino , Proteínas de Insetos/análise , Masculino , Ninfa/efeitos dos fármacos , Ninfa/genética , Pediculus/efeitos dos fármacos , Pediculus/crescimento & desenvolvimento , Canais de Sódio/análiseRESUMO
The presence of Acinetobacter baumannii was demonstrated in body lice, however, little is known about the mechanism of natural lice infection. In 2013 and 2014, cross-sectional one-day studies were therefore performed within two Marseille homeless shelters to assess the presence of A. baumannii DNA on human skin, blood and in body lice collected from the same homeless individuals. All 332 participants completed questionnaires, were examined for dermatologic signs, and provided four skin samples (hair, neck, armpits, and pelvic belt), blood samples and body lice (if any). We developed a new real-time PCR tool targeting the ompA/motB gene for the detection of A. baumannii for all collected samples. Blood culture was also performed. Body lice were found in 24/325 (7.4%) of subjects. We showed a prevalence of A. baumannii DNA skin-carriage in 33/305 (10.8%) of subjects. No difference was found in A. baumannii DNA prevalence according to body sites. A strong association between body lice infestation (OR = 3.07, p = 0.029) and A. baumannii DNA skin-carriage was noted. In lice, A. baumannii DNA was detected in 59/219 arthropods (26.9%). All blood cultures and real-time PCR on blood samples were negative for A. baumannii. Lice probably get infected with A. baumannii while biting through the colonized skin and likely transmit the bacteria in their feces. We found no evidence that lice facilitate the invasion of A. baumannii into the blood stream. Further investigations are needed to compare phenotypic and genotypic features of A. baumannii isolates from human skin and lice from the same individuals.
Assuntos
Infecções por Acinetobacter/epidemiologia , Portador Sadio/epidemiologia , DNA Bacteriano/isolamento & purificação , Pessoas Mal Alojadas , Infestações por Piolhos/complicações , Pele/microbiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Animais , Sangue/microbiologia , Portador Sadio/microbiologia , Estudos Transversais , DNA Bacteriano/genética , França/epidemiologia , Genótipo , Cabelo/microbiologia , Humanos , Pediculus/crescimento & desenvolvimento , PrevalênciaRESUMO
Insecticide resistance in Pediculus humanus capitis De Geer 1778 (Phthiraptera: Pediculidae) from different countries has been well documented in the last years. Otherwise, little research has been reported about insecticide resistance in insect embryos and none in human louse embryos. In this work, we studied insecticide resistance in eggs of three head lice populations whose pyrethroid resistance was shown in adults and nymphs compared with a susceptible laboratory body louse strain. All head louse populations showed high permethrin resistance in eggs. Levels of permethrin resistance (LCRs) assessed in eggs by immersion technique were higher than those previously reported for the corresponding populations of adults by topical application. Comparison of LCR values for different populations showed that there was a direct relationship between the resistance levels assessed in eggs and those in adults. All permethrin-resistant eggs showed high resistance to d-phenothrin and dichloro-diphenyl-trichloroethane (DDT) and low resistance to carbaryl, which is in common with the resistance profile established for adults and nymphs. The results concerning the high resistance to pyrethroid (permethrin and d-phenothrin) and the cross-resistance to DDT and carbaryl detected in head louse eggs and adults suggested similar resistance mechanisms in eggs and adults of head louse populations from adults.
Assuntos
Inseticidas/toxicidade , Óvulo/efeitos dos fármacos , Pediculus/fisiologia , Piretrinas/toxicidade , Animais , Argentina , DDT/toxicidade , Resistência a Medicamentos , Ecossistema , Feminino , Ninfa/efeitos dos fármacos , Pediculus/efeitos dos fármacos , Pediculus/crescimento & desenvolvimentoRESUMO
In Argentina, field populations of the head louse Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae) have developed resistance to permethrin and other pyrethroids. Thus, the aim of this work was the development of a lotion containing essential oils from plants and an alcoholic coadjuvant to improve biological effect. Ethanol + isopropanol (1 + 1 in volume) 50% in water and ethanol 96% were taken as bases for preparation of experimental lotions containing essential oils from plants. We found that experimental lotions containing lavender, peppermint and eucalyptus oils in a 5% composition and the combination of eucalyptus and peppermint in a total concentration of 10%, dissolved in 50% ethanol + isopropanol (1 + 1) in water, showed the best knockdown effect. On the other side, lotion containing peppermint oil and eucalyptus oil (1 + 1) 10%, dissolved in ethanol 96%, showed to be as effective as the best commercial lotion now available in Argentina. Furthermore, addition of 1-dodecanol in all cases increased the effectiveness of all the experimental lotions. This difference is significantly important for 1-dodecanol concentration of 10%, reaching a toxic activity compared to the best commercial lotion available in the market.
Assuntos
Inseticidas/farmacologia , Infestações por Piolhos/parasitologia , Óleos Voláteis/farmacologia , Pediculus/efeitos dos fármacos , Permetrina/farmacologia , Dermatoses do Couro Cabeludo/parasitologia , Animais , Dodecanol/farmacologia , Combinação de Medicamentos , Eucalyptus , Humanos , Técnicas In Vitro , Resistência a Inseticidas , Lavandula , Infestações por Piolhos/tratamento farmacológico , Mentha piperita , Pediculus/crescimento & desenvolvimento , Fitoterapia/métodos , Óleos de Plantas/farmacologia , Dermatoses do Couro Cabeludo/tratamento farmacológicoRESUMO
Head louse infestations are increasing or remain high in most countries. In order to reduce the proportion of children infested with head lice and slow down the emergence of strains of lice resistant to pediculicides, more active involvement of health and educational authorities, as well as parents, is of paramount importance. We suggest that health authorities should introduce more efficient methods for evaluating pediculicides and more stringent regulations for adoption of new anti-louse products. Baseline studies are also essential for new pediculicides. Children should be properly screened, especially in problematic areas. The media should be used to educate parents on louse control. Health providers need to be aware of which anti-louse remedies are demonstrably effective and be capable of assisting families with louse control. Academic institutions should conduct baseline and efficacy studies on pediculicides and other treatment modalities, as well as research on the biology and epidemiology of lice. Parents should regularly inspect their children, treat as necessary, and try to avoid creating stigmas and emotional problems for the child. The pharmaceutical industry should aim to introduce pediculicides based on new chemical compounds, especially natural products. Companies should develop effective and safe repellents and nit removal remedies. General recommendations are given on how to diagnose and treat louse infestations with chemicals, biological agents, and louse combs and how to protect children from infestations. The no-nit policy, based on the persistence of empty egg cases, is not justified and does more harm than good; therefore, we recommend that it be immediately halted.
Assuntos
Infestações por Piolhos/prevenção & controle , Pediculus/crescimento & desenvolvimento , Dermatoses do Couro Cabeludo/prevenção & controle , Animais , Criança , Humanos , Cooperação Internacional , Infestações por Piolhos/diagnóstico , Programas de Rastreamento/métodos , Vigilância da População/métodos , Dermatoses do Couro Cabeludo/diagnósticoRESUMO
Studies were undertaken to determine the ovicidal efficacy of 5,5'-dimethyl-2,2'-bipyridyl (abametapir) against eggs of both human head and body lice. Head lice eggs of different ages (0-2, 3-5, and 6-8-d-old eggs) were exposed to varying concentrations of abametapir in isopropanol and concentration-dependent response relationships established based on egg hatch. One hundred percent of all abametapir-treated eggs failed to hatch at the 0.74 and 0.55% concentrations, whereas 100% of 6-8-d-old head louse eggs failed to hatch only at the 0.74% concentration. The LC50 value for abametapir varied, depending on the age of the head lice eggs, from â¼0.10% recorded for 0-2-d-old eggs and increasing to â¼0.15% for 6-8-d-old eggs. Abametapir was also evaluated once formulated into a lotion referred to as Xeglyze (0.74% abametapir) and serial dilutions made. Ovicidal efficacies were determined against head lice eggs 0-8-d-old. Results indicated 100% ovicidal activity at the 0.74, 0.55, 0.37, and 0.18% concentrations. Additional studies undertaken using body lice eggs also demonstrated that abametapir was 100% ovicidal against eggs of all ages when evaluated at a concentration of 0.37 and 0.55%. Given that ovicidal activity is a critical component of any effective treatment regime for louse control, the data presented in this study clearly demonstrate the ability of abametapir to inhibit hatching of both head and body louse eggs as assessed in vitro.
Assuntos
2,2'-Dipiridil/análogos & derivados , Controle de Insetos , Inseticidas , Pediculus , Animais , Relação Dose-Resposta a Droga , Óvulo/crescimento & desenvolvimento , Pediculus/crescimento & desenvolvimentoRESUMO
Although the head louse, Pediculus humanus capitis De Geer, and body louse, Pediculus humanus humanus L., both have a worldwide distribution, the occurrence of head louse pediculosis appears to be more prevalent in modern societies despite systematic use of various pediculicides. This study tested head lice collected in rural Georgia and body lice collected in Russia for the prevalence of a kdr-biomarker that is associated with permethrin resistance. This study also screened lice for the presence of DNA from Bartonella quintana and Acinetobacter species. The kdr-permethrin resistance biomarker for the T917I mutation was detected by RFLP and PCR in 99.9% of head lice tested from Georgia, whereas only 2.9% of body lice from Russia tested positive for this kdr biomarker. DNA of B. quintana was detected in 10.3% of head lice from Georgia, whereas 84.8% of body lice from Russia tested positive. Acinetobacter DNA was detected in 80.8% (95% CI, 68-89%) of head lice from Georgia and all body lice from Russia tested.
Assuntos
Resistência a Inseticidas , Inseticidas/farmacologia , Pediculus/efeitos dos fármacos , Permetrina/farmacologia , Acinetobacter/isolamento & purificação , Animais , Bartonella quintana/isolamento & purificação , California , Criança , Pré-Escolar , DNA Bacteriano/análise , Feminino , Georgia , Humanos , Infestações por Piolhos/parasitologia , Masculino , Ninfa/efeitos dos fármacos , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Pediculus/genética , Pediculus/crescimento & desenvolvimento , Pediculus/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Federação RussaRESUMO
Epidemic typhus caused by Rickettsia prowazekii is one of the oldest pestilential diseases of humankind. The disease is transmitted to human beings by the body louse Pediculus humanus corporis and is still considered a major threat by public health authorities, despite the efficacy of antibiotics, because poor sanitary conditions are conducive to louse proliferation. Epidemic typhus has accompanied disasters that impact humanity and has arguably determined the outcome of more wars than have soldiers and generals. The detection, identification, and characterization of microorganisms in ancient remains by paleomicrobiology has permitted the diagnosis of past epidemic typhus outbreaks through the detection of R. prowazekii. Various techniques, including microscopy and immunodetection, can be used in paleomicrobiology, but most of the data have been obtained by using PCR-based molecular techniques on dental pulp samples. Paleomicrobiology enabled the identification of the first outbreak of epidemic typhus in the 18th century in the context of a pan-European great war in the city of Douai, France, and supported the hypothesis that typhus was imported into Europe by Spanish soldiers returning from America. R. prowazekii was also detected in the remains of soldiers of Napoleon's Grand Army in Vilnius, Lithuania, which indicates that Napoleon's soldiers had epidemic typhus. The purpose of this article is to underscore the modern comprehension of clinical epidemic typhus, focus on the historical relationships of the disease, and examine the use of paleomicrobiology in the detection of past epidemic typhus outbreaks.
Assuntos
Surtos de Doenças , Fósseis/microbiologia , Paleopatologia/métodos , Rickettsia prowazekii/isolamento & purificação , Tifo Epidêmico Transmitido por Piolhos/epidemiologia , Tifo Epidêmico Transmitido por Piolhos/história , Animais , Técnicas Bacteriológicas/métodos , Saúde Global , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Pediculus/crescimento & desenvolvimento , Pediculus/microbiologia , Reação em Cadeia da Polimerase/métodos , Rickettsia prowazekii/genéticaRESUMO
The human head louse, Pediculus humanus capitis, is subdivided into several significantly divergent mitochondrial haplogroups, each with particular geographical distributions. Historically, they are among the oldest human parasites, representing an excellent marker for tracking older events in human evolutionary history. In this study, ancient DNA analysis using real-time polymerase chain reaction (qPCR), combined with conventional PCR, was applied to the remains of twenty-four ancient head lice and their eggs from the Roman period which were recovered from Israel. The lice and eggs were found in three combs, one of which was recovered from archaeological excavations in the Hatzeva area of the Judean desert, and two of which found in Moa, in the Arava region, close to the Dead Sea. Results show that the head lice remains dating approximately to 2,000 years old have a cytb haplogroup A, which is worldwide in distribution, and haplogroup B, which has thus far only been found in contemporary lice from America, Europe, Australia and, most recently, Africa. More specifically, this haplogroup B has a B36 haplotype, the most common among B haplogroups, and has been present in America for at least 4,000 years. The present findings confirm that clade B lice existed, at least in the Middle East, prior to contacts between Native Americans and Europeans. These results support a Middle Eastern origin for clade B followed by its introduction into the New World with the early peoples. Lastly, the presence of Acinetobacter baumannii DNA was demonstrated by qPCR and sequencing in four head lice remains belonging to clade A.