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Parasitology Research May 2021Head lice (Pediculus humanus capitis) are worldwide obligate human ectoparasites, with high implications in pediatrics. In Europe, first-line topical neurotoxic...
Head lice (Pediculus humanus capitis) are worldwide obligate human ectoparasites, with high implications in pediatrics. In Europe, first-line topical neurotoxic insecticidal therapeutic strategies are being replaced by topical physically acting agents as the first-choice treatment. Safety of the active ingredients and high efficacy in a one-time single-dose treatment with a brief treatment application time are key issues for consumer use and effective compliance. The aim of this study was to assess the in vitro efficacy of a newly developed squalane and dimethicone-based pediculicidal formula, against motile head lice and eggs after 2 and 5 min immersion in the product, as well as its skin tolerance and acceptability under dermatological and pediatric expert control in children with atopic skin. The results indicate that at both time points, 100% mortality rate of head lice crawling stages and late-stage eggs was achieved. The formula was well tolerated and suitable for children with atopic skin from 12 months of age. Showing high in vitro efficacy and good skin acceptability, this solution is presented as a new safe alternative therapy for treatment of head lice infestations.
Topics: Animals; Child, Preschool; Dimethylpolysiloxanes; Europe; Female; Humans; Infant; Insecticides; Lice Infestations; Male; Pediculus; Skin; Squalene
PubMed: 33797611
DOI: 10.1007/s00436-021-07113-y -
IDCases 2020Body lice and bed bugs are hematophagous insects that parasitize humans. Body lice are established vectors of several bacterial pathogens (e.g. ). Bed bugs are...
Body lice and bed bugs are hematophagous insects that parasitize humans. Body lice are established vectors of several bacterial pathogens (e.g. ). Bed bugs are biologically competent vectors of some of the same agents, but their vectorial capacity for these in nature is unclear. In particular, a lack of exposure to louse-borne pathogens in bed bugs in the field could be a factor that limits their contribution to transmission. Here, we describe a case of a patient seen in an urban emergency department who was suffering from infestation with both body lice and bed bugs. Insects were collected from the patient and tested for the presence of louse-borne bacterial pathogens using 16S rRNA gene amplicon sequencing. Although no or were detected, this case provides evidence of ecological overlap between body lice and bed bugs and highlights several potential risk factors for co-infestation. The ecological relationships between bed bugs, body lice, and louse-borne bacteria should be further investigated in the field to determine the frequency of co-infestations and identify possible instances of pathogen infection in bed bugs.
PubMed: 31988849
DOI: 10.1016/j.idcr.2020.e00696 -
Trends in Parasitology Sep 2016Several arthropod taxa live exclusively on vertebrate blood. This food source lacks essential metabolites required for the maintenance of metabolic homeostasis, and as... (Review)
Review
Several arthropod taxa live exclusively on vertebrate blood. This food source lacks essential metabolites required for the maintenance of metabolic homeostasis, and as such, these arthropods have formed symbioses with nutrient-supplementing microbes that facilitate their host's 'hematophagous' feeding ecology. Herein we highlight metabolic contributions of bacterial symbionts that reside within tsetse flies, bed bugs, lice, reduviid bugs, and ticks, with specific emphasis on B vitamin and cofactor biosynthesis. Importantly, these arthropods can transmit pathogens of medical and veterinary relevance and/or cause infestations that induce psychological and dermatological distress. Microbial metabolites, and the biochemical pathways that generate them, can serve as specific targets of novel control mechanisms aimed at disrupting the metabolism of hematophagous arthropods, thus combatting pest invasion and vector-borne pathogen transmission.
Topics: Animals; Arthropod Vectors; Drug Delivery Systems; Homeostasis; Host-Parasite Interactions; Parasitic Diseases; Symbiosis
PubMed: 27236581
DOI: 10.1016/j.pt.2016.05.002 -
Frontiers in Cellular and Infection... 2019is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have... (Review)
Review
is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have distinct ecologies. Phylogenetically, they are classified on six mitochondrial clades (A, B, C, D, E, and F), head louse encompasses the full genetic diversity of clades, while body louse belongs to clades A and D. Recent studies suggested that not only body louse, but also head louse can transmit disease, which warrants greater attention as a serious public health problem. The recent sequencing of body louse genome confirmed that has the smallest genome of any hemimetabolous insect reported to date, and also revealed numerous interesting characteristics in the nuclear and mitochondrial genomes. The transcriptome analyses showed that body and head lice were almost genetically identical. Indeed, the phenotypic flexibility associated with the emergence of body lice, is probably a result of regulatory changes, perhaps epigenetic in origin, triggered by environmental signals. Current lice control strategies have proven unsuccessful. For instance, ivermectin represents a relatively new and very promising pediculicide. However, ivermectin resistance in the field has begun to be reported. Therefore, novel opportunities for pest control strategies are needed. Our objective here is to review the current state of knowledge on the biology, epidemiology, phylogeny, disease-vector and control of this fascinating and very intimate human parasite.
Topics: Animals; Bacteria; Communicable Disease Control; Evolution, Molecular; Genome; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Lice Infestations; Mitochondria; Pediculus; Phylogeny; Phylogeography
PubMed: 32039050
DOI: 10.3389/fcimb.2019.00474 -
Health Science Reports Nov 2023Head lice is a public health problem of worldwide distribution, particularly among school children and girls. Head lice infestation (HLI) can lead to negative social and...
BACKGROUND AND AIMS
Head lice is a public health problem of worldwide distribution, particularly among school children and girls. Head lice infestation (HLI) can lead to negative social and psychological outcomes such as distress and anxiety in children and their families. Hence, the present study aimed to investigate the role of cognitive-behavioral factors in its spread and prevention among adolescent girls.
METHODS
The cross-sectional study was conducted among 276 school-aged adolescent girls from September 2022 to January 2023 in Herris, a city located in Northwest Iran. A multistage cluster random sample was used to recruit adolescent girls in secondary schools. Two schools were randomly selected from five secondary schools. Then, students in each school were randomly selected from a school list. Data were collected using a valid and reliable questionnaire.
RESULTS
The high protective behaviors were significantly associated with the number of family members ( = 0.158; value = 0.012). An additional 21.8% of the variation in preventive behaviors was explained by cognitive factors as predictor variables ( value > 0.05). Perceived collective family efficacy, perceived barriers, perceived self-efficacy, and response efficacy were predictors of head lice preventive behaviors, respectively. Among all variables, perceived collective family efficacy was the strongest predictor.
CONCLUSIONS
The findings of current research support the determinants of the cognitive-behavioral factors in the spread and prevention of HLI. It is better to involve these factors in school-based educational programs by policymakers and healthcare providers.
PubMed: 37927538
DOI: 10.1002/hsr2.1679 -
The American Journal of Tropical... Oct 2021Tungiasis (sand flea disease) is a neglected tropical disease caused by penetration of female sand fleas, Tunga penetrans, into a person's skin usually in their feet.... (Review)
Review
Tungiasis (sand flea disease) is a neglected tropical disease caused by penetration of female sand fleas, Tunga penetrans, into a person's skin usually in their feet. The disease inflicts immense pain and suffering on millions of people, particularly children. The condition is most prevalent in Latin America, the Caribbean, and sub-Saharan Africa. Currently, there is no standard drug treatment for tungiasis. The available treatment options are fairly limited and unrealistic to use in endemic areas; as a result, in desperation, the affected people do more harm to themselves by extracting the fleas with non-sterile instruments, further exposing themselves to secondary bacterial infections and/or transmission of diseases such as hepatitis B virus, hepatitis C virus, or HIV. This highlights the urgent need for simpler, safer, and effective treatment options for tungiasis. Tea tree oil (TTO) has long been used as an antiseptic with extensive safety and efficacy data. The evidence on parasiticidal properties of TTO against ectoparasites such as head lice, mites, and fleas is also compelling. The purpose of this review is to discuss the current tungiasis treatment challenges in endemic settings and highlight the potential role of TTO in the treatment of tungiasis.
Topics: Africa South of the Sahara; Animals; Caribbean Region; Child; Female; Flea Infestations; Humans; Skin; Tea Tree Oil; Treatment Outcome; Tunga; Tungiasis
PubMed: 34731831
DOI: 10.4269/ajtmh.21-0427 -
Medicina (Kaunas, Lithuania) Nov 2022Background and Objectives: Pediculosis, or head lice infestation, is a widespread health problem that can affect anyone, regardless of gender, age, or social background....
Background and Objectives: Pediculosis, or head lice infestation, is a widespread health problem that can affect anyone, regardless of gender, age, or social background. The purpose of this study was to clarify the occurrence of pediculosis among Estonian preschool- and primary school-aged children according to their parents and the parent’s awareness of pediculosis and related behaviors. Materials and Methods: An online questionnaire was completed by the parents of the preschool children (n = 1141) in 2019 and the parents of the elementary school children (n = 362) in 2021. For the descriptive data, t-test, Mann−Whitney or χ2 test, linear regression, and logistic regression analyses were applied. Results: According to the parents, pediculosis had occurred in 34.7% of the children, and more than one-third of pediculosis patients had experienced it more than twice. Lice were mainly acquired from elementary school or preschool and less often from friends, relatives, or training environments. Parents’ knowledge of head lice was rather good; the average score of the correct answers was 14.0 ± 3.4 (max. 20). In the multivariate analysis, higher age (coefficient 0.07, p < 0.001), healthcare education (coefficient 1.19, p < 0.001), and a previous occurrence of pediculosis in a family (coefficient 1.95; p < 0.001) were factors influencing better knowledge. In order to treat the infestation, antilice shampoo and combing were the most often used methods. Conclusion: Despite parents’ awareness, pediculosis infestations continue to be common among our children.
Topics: Animals; Humans; Child, Preschool; Child; Lice Infestations; Estonia; Pediculus; Parents; Surveys and Questionnaires; Prevalence
PubMed: 36556975
DOI: 10.3390/medicina58121773 -
Health Equity 2021The prevalence of head lice in poor rural communities and urban slums is estimated to be between 28% and 43% in Brazil, respectively. Children are among the most...
The prevalence of head lice in poor rural communities and urban slums is estimated to be between 28% and 43% in Brazil, respectively. Children are among the most affected, often in clusters within schools. We launched a program intending to tackle the social stigma associated with head lice using scientific information and a local traditional remedy as a way to lower the prevalence of head lice in a low-resource community. A program involving the entire school community and the teachers addressed how to treat head lice and avoid new infestations. An affordable solution widely used in traditional Brazilian medicine was provided for the ones infested. Evaluation of the outcome was based on direct observation and was designed as a satisfaction survey. The study complied with the criteria for Standards for Reporting Qualitative Research (SRQR). Two hundred and eighty participants, including parents and siblings of the school children, took part in the program. Among them, 24% (=67) had head lice, with girls representing 85% of cases; 74.7% of participants infested with head lice were between 4 and 10 years old; 55.2% (=37) of participants infested showed no signs of nits or adult lice after the program. This experience suggests that the use of playful activities associated with a well-known and accessible local product to treat head lice in low-income families gathered a high degree of community adherence and may be an important tool in overcoming health inequalities.
PubMed: 34036214
DOI: 10.1089/heq.2020.0065 -
Pesticide Biochemistry and Physiology Feb 2022Pediculus 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... (Review)
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.
Topics: Animals; Humans; Insecticides; Lice Infestations; Pediculus
PubMed: 35082036
DOI: 10.1016/j.pestbp.2021.105013 -
World Journal of Clinical Cases Nov 2021Crab lice () infestation can occur at any age, to either males or females, and across all regions of the world. However, cases involving the eyelashes and adjacent...
BACKGROUND
Crab lice () infestation can occur at any age, to either males or females, and across all regions of the world. However, cases involving the eyelashes and adjacent eyelids (phthiriasis palpebrarum) are rare. Usually occurring as a sexually transmitted disease, crab lice can be spread by poor hygiene or in a dirty environment through direct contact with contaminated skin (hands) or textiles (towels and clothing).
CASE SUMMARY
A 50-year-old woman presented to our hospital with a 2-wk history of chronic eyelid pain and itching in the right eye, which exacerbated in the evening hours and which had not resolved following a 1-wk course of antibiotics and corticosteroid ointments (for blepharitis diagnosis from another hospital). A careful ophthalmic slit-lamp and light microscope examination revealed multiple crab lice and nits on the right upper eyelashes; the right and left lower eyelashes were normal. Following the new diagnosis of phthiriasis palpebrarum, the patient was treated by removing the affected eyelashes, the crab lice, and their nits completely. Additionally, the eyelids were washed once with povidone-iodine. A follow-up examination at 2 wk later showed complete resolution of symptoms and no evidence of re-infection.
CONCLUSION
This case emphasizes the importance of correct diagnosis and complete removal of eyelashes, crab lice and nits to cure phthiriasis palpebrarum.
PubMed: 34904106
DOI: 10.12998/wjcc.v9.i33.10323