Investigation on prevalence, risk factors, and genetic diversity of Pediculus humanus capitis among primary school children

Pediculosis is an integumentary disease caused by the ecto-parasite Pediculus humanus capitis, which infests human hair. It is a common public health problem that is most prominent worldwide in elementary school children. The current study aimed to investigate the prevalence, risk factors, and genetic diversity of P. humanus capitis among primary school children in the Erbil province. For this purpose, this study was conducted from October 2019 to December 2019 among 1100 randomly selected elementary school children aged 6-12. Data collection was performed via a regular questionnaire and physical hair examination. For the genetic diversity part, after collecting one louse randomly from each individual, DNA was extracted. The mitochondrial Cox1 gene was then amplified by universal primer and PCR. Gene sequencing was performed by ABI (BioNEER, South Korea). Data analysis was done by Chi-Square and T-test using the SPSS ver. 23. The overall infestation rate was 21.27%, and the rate was significantly higher among females (34.93%) compared to males (7.91%). Some variables had found the prevalence rate to be strongly affected. This included age; the rate was not significant (26.87%) in the age group 8-9 years compared to other age groups. According to hair length, the rate was significantly increased (36.52%) among children with tall hair. In terms of hair type, the incidence of curly-haired children was significantly higher (31.54%); in terms of hair color, there were not significant differences among blonde children (25.90%) and others. According to the results of Cox1 gene sequencing, of 234 infested children to lice, 86 (36.75%) of them were exposed to clade A, 38 (16.24%) were exposed to clade B, clade C has not been seen among any children (0%), 105 students (44.87%) were exposed to clade D, and 5 of them exposed to clade E (2.14%). Eventually, a significantly higher incidence (33.78%) was reported in rural primary school children. The infection rate of human head lice in Erbil province is still high, which is one of the health problems of children in public schools.

INFEKSI OPORTUNISTIK TINEA CAPITIS PADA PENDERITA PEDICULOSIS CAPITIS

Pediculosis capitis merupakan penyakit infeksi pada kulit kepala manusia yang disebabkan oleh infestasi ektoparasit Pediculus humanus capitis yang dapat menular di kepala tanpa disadari karena kontak erat di lingkungan yang sama seperti asrama pesantren. Di kepala penderita pediculosis ditemukan banyak lesi pada kulit, rambut saling melekat, bintik-bintik hitam atau coklat pada pangkal rambut, radang pada kulit kepala serta eksudat nanah yang berasal dari luka gigitan Pediculus humanus capitis yang meradang. Infeksi sekunder berupa tinea capitis dapat menyerang penderita pediculosis. Infeksi ini disebabkan dermatofita genus Microsforum sp dan Trichophyton sp. Penelitian ini bertujuan untuk mengetahui jenis jamur penyebab tinea capitis pada kulit kepala santriwati pesantren di Makassar. Jenis penelitian yang digunakan adalah penelitian deskriptif dengan mengkultur spesimen pada media Sabouraud Dextrose Agar (SDA) dan dilanjutkan dengan identifikasi jamur. Hasil penelitian dari 10 sampel menunjukkan bahwa 1 sampel terinfeksi Microsporum audouinii.

In vitro experiments of Pediculus humanus capitis (Phthiraptera: Pediculidae) resistance to permethrin and 6-paradol in East Jakarta: Detoxification enzyme activity and electron microscopic changes in lice

Background and Aim: Pediculus humanus capitis, the human head louse, remains a global health problem. This study evaluated the resistance of head lice to permethrin and 6-paradol mediated by in vitro detoxification enzyme activity experiments and to describe physical changes in the lice using scanning electron microscopy (SEM). Materials and Methods: The adult stages of P. h. capitis were collected from patients exposed to 1% permethrin and three different concentrations of 6-paradol (0.00005%, 0.0001%, and 0.00015%) using a filter paper diffusion bioassay. Healthy P. h. capitis adults served as the control. The in vitro bioassays were conducted after 10, 20, 30, and 60 min of exposure. The activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), and oxidase were analyzed. Physical changes in the lice were analyzed using SEM. Results: Permethrin and 6-paradol exhibited low toxicity against the lice. At 60 min, 1% permethrin had killed 36.7% of the lice present, while 6-paradol had killed 66.7-86.7%. Permethrin induced significantly elevated AChE, GST, and oxidase activity; 6-paradol also caused significantly elevated AChE, GST, and oxidase activity. Permethrin did not cause any ultrastructural morphological changes on the lice, while 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice. Conclusion: This in vitro experimental of P. h. capitis is the first study to report P. h. capitis in East Jakarta shows complete resistance to permethrin and 6-paradol, and to describe the associated increase in AChE, GST, and oxidase activity. It was observed that 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice.

Activity Test of Durian Peels Essential Oil (Durio zibethinus) as an Antipediculosis Against Pediculus humanus capitis Linn. (Anoplura: Pediculidae)

<p class="Judul1"><span lang="EN-US">Pediculosis is a disease caused by infestation of head lice (<em>Pediculus humanus capitis</em>) which is a blood-sucking obligate ectoparasite. The essential oil of durian fruit peel has active compounds that have the potential as vegetable pediculosides that can kill head lice. This study aimed to find the best concentration <span>of </span>essential oil from durian fruit peels that can kill head lice. The research design used with an essential oil concentration of 100%, 75%, 50%, 25%, distilled water as negative control and permethrin 1% as positive control, three repetitions and each concentration consisting of 10 flea tails. The parameters observed were the condition of lice morphologically based on the activity of limb movement, antenna movement and digestion, then the calculation of mortality was observed based on the time of the test. The results showed that the concentration of durian peel essential oil as an antipediculosis had a significant effect on the time of death of head lice, limb movement and digestion. The test result showed that the concentration is 100%, has a death time of 12 minutes <span>32 </span>seconds, 75% concentration was 16 minutes 28 seconds, 50% concentration was 21 minutes 11 seconds, 25% concentration was 32 minutes 23 seconds, negative control was 61 minutes 15 seconds. The fastest time of death in positive control for chemical pediculosides was 10 minutes 15 seconds. The conclusion in this study was that essential oils the dominan one is 1,5-naphthyridin-2-amine were proven to kill head lice and the best concentration was close to positive control, namely at a concentration of 100%.</span></p>

Pediculus humanus capitis: a study of the male genitalia using a combined stereoscopic, confocal laser scanning, and scanning electron microscopy approach

Background The male genital structures of arthropods are key features in the taxonomic and phylogenetic study of these organisms. The male genitalia of the head louse Pediculus humanus capitis are complex organs which are partly composed of structures that dynamically extrude during copulation. Methods Here, we describe the morphology of the genitalia of P. humanus capitis at the copulation stage, and at rest, by using stereoscopic microscopy, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). Results CLSM and SEM images revealed that the vesica is composed of two distinct anatomical parts, the proximal lobe and the distal lobe. Both lobes have short and narrow spines, as well as long and wide scales with either sharp or rounded tips. The rounded scales vary in size and have a wavy base and rounded tips, and thus resemble a tongue in appearance. We identified a gland-like area on the penis with 11 shallow circular depressions, and a flat area with 14–16 exit orifices. The apical end of the penis has a foliaceous trifurcation and serves to expel the contents of the ejaculatory duct. These characteristics were recorded for all the specimens analyzed, indicating that these structures are highly conserved; to our knowledge, they have not been previously reported for any suborder of lice. Conclusions To the best of our knowledge, our results reveal for the first time the morphological details, and complexity, of the male genitalia of the head louse P. humanus capitis at different stages of copulation. The new approach described here provided information that should be taken into consideration in future research on the genitalia of lice. Application of this approach will also impact the taxonomic and phylogenetic study of other insect taxa. Graphical Abstract

Molecular analysis of mitochrondrial cytb of Pediculus humanus capitis in Thailand revealed potential historical connection with South Asia

Background Pediculus humanus capitis or head louse is an obligate ectoparasite and its infestation remains a major public health issue worldwide. Molecular analysis divides head lice into six clades and intra-clade genetic differences have been identified. Several hypotheses have been formulated to elucidate the discrepancies of the variety of head lice among different regions of the world. It is currently concluded that head lice distribution might be associated with human migration history. This study aims to investigate genetic data of human head lice in Thailand. We believe that the analysis could help establish the correlation between local and global head lice populations. Method We investigated mitochondrial cytochrome b (cytb) gene of the collected 214 head lice to evaluate genetic diversity from 15 provinces among 6 regions of Thailand. The head lice genes were added to the global pool for the phylogenetic tree, Bayesian tree, Skyline plot, and median joining network construction. The biodiversity, neutrality tests, and population genetic differentiation among the 6 Thailand geographic regions were analyzed by DNAsp version 6. Results The phylogenetic tree analysis of 214 collected head lice are of clade A and clade C accounting for roughly 65% and 35% respectively. The Bayesian tree revealed a correlation of clade diversification and ancient human dispersal timeline. In Thailand, clade A is widespread in the country. Clade C is confined to only the Central, Southern, and Northeastern regions. We identified 50 novel haplotypes. Statistical analysis showed congruent results between genetic differentiation and population migration especially with South Asia. Conclusions Pediculosis remains problematic among children in the rural areas in Thailand. Cytb gene analysis of human head lice illustrated clade distribution and intra-clade diversity of different areas. Our study reported novel haplotypes of head lice in Thailand. Moreover, the statistic calculation provided a better understanding of their relationship with human, as an obligate human parasite and might help provide a better insight into the history of human population migration. Determination of the correlation between phylogenetic data and pediculicide resistance gene as well as residing bacteria are of interest for future studies.

Extensão acadêmica: utilizando à educação em saúde como instrumento de abordagem para a desmistificação da pediculose

Introdução: A pediculose é considerada um ectoparasito que é ocasionado pelo Pediculus humanus capitis que infesta somente o couro cabeludo do homem e que possui histórico de longa data, no qual facilita compreender todos os empirismos que surgem e são praticados, até os dias atuais, acerca dessa temática. Objetivo: Instigar a importância da pediculose para as crianças e toda a comunidade, assim como minimizar os fatores vinculados com os determinantes sociais da saúde relacionados com o piolho de cabeça. Metodologia: Estudo observacional e qualitativo, com a participação de crianças e adolescentes, com idade entre 6 e 18 anos, de escolas, centros e creches públicas do Rio de Janeiro. O desenvolvimento deste trabalho ocorreu por meio de exposições de materiais didáticos, bem como apresentação de ovos e ninfas do Pediculus humanus em microscópios, peças teatrais, rodas de conversa, quebra-cabeças, fantoches, animações em Power Point e panfletos, por meio de discentes de enfermagem que atuam no projeto de extensão de Parasitologia, para tornar mais palpável possível o conhecimento científico deste parasito. Resultados: O público-alvo a todo momento interagiu com os participantes do projeto, mostrando-se pró-ativos e interessados pela temática, além de ter sido notado as mudanças intelectuais sobre o piolho de cabeça e os comportamentos frente a este problema sociocultural. Conclusão: A importância da educação em saúde apresentada em atividades lúdicas e dinâmicas contribuiu em mudanças nos hábitos das atividades de vida diárias sobre essa doença parasitária e a relevância da participação de graduandos de Enfermagem para estimular a promoção à saúde.