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.

Indirect costs associated with skin infectious disease in children: a systematic review

Background There are limited data in the literature on the indirect costs associated with skin and soft tissue infections (SSTIs) in the pediatric population. This study aimed to conduct a systematic review of the indirect costs associated with SSTIs in children. Methods The search was conducted in PubMed, SCOPUS, and Web of Science up to January 2020. Thirteen search strategies were designed combining MeSH terms and free terms. SSTIs were defined as bacterial or viral infections, dermatomycoses, and parasitic infestations. Only primary studies were included. All analyzed costs were converted to 2020 Euros. Results Thirteen of the identified publications presented indirect costs of SSTIs in children and were conducted in Argentina, Australia, Brazil, Hungary, New Zealand, Poland, Spain, Taiwan, and the USA. Nine studies described indirect costs associated with infection of Varicella-zoster virus: lost workdays by outpatient caregivers ranged from 0.27 to 7.8, and up to 6.14 if caring for inpatients; total productivity losses ranged from €1.16 to €257.46 per patient. Three studies reported indirect costs associated with acute bacterial SSTIs (community-associated methicillin-resistant Staphylococcus aureus) in children: total productivity losses ranged from €1,814.39 to €8,224.06 per patient, based on impetigo, cellulitis, and folliculitis. One study of parasitic infestations (Pediculus humanus capitis) reported total indirect costs per patient of €68.57 (formal care) plus €21.41 due to time lost by parents in purchasing treatment. Conclusions The economic burden of SSTIs is highly relevant but underestimated due to the lack of studies reporting indirect costs. Further cost studies will allow a better understanding of the magnitude of the financial burden of the disease.

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

Borreliae Part 2: Borrelia Relapsing Fever Group and Unclassified Borrelia

Borreliae of the relapsing fever group (RFG) are heterogenous and can be divided mainly into three groups according to vectors, namely the soft-tick-borne relapsing fever (STBRF) Borreliae, the hard-tick-borne relapsing fever (HTBRF) Borreliae, the louse-borne relapsing fever (LBRF) Borreliae, and the avian relapsing fever ones. With respect to the geographical distribution, the STBRF Borreliae are further subdivided into Old World and New World strains. Except for the Avian relapsing fever group Borreliae, which cause avian spirochetosis, all the others share infectivity in humans. They are indeed the etiological agent of both endemic and epidemic forms of relapsing fever, causing high spirochaetemia and fever. Vectors are primarily soft ticks of Ornithodoros spp. in the STBRF group; hard ticks, notably Ixodes sp., Amblyomma sp., Dermacentor sp., and Rhipicephalus sp., in the HTBRF group; and the louse pediculus humanus humanus in the TBRF one. A recent hypothesis was supported for a common ancestor of RFG Borreliae, transmitted at the beginning by hard-body ticks. Accordingly, STBRF Borreliae switched to use soft-bodied ticks as a vector, which was followed by the use of lice by Borrelia recurrentis. There are also new candidate species of Borreliae, at present unclassified, which are also described in this review.