Background Head lice infestation (Pediculosis) is one of the most important health challenges particularly in primary school-aged children. It is often present among 6–11-year-old students in various tropical and temperate regions of the world. The aim of this study was to examine epidemiologic indices and comparative analysis of two pyrethroid-based and one non-chemical pediculicide products on head lice treatment of primary school girls in a rural setting of Fars province, south Iran, as part of a randomized controlled assessor blind trial. Methods Before treatment, infested students were screened using plastic detection combs to find live head lice. Three independent parallel groups, each with about 25 participants (#77) were eventually twice with a week apart treated with either 1% permethrin, 0.2% parasidose (d-phenothrin) or 4% dimeticone lotion preparations. In each case, a questionnaire form was completed on epidemiologic factors. Data were registered after a fortnight from primary scalp treatment and re-inspection on days 2, 6, 9 and 14. Data analyses were performed using Chi-square test with a P-value < 0.05 being taken as statistically significant. Results From 3728 inspected students, 87 (2.33%) girls were infested with head lice, Pediculus humanus capitis De Geer, 1778. Ten students dropped out pertaining to exclusion criteria. No significant correlation was found between head lice infestation level and hair length, hair style, itching, nationality, age, settlement site and baths; but there was a significant relationship between age and hair style (P = 0.027). The efficacy values on each of the above re-inspection days from each of the three treatments were 81, 74, 70 and 63% for permethrin; 83, 92, 100 and 100% for dimeticone; and 96, 88, 96 and 92% for d-phenothrin; respectively. A quartile difference in efficacy of permethrin relative to dimeticone on day 14 represented the scale of head lice resistance to permethrin treatment. There were significant statistical differences in case re-inspection days 9 (P = 0.008) and 14 (P = 0.003) post treatment. Only two dropout cases, one non-compliant and the other lost before the second-week treatment, from permethrin trial were observed following two applications a week apart. Conclusions Dimeticone lotion had the fullest efficacy (100%) among all treatments. This high cure rate was attributed to the low level of infestation and the extent of patients’ involvement. Parasidose swiftly ameliorated the infested cases by the second day since initial treatment. Female third grade students were the most infested cohort. Trial registration Current Controlled Trials- IRCT2016041627408N1, Dated: 21-08-2017.
Head lice (Pediculus humanus capitis) are one of the most common insects causing infestations in humans worldwide, and infestation is associated with adverse socio-economic and public health effects. The development of genetic insensitivity (e.g., target site insensitivity = knockdown resistance or kdr) to topical insecticides has impaired effective treatment. Therefore, this study was undertaken to review and meta-analyze the frequency of pyrethroid resistance in treated head louse populations from the beginning of 2000 to the end of June 2021 worldwide. In order to accomplish this, all English language articles published over this period were extracted and reviewed. Statistical analyses of data were performed using fixed and random effect model tests in meta-analysis, Cochrane, meta-regression and I2 index. A total of 24 articles from an initial sample size of 5033 were accepted into this systematic review. The mean frequency of pyrethroid resistance was estimated to be 76.9%. In collected resistant lice, 64.4% were homozygote and 30.3% were heterozygote resistant. Globally, four countries (Australia, England, Israel, and Turkey) have 100% kdr gene frequencies, likely resulting in the ineffectiveness of pyrethrin- and pyrethroid-based pediculicides. The highest resistance recorded in these studies was against permethrin. This study shows that pyrethroid resistance is found at relatively high frequencies in many countries. As a result, treatment with current insecticides may not be effective and is likely the cause of increased levels of infestations. It is recommended that resistance status be evaluated prior to insecticide treatment, to increase efficacy.
Ghir-Karzin district is one of the most important endemic foci of visceral leishmaniaisis (VL) in Fars province of southern Iran. To identify the vector(s) of Leishmania in this focus, a total of 2,539 sand flies were collected during June to September 2005. Eleven species (six Phlebotomus and five Sergentomyia) were identified, of which Phlebotomus papatasi Scopoli and Phlebotomus major Annandale were the first (37.4%) and third (11.2%) most common species, respectively. Natural leptomonad infections were observed in two P. papatasi (4.25%) and three P. major (6.65%) specimens on dissection and microscopic examination. Using a Leishmania genus-specific standard polymerase chain reaction (PCR; primers RV1-RV2) and a species-specific nested-PCR (primers LINR4, LIN17, and LIN 19), Leishmania infantum and Leishmania major kinetoplast minicircle DNA was detected in 6 of 72 P. major (8.3%) and 4 of 65 P. papatasi (6.1%), respectively. This is the first detection of L. infantum in P. major, implicating this sand fly as a probable vector of VL in Iran.
The genus Pratylenchoides has recently been transferred from the family Pratylenchidae to Merliniidae. To investigate further the relationship between these ‘Pratylenchus-like’ species (residing in the subfamily Pratylenchoidinae) and the subfamily Merliniinae, more than 500 soil samples were collected from various natural and agronomic habitats in the northern and north-western provinces of Iran. In this study, paratypes or populations of 22 species of Pratylenchoides, including the Iranian populations of P. alkani, P. crenicauda, P. erzurumensis, P. laticauda, P. nevadensis, P. ritteri and an undescribed species, were studied. Intra- and interspecies variation of the following characters were investigated: position of the pharyngeal gland nuclei, shape of female and male head, striation of female tail terminus, number of lateral lines at mid-body and in phasmid region for females, presence of intestinal fasciculi, and shape of sperm. Combining morphological and molecular data prompted us to propose two clusters of related Pratylenchoides species. One cluster includes P. crenicauda, P. variabilis and P. erzurumensis, whereas the second cluster consists of P. alkani, P. nevadensis and P. ritteri. Our data point to a sister positioning of P. magnicauda vis-à-vis all Pratylenchoides species included in this research. Analyses of SSU rDNA (for family and subfamily relationships) and partial LSU rDNA sequences (for intrageneric relationships) data revealed: i) the distal and nested positioning of all Pratylenchoidinae within the Merliniidae; ii) the single transition from ectoparasitism to migratory endoparasitism within the family Merliniidae corresponds with the current subfamily partitioning; and iii) support for the monophyletic nature of the genus Pratylenchoides.
Background Scorpions as a venomous arthropod can defend and capture the prey by secretion of venom into their venomic sacs. The venom is a mixture of a variety of compounds with specific biological activities, such as phospholipase A2 (PLA2) enzyme to be present in scorpion venom. This study is the first investigation of structural and molecular characterization of PLA2 from Iranian scorpion, S. maurus that can be added to the literature when targeting molecular characterization of PLA2 coding gene from venom glands of Iranian S. maurus. Results S. maurus PLA2 with 432 base pair (bp) nucleotide length encoded a protein of 144 amino acid residues and 16.34 kilodaltons (kDa). According to DiANNA 1.1 web server prediction, this protein had 5 disulfide bridges. The deposited PLA2 in GenBank (MW241004) was very similar to S. maurus (MF347455.1) with 95.14% identity. The phylogenetic analysis indicated that our PLA2 had a close relationship with insect PLA2. Our PLA2 had 38.83% identity with bee venom PLA2 according to SWISS-MODEL prediction and 100% confidence and 39% identity with insect phospholipase A2 family, which was predicted by Phyre2. Our PLA2 was similar to chain A of bee venom PLA2. Conserved domains on target PLA2 contained 17–118 amino acid in length and 45–52 amino acids in the active site. There was no signal peptide. Conclusions In the light of our results, the coding sequence of characterized PLA2 was a member of the PLA2 superfamily. According to the three-dimensional structure prediction, the target PLA2 with five disulfide bonds has a very high similarity to the structure of phospholipase A2 belonged to the group III subfamily. Interestingly, the active site residue of target PLA2 also has the His-Asp acid pair and the effective amino acid in catalytic domain of it was\({\text{H}\text{i}\text{s}}^{49}\).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.