Frequency of pyrethroid resistance in human head louse treatment: systematic review and meta-analysis.

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.

TITLE: Fréquence de la résistance aux pyréthroïdes dans le traitement du pou de tête chez l'homme : revue systématique et méta-analyse. ABSTRACT: Les poux de tête (Pediculus humanus capitis) sont l'un des insectes les plus courants à l'origine d'infestations chez l'homme dans le monde, et l'infestation est associée à des effets socio-économiques et de santé publique néfastes. Le développement d'une insensibilité génétique (par exemple, l'insensibilité au site cible = résistance knockdown ou kdr) aux insecticides topiques a altéré l'efficacité de leur traitement. Par conséquent, cette étude a été entreprise pour examiner et méta-analyser la fréquence de la résistance aux pyréthroïdes dans les populations de poux de tête étudiées du début 2000 à la fin juin 2021 dans le monde. Pour ce faire, tous les articles en anglais publiés au cours de cette période ont été extraits et examinés. Les analyses statistiques des données ont été effectuées à l'aide de tests de modèles à effets fixes et aléatoires dans la méta-analyse, Cochrane, méta-régression et indice I2. Un total de 24 articles provenant d'un échantillon initial de 5033 ont été acceptés dans cette revue systématique. La fréquence moyenne de la résistance aux pyréthroïdes a été estimée à 76,9 %. Chez les poux résistants collectés, 64,4 % étaient homozygotes résistants et 30,3 % étaient hétérozygotes résistants. À l'échelle mondiale, quatre pays (Australie, Angleterre, Israël et Turquie) ont des fréquences de gène kdr de 100 %, ce qui entraîne probablement une inefficacité des pédiculicides à base de pyréthrine et de pyréthrinoïde. La résistance la plus élevée enregistrée dans ces études était celle contre la perméthrine. Cette étude montre que la résistance aux pyréthroïdes est trouvée à des fréquences relativement élevées dans de nombreux pays. En conséquence, le traitement avec les insecticides actuels peut ne pas être efficace et est probablement la cause d'une augmentation des niveaux d'infestation. Il est recommandé d'évaluer le statut de résistance avant le traitement insecticide, pour augmenter son efficacité.

Wound healing potential: evaluation of molecular profiling and amplification of Lucilia sericata angiopoietin-1 mRNA mid-part.

OBJECTIVE: High prevalence of chronic ulcers and the burden of disease necessitate the increasingly significant production of new recombinant proteins in the world. The angiopoietin-1 enzyme is a part of the growth factors group which is secreted by Lucilia sericata (Diptera: Calliphoridae) larvae when they meet lesions to ensure maggot therapy. It is one of the most potent proteins in wound healing. Given its essential role, the angiopoietin-1 gene of L. sericata was characterized, which provided some necessary information on its identity. RESULTS: The mid-part of the angiopoietin-1 mRNA sequence was thus characterized based on the design of different primers such as exon-exon junction, conserved regions, and specific region primers via conventional polymerase chain reaction (PCR). Its structural features were configured by in silico method. The sequence of mid-part (390 bp) of angiopoietin-1 was determined empirically, and BLAST analysis unraveled its high identity (85%) with the sequence of angiopoietin-1 mRNA of the larval housefly, Musca domestica. The homology of this enzyme also exhibited that its nucleic acid sequence was very similar to the domains of angiopoietin-1 in Lucilia cuprina. The current data are instructive and critical to evaluate the action of this enzyme in recombinant protein production in future molecular studies on wound healing.

Molecular characterization of the netrin-1 UNC-5 receptor in Lucilia sericata larvae.

Larval therapy with Lucilia sericata is a promising strategy in wound healing. Axon guidance molecules play vital roles during the development of the nervous system and also regulate the capacity of neuronal restoration in wound healing. Netrin-1, one of the proteins that larvae secrete, plays a useful role in cell migration and nerve tissue regeneration. The UNC-5 receptor combines with a netrin-1 signal and transmits the signal from one side of the membrane to the other side, initiating a change in cell activity. In the current study, we identified the full length of the UNC-5 receptor mRNA in L. sericata using different sets of primers, including exon junction and specific region primers. The coding sequence (CDS) of the UNC-5 receptor was sequenced and identified to include 633 base-pair nucleic acids, and BLAST analysis on its nucleotide sequence revealed 96% identity with the Lucilia cuprina netrin-1 UNC-5 receptor. The protein residue included 210 amino acids (aa) and coded for a protein with 24 kD weight. This gene lacked the signal peptide. Furthermore, the UPA domain is conserved in UNC-5. It lied at the interval of 26-131 aa. We identified the CDS of netrin-1 UNC-5 receptor in L. sericata. It could be applied to research activities implementing a new essential component design in wound healing.

First survey of forensically important insects from human corpses in Shiraz, Iran.

The presence of insects on human cadavers has potential judicial value in medicolegal cases. This research emphasized the important role of insects in postmortem decomposition. It was conducted to investigate the composition and abundance of insects from human corpses during autopsies in legal medicine. It was implemented in the city of Shiraz, south Iran. Insects associated with human corpses were carefully collected and put into labelled vials. They were then identified using valid taxonomic keys. Fifteen outdoor (67%) and indoor discovered cadavers were examined. All but one was covered at the time of discovery. From these several species of entomofauna played important roles in the minimum postmortem interval (minPMI) estimate. Insects included the orders of Diptera and Coleoptera. Overall, 14 different species of arthropods were identified. Within Diptera, 2 families of Sarcophagidae and Calliphoridae were present in 73% of the cases with Calliphora vicina Robineau-Desvoidy and Chrysomya albiceps Wiedemann accounting for about half of the cases. The latter family members, Calliphoridae, were more frequently (52%) collected in autumn and winter. Only 4/15 outdoor cadavers had beetles. Four species of Coleopterans; namely Dermestes frischii Kugelann, Nitidula flavomaculata Rossi, Creophilus maxillosus Linnaeus and Saprinus chalcites Illiger; were recorded for the first time from 3 corpses in Iran. The presence and diversity of different insects on human corpses could contribute to the advancement of forensic entomology knowledge and the refined estimates of minPMI in medicolegal cases.

Identification and frequency distribution of Leishmania (L.) major infections in sand flies from a new endemic ZCL focus in southeast Iran.

Zoonotic cutaneous leishmaniasis (ZCL) is an important public health challenge in Iran. It is often caused by the protozoan parasite, Leishmania major. This pathogen is principally transmitted by the infectious bites of adult female phlebotomine sand flies which belong to the subgenus Phlebotomus (Phlebotomus) Rondani and Berte (Diptera: Psychodidae). A recent outbreak of clinical ZCL cases in the rural district of Jask, Hormozgan province, southern Iran prompted the identification of sand flies naturally infected with L. major using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). A total of 8,123 wild sand flies were caught using sticky paper traps indoors and outdoors in seven villages of Jask from March 2007 to February 2008. About 120 trap-nights per month were carried out during peak seasonal density. Eight sand fly species of two distinct genera were morphologically identified. The most abundant species, Phlebotomus papatasi (≈60%) and Phlebotomus salehi (17%), had simultaneous population peaks in May and October. The anthropophilic index of P. papatasi was approximately twice that of P. salehi. PCR reactivity of L. major infections in P. salehi was weaker than those in P. papatasi. This is discussed with regard to their role in the natural transmission cycle of ZCL. This study provided the first PCR and ELISA evidence on P. salehi as a vector of L. major parasites in a new endemic region of ZCL in southeast Iran.