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Travel Medicine and Infectious Disease 2023Human lice have always been a major public health concern due to their vector capacity for louse-borne infectious diseases, like trench fever, louse-borne relapsing... (Review)
Review
Human lice have always been a major public health concern due to their vector capacity for louse-borne infectious diseases, like trench fever, louse-borne relapsing fever, and epidemic fever, which are caused by Bartonella quintana, Borrelia recurrentis, and Rickettsia prowazekii, respectively. Those diseases are currently re-emerging in the regions of poor hygiene, social poverty, or wars with life-threatening consequences. These louse-borne diseases have also caused outbreaks among populations in jails and refugee camps. In addition, antibodies and DNAs to those pathogens have been steadily detected in homeless populations. Importantly, more bacterial pathogens have been detected in human lice, and some have been transmitted by human lice in laboratories. Here, we provide a comprehensive review and update on louse-borne infectious diseases/bacterial pathogens.
Topics: Animals; Humans; Typhus, Epidemic Louse-Borne; Relapsing Fever; Pediculus; Phthiraptera; Communicable Diseases
PubMed: 37567429
DOI: 10.1016/j.tmaid.2023.102630 -
The Pan African Medical Journal 2024
Topics: Animals; Humans; Pediculus; Eyelashes; Lice Infestations
PubMed: 38558554
DOI: 10.11604/pamj.2024.47.29.42559 -
Turkiye Parazitolojii Dergisi Mar 2024The purpose of this study was to investigate the prevalence of intestinal parasites and head lice in primary school-aged children and to determine a possible...
OBJECTIVE
The purpose of this study was to investigate the prevalence of intestinal parasites and head lice in primary school-aged children and to determine a possible relationship between the co-occurrence of ecto-endoparasites.
METHODS
The study were conducted in three schools in the center of Sivas: Sivas Karşıyaka Primary School, Kılavuz İMKB Primary School, and Karşıyaka 27 June Middle School. The presence of head lice and intestinal parasites was investigated in a total of 563 children aged 6 to 17, with 294 girls and 269 boys. Classroom teachers and students were provided with information about intestinal parasites, head lice, and methods of transmission and prevention, and a questionnaire was administered. During the head lice examination, students were inspected with a comb, and samples with nits were examined under a microscope in the laboratory. Cellophane tape and stool samples obtained from the participants were examined on the same day using the native-lugol, flotation, and trichrome staining methods under a light microscope (x10, x40, x100).
RESULTS
Five hundred sixty-three children were evaluated for head lice and 15 (2.6%) were found to be positive. During the examination, only nits were found in 11 students (1.9%), and both adult lice and nymphs were seen in 4 students (0.7%). Head lice were found positive in 2 out of 269 boys (0.7%), while 13 out of 294 girls (4.2%) positive (p<0.05). As a result of stool examination in children, was found in 11 (1.95%), in 4 (0.71%), sp. in 14 (2.48%), in 8 (1.42%) and spp. in 2 (0.35%). Head lice infestation and spp. were found to coexist in 2 (0.35%) children.
CONCLUSION
In conclusion, although there has been a noticeable decrease in head lice and intestinal parasites among primary school-aged children in Sivas province, these conditions are still present, as evidenced by previous studies conducted in our region.
Topics: Adult; Male; Child; Female; Animals; Humans; Pediculus; Lice Infestations; Parasites; Intestinal Diseases, Parasitic; Schools
PubMed: 38449365
DOI: 10.4274/tpd.galenos.2023.04796 -
Parasites & Vectors Jun 2023Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The...
BACKGROUND
Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The potential role of hippoboscids as vectors of human and veterinary pathogens is being increasingly investigated, but the presence and distribution of infectious agents in louse flies is still unknown in parts of Europe. Here, we report the use of molecular genetics to detect and characterize vector-borne pathogens in hippoboscid flies infesting domestic and wild animals in Austria.
METHODS
Louse flies were collected from naturally infested cattle (n = 25), sheep (n = 3), and red deer (n = 12) across Austria between 2015 and 2019. Individual insects were morphologically identified to species level and subjected to DNA extraction for molecular pathogen screening and barcoding. Genomic DNA from each louse fly was screened for Borrelia spp., Bartonella spp., Trypanosomatida, Anaplasmataceae, Filarioidea and Piroplasmida. Obtained sequences of Trypanosomatida and Bartonella spp. were further characterized by phylogenetic and haplotype networking analyses.
RESULTS
A total of 282 hippoboscid flies corresponding to three species were identified: Hippobosca equina (n = 62) collected from cattle, Melophagus ovinus (n = 100) from sheep and Lipoptena cervi (n = 120) from red deer (Cervus elaphus). Molecular screening revealed pathogen DNA in 54.3% of hippoboscids, including infections with single (63.39%), two (30.71%) and up to three (5.90%) distinct pathogens in the same individual. Bartonella DNA was detected in 36.9% of the louse flies. Lipoptena cervi were infected with 10 distinct and previously unreported Bartonella sp. haplotypes, some closely associated with strains of zoonotic potential. DNA of trypanosomatids was identified in 34% of hippoboscids, including the first description of Trypanosoma sp. in H. equina. Anaplasmataceae DNA (Wolbachia spp.) was detected only in M. ovinus (16%), while < 1% of the louse flies were positive for Borrelia spp. and Filarioidea. All hippoboscids were negative for Piroplasmida.
CONCLUSIONS
Molecular genetic screening confirmed the presence of several pathogens in hippoboscids infesting domestic and wild ruminants in Austria, including novel pathogen haplotypes of zoonotic potential (e.g. Bartonella spp.) and the first report of Trypanosoma sp. in H. equina, suggesting a potential role of this louse fly as vector of animal trypanosomatids. Experimental transmission studies and expanded monitoring of hippoboscid flies and hippoboscid-associated pathogens are warranted to clarify the competence of these ectoparasites as vectors of infectious agents in a One-Health context.
Topics: Humans; Animals; Sheep; Cattle; Diptera; Deer; Austria; Phylogeny; Ruminants; Bartonella; Anoplura; Anaplasmataceae; Piroplasmida
PubMed: 37269018
DOI: 10.1186/s13071-023-05810-4 -
PloS One 2023The human louse, Pediculus humanus, is an obligate blood-sucking ectoparasite that has coevolved with humans for millennia. Given the intimate relationship between this...
The human louse, Pediculus humanus, is an obligate blood-sucking ectoparasite that has coevolved with humans for millennia. Given the intimate relationship between this parasite and the human host, the study of human lice has the potential to shed light on aspects of human evolution that are difficult to interpret using other biological evidence. In this study, we analyzed the genetic variation in 274 human lice from 25 geographic sites around the world by using nuclear microsatellite loci and female-inherited mitochondrial DNA sequences. Nuclear genetic diversity analysis revealed the presence of two distinct genetic clusters I and II, which are subdivided into subclusters: Ia-Ib and IIa-IIb, respectively. Among these samples, we observed the presence of the two most common louse mitochondrial haplogroups: A and B that were found in both nuclear Clusters I and II. Evidence of nuclear admixture was uncommon (12%) and was predominate in the New World potentially mirroring the history of colonization in the Americas. These findings were supported by novel DIYABC simulations that were built using both host and parasite data to define parameters and models suggesting that admixture between cI and cII was very recent. This pattern could also be the result of a reproductive barrier between these two nuclear genetic clusters. In addition to providing new evolutionary knowledge about this human parasite, our study could guide the development of new analyses in other host-parasite systems.
Topics: Animals; Humans; Female; Pediculus; Phylogeny; Lice Infestations; DNA, Mitochondrial; Genetic Variation
PubMed: 37939041
DOI: 10.1371/journal.pone.0293409 -
PeerJ 2023Following school closures and changes in contact behavior of children and adults a reduced head louse prevalence has been reported from across the globe. In parallel,...
Following school closures and changes in contact behavior of children and adults a reduced head louse prevalence has been reported from across the globe. In parallel, sales of treatments were observed to fall, partly because of supply problems of some products following the pandemic, but this did not appear to result in more cases of infestation. Surveys of schools in and around Cambridge, UK, found that infestation rates were significantly reduced particularly in city schools compared with similar surveys conducted before the COVID-19 pandemic. Contrary to expectation the number of cases in schools has only risen slowly since schools returned to normal full time working in 2022-2023.
Topics: Adult; Child; Animals; Humans; Pediculus; Pandemics; Prevalence; COVID-19; Lice Infestations; United Kingdom
PubMed: 37701830
DOI: 10.7717/peerj.16001 -
Turkiye Parazitolojii Dergisi Dec 2023The aim of the study is to determine the prevalence rates of ectoparasites (external parasites) seen in cattle in Muğla, Aydın and İzmir regions.
OBJECTIVE
The aim of the study is to determine the prevalence rates of ectoparasites (external parasites) seen in cattle in Muğla, Aydın and İzmir regions.
METHODS
For ectoparasite screening, a total of 1,353 cattle breeds from Muğla, Aydın and İzmir regions were included in the study. Ectoparasite samples were collected with the help of hand, forceps, comb and scalpel, brought to the laboratory in plastic containers containing 70% alcohol and examined under a microscope.
RESULTS
In the study, 191 (14.12%) of 1,353 cattle were infested with external parasites. Of the cattle, 138 (72.25%) ticks, 24 (12.57%) lice, 9 (4.71%) tabanid, 8 (4.19%) hippoboscid, 7 (3.66%) fleas and 5 (2.62%) mites were detected. Accordingly, 4 tick species in cattle , 4 lice species ( ), 1 mite species (), 2 flea species (), 1 hippoboscid fly species () ve 3 tabanid fly species () diagnosed.
CONCLUSION
The presence of external parasites varied depending on the frequency of antiparasitic use in cattle.
Topics: Animals; Cattle; Prevalence; Anoplura; Flea Infestations; Ticks; Mites; Siphonaptera; Ixodidae; Diptera
PubMed: 38149447
DOI: 10.4274/tpd.galenos.2023.18209 -
Turkiye Parazitolojii Dergisi Jun 2023Head lice infestation (HLI), caused by , is an important public health problem worldwide, especially in primary school children. The aim of this study is to investigate...
OBJECTIVE
Head lice infestation (HLI), caused by , is an important public health problem worldwide, especially in primary school children. The aim of this study is to investigate HLI level, related factors, and families' knowledge levels and attitudes about HLI in two primary schools in a relatively low socio-economic region in İstanbul.
METHODS
A questionnaire on HLI was developed initially and delivered to all children and parents in the school. A total of 340 primary school students, aged between 6-12, were enrolled in the study after the consent of their parents. Their hair were examined for HLI with special combs at their schools, and free anti-lice shampoos were given to parents of positive children. A total of 951 completed questionnaires were received and evaluated with chi-square test using the SPSS 17.0 program, and the differences of p<0.05 were considered significant.
RESULTS
Number of boys in the study was slightly higher than the girls (176 vs. 164). HLI was detected in 32 (9.4%) of 340 children; seven had live adult lice on their hair while 25 had only the nits. HLI was obviously more common in girls (16.4%), compared to boys (2.8%). Analysis of 951 questionnaires revealed a statistically significant difference between HLI and infrequent bathing (p<0.05). The differences between HLI and the education levels of parents, income, the number of siblings and in contact with animals were not found to be significant (p>0.05).
CONCLUSION
HLI is still a common health problem, especially in girls in primary schools. Parents are aware of the relationship between the hygiene and prevention against HLI, but low socio-economic resources seem to be important determinants. Regular combing and training activities in primary schools, in coordination with the local authorities and parents are no doubt useful in reducing the incidence of HLI among the children.
Topics: Animals; Lice Infestations; Prevalence; Pediculus; Schools; Epidemiologic Studies; Scalp Dermatoses
PubMed: 37249115
DOI: 10.4274/tpd.galenos.2023.84803 -
Molecular Biology and Evolution Apr 2024Insects have repeatedly forged symbioses with heritable microbes, gaining novel traits. For the microbe, the transition to symbioses can lead to the degeneration of the...
Insects have repeatedly forged symbioses with heritable microbes, gaining novel traits. For the microbe, the transition to symbioses can lead to the degeneration of the symbiont's genome through transmission bottlenecks, isolation, and the loss of DNA repair enzymes. However, some insect-microbial symbioses have persisted for millions of years, suggesting that natural selection slows genetic drift and maintains functional consistency between symbiont populations. By sampling in multiple countries, we examine genomic diversity within a symbiont species, a heritable symbiotic bacterium found only in human head lice. We find that human head louse symbionts contain genetic diversity that appears to have arisen contemporaneously with the appearance of anatomically modern humans within Africa and/or during the colonization of Eurasia by humans. We predict that the observed genetic diversity underlies functional differences in extant symbiont lineages, through the inactivation of genes involved in symbiont membrane construction. Furthermore, we find evidence of additional gene losses prior to the appearance of modern humans, also impacting the symbiont membrane. From this, we conclude that symbiont genome degeneration is proceeding, via gene inactivation and subsequent loss, in human head louse symbionts, while genomic diversity is maintained. Collectively, our results provide a look into the genomic diversity within a single symbiont species and highlight the shared evolutionary history of humans, lice, and bacteria.
Topics: Animals; Humans; Pediculus; Phylogeny; Genome, Bacterial; Evolution, Molecular; Bacteria; Genomics; Hominidae; Insecta; Symbiosis
PubMed: 38513084
DOI: 10.1093/molbev/msae064 -
International Journal of Infectious... Jan 2024
Topics: Animals; Humans; Phthiraptera; Scalp; Hair; Lice Infestations; Pediculus
PubMed: 37977502
DOI: 10.1016/j.ijid.2023.11.017