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Trends in Parasitology Jun 2009For human, domestic animal and wildlife health, key effects of directional climate change include the risk of the altered occurrence of infectious diseases. Many... (Review)
Review
For human, domestic animal and wildlife health, key effects of directional climate change include the risk of the altered occurrence of infectious diseases. Many parasite zoonoses have high potential for vulnerability to the new climate, in part because their free-living life-cycle stages and ectothermic hosts are directly exposed to climatic conditions. For these zoonoses, climate change can shift boundaries for ecosystem components and processes integral to parasite transmission and persistence, and these shifts can impact host health. Vulnerable boundaries include those for spatial distributions, host-parasite assemblages, demographic rates, life-cycle phenologies, associations within ecosystems, virulence, and patterns of infection and disease. This review describes these boundary shifts and how molecular techniques can be applied to defining the new boundaries.
Topics: Animals; Ecosystem; Greenhouse Effect; Host-Parasite Interactions; Humans; Molecular Biology; Parasites; Parasitic Diseases; Prevalence; Zoonoses
PubMed: 19428303
DOI: 10.1016/j.pt.2009.03.007 -
Trends in Parasitology Dec 2013With the development of new technologies in genome sequencing, gene expression profiling, genotyping, and high-throughput screening of chemical compound libraries, small... (Review)
Review
With the development of new technologies in genome sequencing, gene expression profiling, genotyping, and high-throughput screening of chemical compound libraries, small molecules are playing increasingly important roles in studying gene expression regulation, gene-gene interaction, and gene function. Here we briefly review and discuss some recent advancements in drug target identification and phenotype characterization using combinations of high-throughput screening of small-molecule libraries and various genome-wide methods such as whole-genome sequencing, genome-wide association studies (GWAS), and genome-wide expression analysis. These approaches can be used to search for new drugs against parasite infections, to identify drug targets or drug resistance genes, and to infer gene function.
Topics: Animals; Genomics; High-Throughput Screening Assays; Mutation; Parasites; Parasitology; Phenotype; Small Molecule Libraries; Transcriptome
PubMed: 24215777
DOI: 10.1016/j.pt.2013.10.005 -
Clinical Microbiology and Infection :... Dec 2019Parasitic infections are responsible for a significant burden of disease worldwide as a result of international travel and immigration. More accurate diagnostic tools... (Review)
Review
BACKGROUND
Parasitic infections are responsible for a significant burden of disease worldwide as a result of international travel and immigration. More accurate diagnostic tools are necessary in support to parasite control and elimination programmes in endemic regions as well as for rapid case detection in non-endemic areas. Digital PCR (dPCR) is a powerful technology with recent applications in parasitology.
AIMS
This review provides for the first time an overview of dPCR as a novel technology applied to detection of parasitic infections, and highlights the most relevant potential benefits of this assay.
SOURCES
Peer-reviewed literature pertinent to this review based on PubMed, Cochrane and Embase databases as well as laboratory experience of authors.
CONTENT
Among the 86 studies retrieved, 17 used the dPCR applied to parasites belonging to protozoa (8), helminths (8) and arthropods (1) of clinical human interest. dPCR was adopted in four studies, respectively, for Plasmodium and Schistosoma japonicum. dPCR led to clear advantages over quantitative real-time PCR in P. falciparum and spp., and in S. japonicum showing higher sensitivity; and in Cryptosporidium with higher stability to inhibitors from stool. For all parasites, dPCR allows absolute quantitation without the need of a standard curve. Various dPCR platforms were used. A few critical factors need consideration: DNA load, choice of platform and reaction optimization.
IMPLICATIONS
Owing to its sensitivity and quantitative characteristics, dPCR is a potential candidate to become an appealing new method among the molecular technologies for parasite detection and quantitative analysis in the future. In general, it has more applications than genomic DNA detection only, such as quantitation in mixed infections, gene expression and mutation analysis. dPCR should be considered in malaria screening and diagnosis as a complement to routine assays and in schistosomiasis elimination programmes. Standardized strategies and further studies are needed for the integration of dPCR in routine clinical laboratory.
Topics: Animals; Diagnostic Tests, Routine; Humans; Mass Screening; Microfluidic Analytical Techniques; Molecular Diagnostic Techniques; Parasites; Parasitic Diseases; Parasitology; Polymerase Chain Reaction
PubMed: 31226445
DOI: 10.1016/j.cmi.2019.06.009 -
Clinical Microbiology and Infection :... Mar 2019Parasitic diseases are one of the world's most devastating and prevalent infections, causing millions of morbidities and mortalities annually. In the past, many of these... (Review)
Review
BACKGROUND
Parasitic diseases are one of the world's most devastating and prevalent infections, causing millions of morbidities and mortalities annually. In the past, many of these infections have been linked predominantly to tropical or subtropical areas. Nowadays, however, climatic and vector ecology changes, a significant increase in international travel, armed conflicts, and migration of humans and animals have influenced the transmission of some parasitic diseases from 'book pages' to reality in developed countries. It has also been noted that many patients who have never travelled to endemic areas suffer from blood-borne infections caused by protozoa. In the light of existing knowledge, this new trend can be explained by the fact that in the process of migration a large number of asymptomatic carriers become a part of the blood bank donor and transplant donor populations. Accurate and rapid diagnosis represents the crucial weapon in the fight against parasitic infections.
AIMS
To review old and new approaches for rapid diagnosis of parasitic infections.
SOURCES
Data for this review were obtained through searches of PubMed using combinations of the following terms: parasitological diagnostics, microscopy, lateral flow assays, immunochromatographic assays, multiplex-PCR, and transplantation.
CONTENT
In this review, we provide a brief account of the advantages and limitations of rapid methods for diagnosis of parasitic diseases and focus our attention on current and future research in this area. The approximate costs associated with the use of different techniques and their applicability in endemic and non-endemic areas are also discussed.
IMPLICATIONS
Microscopy remains the cornerstone of parasitological diagnostics, especially in the field and low-resource settings, and provides epidemiological assessment of parasite burden. However, increased use and availability of point-of-care tests and molecular assays in modern era allow more rapid and accurate diagnoses and increased sensitivity in the identification of parasitic infections.
Topics: Animals; Diagnostic Tests, Routine; Humans; Microscopy; Molecular Diagnostic Techniques; Parasites; Parasitic Diseases; Parasitology; Point-of-Care Testing
PubMed: 29730224
DOI: 10.1016/j.cmi.2018.04.028 -
Philosophical Transactions of the Royal... Aug 2015Variation among parasite strains can affect the progression of disease or the effectiveness of treatment. What maintains parasite diversity? Here I argue that... (Review)
Review
Variation among parasite strains can affect the progression of disease or the effectiveness of treatment. What maintains parasite diversity? Here I argue that competition among parasites within the host is a major cause of variation among parasites. The competitive environment within the host can vary depending on the parasite genotypes present. For example, parasite strategies that target specific competitors, such as bacteriocins, are dependent on the presence and susceptibility of those competitors for success. Accordingly, which parasite traits are favoured by within-host selection can vary from host to host. Given the fluctuating fitness landscape across hosts, genotype by genotype (G×G) interactions among parasites should be prevalent. Moreover, selection should vary in a frequency-dependent manner, as attacking genotypes select for resistance and genotypes producing public goods select for cheaters. I review competitive coexistence theory with regard to parasites and highlight a few key examples where within-host competition promotes diversity. Finally, I discuss how within-host competition affects host health and our ability to successfully treat infectious diseases.
Topics: Animals; Genetic Variation; Host-Parasite Interactions; Humans; Models, Biological; Parasites; Parasitic Diseases
PubMed: 26150667
DOI: 10.1098/rstb.2014.0301 -
Biological Reviews of the Cambridge... Nov 2009Parasitism is a common cause of host mortality, but little is known about the ecological factors affecting parasite virulence (the rate of mortality among infected... (Meta-Analysis)
Meta-Analysis Review
Parasitism is a common cause of host mortality, but little is known about the ecological factors affecting parasite virulence (the rate of mortality among infected hosts). We reviewed 117 field estimates of parasite-induced nestling mortality in birds, showing that there was significant consistency in mortality among host and parasite taxa. Virulence increased towards the tropics in analyses of both species-specific data and phylogenetic analyses. We found evidence of greater parasite prevalence being associated with reduced virulence. Furthermore, bird species breeding in open nest sites suffered from greater parasite-induced mortality than hole-nesting species. By contrast, parasite specialization and generation time of parasites relative to that of hosts explained little variation in virulence. Likewise, there were little or no significant effects of host genetic variability, host sociality, host migration, host insular distribution or host survival on parasite virulence. These findings suggest that parasite-induced nestling mortality in birds is mainly determined by geographical location and to a smaller extent nest site and prevalence.
Topics: Animals; Bird Diseases; Birds; Parasites; Parasitic Diseases, Animal; Virulence
PubMed: 19673856
DOI: 10.1111/j.1469-185X.2009.00087.x -
International Journal For Parasitology Mar 2023The type of habitat occupied by avian populations has a marked effect on the parasitises they host. The growth of cities and urban areas in recent decades has favoured... (Comparative Study)
Comparative Study
The type of habitat occupied by avian populations has a marked effect on the parasitises they host. The growth of cities and urban areas in recent decades has favoured some species of birds adapted to these types of habitats - urban exploiters - although the effects of urbanisation on the parasitism of wildlife are not always well known. This study compares the ectoparasites characteristic of two differentiated populations of woodpigeons, one located in a predominantly urban environment and the other in a rural one. Most of the species found were chewing lice, with Columbicola claviformis and Campanulotes bidentatus being dominant. Despite the higher density of the urban population, woodpigeon individuals were characterised by a lower abundance of chewing lice, as well as the presence of ectoparasites typical of feral pigeons such as Hohorstiella lata and the hippoboscids fly, Pseudolynchia canariensis. Similarly, birds with lower weights showed a higher parasitic load, which became more noticeable in urban woodpigeons. The lower ectoparasite load of urban hosts represents a health advantage compared with rural populations, which could be one of the causes of greater growth and reproductive success in urban populations of woodpigeons.
Topics: Columbidae; Cities; Animals; Body Weight; Animals, Wild; Ischnocera; Ecosystem; Urbanization; Forests; Parasites
PubMed: 36690291
DOI: 10.1016/j.ijpara.2022.11.008 -
Parasite genomics and post-genomic activities: 21st century resources for the parasite immunologist.Parasite Immunology 2012
Topics: Animals; Genome; Genomics; Host-Parasite Interactions; Humans; Parasites; Parasitic Diseases
PubMed: 22103796
DOI: 10.1111/j.1365-3024.2011.01346.x -
Parasitology Jun 2007As a scientific discipline matures, its theoretical underpinnings tend to consolidate around a few general laws that explain a wide range of phenomena, and from which... (Review)
Review
As a scientific discipline matures, its theoretical underpinnings tend to consolidate around a few general laws that explain a wide range of phenomena, and from which can be derived further testable predictions. It is one of the goals of science to uncover the general principles that produce recurring patterns in nature. Although this has happened in many areas of physics and chemistry, ecology is yet to take this important step. Ecological systems are intrinsically complex, but this does not necessarily mean that everything about them is unpredictable or chaotic. Ecologists, whose grand aim is to understand the interactions that govern the distribution, abundance and diversity of living organisms at different scales, have uncovered several regular patterns, i.e. widely observable statistical tendencies, in the abundance or diversity of organisms in natural ecosystems. Some of these patterns, however, are contingent, i.e. they are only true under particular circumstances; nevertheless, the broad generality of many patterns hints at the existence of universal principles. What about parasite ecology: is it also characterized by recurring patterns and general principles? Evidence for repeatable empirical patterns in parasite ecology is reviewed here, in search of patterns that are consistently detectable across taxa or geographical areas. The coverage ranges from the population level all the way to large-scale patterns of parasite diversity and abundance (or biomass) and patterns in the structure of host-parasite interaction networks. Although general laws seem to apply to these extreme scales of studies, most patterns observed at the intermediate scale, i.e. the parasite community level, appear highly contingent and far from universal. The general laws uncovered to date are proving valuable, as they offer glimpses of the underlying processes shaping parasite ecology and diversity.
Topics: Animals; Biodiversity; Ecology; Host-Parasite Interactions; Parasites; Parasitology; Population
PubMed: 17234043
DOI: 10.1017/S0031182006002150 -
International Journal For Parasitology Oct 1996
Review
Topics: Animals; Body Constitution; Crustacea; Parasites; Parasitic Diseases; Parasitic Diseases, Animal; Trematoda
PubMed: 8982796
DOI: 10.1016/s0020-7519(96)80014-2