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Immunologic Research Aug 2014Parasitic diseases are a serious global health concern. Many of the most common and most severe parasitic diseases, including Chagas' disease, leishmaniasis, and... (Review)
Review
Parasitic diseases are a serious global health concern. Many of the most common and most severe parasitic diseases, including Chagas' disease, leishmaniasis, and schistosomiasis, are also classified as neglected tropical diseases and are comparatively less studied than infectious diseases prevalent in high income nations. The NLRs (nucleotide-binding domain leucine-rich-repeat-containing proteins) are cytosolic proteins known to be involved in pathogen detection and host response. The role of NLRs in the host response to parasitic infection is just beginning to be understood. The NLR proteins NOD1 and NOD2 have been shown to contribute to immune responses during Trypanosoma cruzi infection, Toxoplasma gondii infection, and murine cerebral malaria. The NLRP3 inflammasome is activated by T. cruzi and Leishmania amazonensis but also induces pathology during infection with schistosomes or malaria. Both the NLRP1 and NLRP3 inflammasomes respond to T. gondii infection. The NLRs may play crucial roles in human immune responses during parasitic infection, usually acting as innate immune sensors and driving the inflammatory response against invading parasites. However, this inflammatory response can either kill the invading parasite or be responsible for destructive pathology. Therefore, understanding the role of the NLR proteins will be critical to understanding the host defense against parasites as well as the fine balance between homeostasis and parasitic disease.
Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis Regulatory Proteins; Carrier Proteins; Humans; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; NLR Proteins; Nod1 Signaling Adaptor Protein; Nod2 Signaling Adaptor Protein; Portraits as Topic; Protozoan Infections
PubMed: 24989828
DOI: 10.1007/s12026-014-8544-x -
Parasitology Dec 2022Finfish aquaculture in freshwater and marine environments is continuously expanding globally, and the potential for a substantial further increase is well documented.... (Review)
Review
Finfish aquaculture in freshwater and marine environments is continuously expanding globally, and the potential for a substantial further increase is well documented. The industry is supplying fish products for human consumption to the same extent as capture fisheries, and new fish species for domestication are still being selected by the industry. The challenge faced by all aquacultured species, classical and novel, is the range of pathogens associated with each new fish type. A fish host in its natural environment carries a series of more or less specific parasites (specialists and generalists). Some of these show a marked ability to propagate in aquaculture settings. They may then elicit disease when infection intensities in the confined aquaculture environment reach high levels. In addition, the risk of transmission of parasites from aquaculture enterprises to wild fish stocks adds to the parasitic challenge. Control programmes of various kinds are needed and these may include chemotherapeutants and medicines as the farmer's first and convenient choice, but mechanical, biological, immunological and genetic control methods are available solutions. New methods are still to be developed by scrutinizing the life cycle of each particular parasite species and pin-pointing the vulnerable stage to be targeted. As parasites exhibit a huge potential for adaptation to environmental changes, one must realize that only one approach rarely is sufficient. The present work therefore elaborates on and advocates for implementation of integrated control strategies for diseases caused by protozoan and metazoan parasites.
Topics: Animals; Humans; Fish Diseases; Aquaculture; Fisheries; Fishes; Parasites; Parasitic Diseases
PubMed: 35950444
DOI: 10.1017/S0031182022001093 -
Frontiers in Immunology 2021Neuroinflammation is one of the most frequently studied topics of neurosciences as it is a common feature in almost all neurological disorders. Although the primary... (Review)
Review
Neuroinflammation is one of the most frequently studied topics of neurosciences as it is a common feature in almost all neurological disorders. Although the primary function of neuroinflammation is to protect the nervous system from an insult, the complex and sequential response of activated glial cells can lead to neurological damage. Depending on the type of insults and the time post-insult, the inflammatory response can be neuroprotective, neurotoxic, or, depending on the glial cell types, both. There are multiple pathways activated and many bioactive intermediates are released during neuroinflammation. One of the most common one is the kynurenine pathway, catabolizing tryptophan, which is involved in immune regulation, neuroprotection, and neurotoxicity. Different models have been used to study the kynurenine pathway metabolites to understand their involvements in the development and maintenance of the inflammatory processes triggered by infections. Among them, the parasitic infection could be used as a relevant model to study the role of the kynurenine pathway in the neuroinflammatory response and the subset of cells involved.
Topics: Animals; Humans; Inflammation; Kynurenine; Neospora; Nervous System Diseases; Parasitic Diseases; Signal Transduction
PubMed: 35154065
DOI: 10.3389/fimmu.2021.714248 -
Trends in Parasitology Dec 2020Wildlife vaccination is of urgent interest to reduce disease-induced extinction and zoonotic spillover events. However, several challenges complicate its application to... (Review)
Review
Wildlife vaccination is of urgent interest to reduce disease-induced extinction and zoonotic spillover events. However, several challenges complicate its application to wildlife. For example, vaccines rarely provide perfect immunity. While some protection may seem better than none, imperfect vaccination can present epidemiological, ecological, and evolutionary challenges. While anti-infection and antitransmission vaccines reduce parasite transmission, antidisease vaccines may undermine herd immunity, select for increased virulence, or promote spillover. These imperfections interact with ecological and logistical constraints that are magnified in wildlife, such as poor control and substantial trait variation within and among species. Ultimately, we recommend approaches such as trait-based vaccination, modeling tools, and methods to assess community- and ecosystem-level vaccine safety to address these concerns and bolster wildlife vaccination campaigns.
Topics: Animals; Animals, Wild; Biological Evolution; Ecosystem; Parasitic Diseases, Animal; Vaccination; Vaccines
PubMed: 32952060
DOI: 10.1016/j.pt.2020.08.006 -
International Journal of Infectious... Jul 2020Parasitic infections of the eye are a major cause of ocular-surface diseases globally. While most infections are treatable, parasites can cause varying levels of damage...
INTRODUCTION
Parasitic infections of the eye are a major cause of ocular-surface diseases globally. While most infections are treatable, parasites can cause varying levels of damage mostly due to late diagnosis or misdiagnosis as a result of doctors' unfamiliarity with their characteristics of latency and crypsis, as well as lack of awareness by the patients.
CASE REPORTS
In this study, we present three cases of phthiriasis palpebrarum, thelaziasis, and ophthalmomyiasis, respectively. Two of the cases were treated at the clinic and did not recur. One patient refused treatment and was lost to follow-up.
DISCUSSION
By evaluating the natural histories, morphology, symptoms, clinical findings, and treatment of these parasitic diseases, we systematically analyzed several distinct and unique parasite characteristics, especially latency and crypsis. Furthermore, we have proposed specific examination techniques and methods as well as prevention and treatment strategies from these specific perspectives, aiming to prompt timely diagnoses and early interventions for these diseases by health care workers and improve the public's awareness of parasitic infections.
CONCLUSION
Parasitosis on the ocular surface is a global infectious disease, and prevention strategies include maintaining personal and environmental hygiene and limiting contact with animals. We recommend that health care workers should enhance their ability to detect and diagnose these diseases while promoting the public's awareness of them in the context of our new perspectives.
Topics: Aged, 80 and over; Animals; Child; Delayed Diagnosis; Diagnostic Errors; Eye Infections, Parasitic; Eyelashes; Female; Humans; Lice Infestations; Male; Middle Aged; Myiasis; Phthirus; Recurrence; Spirurida Infections; Thelazioidea
PubMed: 32447120
DOI: 10.1016/j.ijid.2020.05.061 -
Experimental Biology and Medicine... Oct 2022Parasitic infections acquired by the population cause substantial morbidity worldwide, with individuals from developing countries being most affected. Some parasites... (Review)
Review
Parasitic infections acquired by the population cause substantial morbidity worldwide, with individuals from developing countries being most affected. Some parasites remain in the host for long periods, settling in different organs, manipulating the flow of nutrients and metabolites, and influencing the immune response, favoring their adaptation. The host attempts to counteract the metabolic and immunological alterations and the possible damage caused by infection. These metabolic and immunological changes experienced by the host can influence the progression of other existing morbidities or those that will be acquired in the future. Cancer and metabolic diseases are also frequent causes of morbidity in the world population. The large numbers of individuals affected by cancer and metabolic diseases and the high prevalence of morbidity caused by parasitic diseases favor the development of comorbidity involving these pathologies. This review provides an overview of major advances in research on cancer and metabolic diseases associated with parasitic infections. Information about hosts and parasites such as alterations of the immune response, metabolism and adaptation mechanisms of the parasites, and parasitic molecules with therapeutic potential is provided, as well as the beneficial results or complications related to the comorbidities discussed herein. We emphasize the need to conduct additional studies addressing comorbidities associated with parasitic infections to improve the understanding of the impact of this association on the progression of morbidities, as well as the possibility of the therapeutic use of and therapeutic approaches involving parasites.
Topics: Animals; Humans; Parasitic Diseases; Parasites; Comorbidity; Prevalence
PubMed: 35876147
DOI: 10.1177/15353702221108387 -
Parasites & Vectors Jun 2021Parasites, including viruses, bacteria, fungi, protists, helminths, and arthropods, are ubiquitous in the animal kingdom. Consequently, hosts are frequently infected... (Review)
Review
Parasites, including viruses, bacteria, fungi, protists, helminths, and arthropods, are ubiquitous in the animal kingdom. Consequently, hosts are frequently infected with more than one parasite species simultaneously. The assessment of such co-infections is of fundamental importance for disease ecology, but relevant studies involving non-domesticated animals have remained scarce. Many amphibians are in decline, and they generally have a highly diverse parasitic fauna. Here we review the literature reporting on field surveys, veterinary case studies, and laboratory experiments on co-infections in amphibians, and we summarize what is known about within-host interactions among parasites, which environmental and intrinsic factors influence the outcomes of these interactions, and what effects co-infections have on hosts. The available literature is piecemeal, and patterns are highly diverse, so that identifying general trends that would fit most host-multiparasite systems in amphibians is difficult. Several examples of additive, antagonistic, neutral, and synergistic effects among different parasites are known, but whether members of some higher taxa usually outcompete and override the effects of others remains unclear. The arrival order of different parasites and the time lag between exposures appear in many cases to fundamentally shape competition and disease progression. The first parasite to arrive can gain a marked reproductive advantage or induce cross-reaction immunity, but by disrupting the skin and associated defences (i.e., skin secretions, skin microbiome) and by immunosuppression, it can also pave the way for subsequent infections. Although there are exceptions, detrimental effects to the host are generally aggravated with increasing numbers of co-infecting parasite species. Finally, because amphibians are ectothermic animals, temperature appears to be the most critical environmental factor that affects co-infections, partly via its influence on amphibian immune function, partly due to its direct effect on the survival and growth of parasites. Besides their importance for our understanding of ecological patterns and processes, detailed knowledge about co-infections is also crucial for the design and implementation of effective wildlife disease management, so that studies concentrating on the identified gaps in our understanding represent rewarding research avenues.
Topics: Amphibians; Animals; Animals, Wild; Coinfection; Host-Parasite Interactions; Parasites; Parasitic Diseases, Animal
PubMed: 34082796
DOI: 10.1186/s13071-021-04796-1 -
Handbook of Experimental Pharmacology 2015During infection significant alterations in lipid metabolism and lipoprotein composition occur. Triglyceride and VLDL cholesterol levels increase, while reduced HDL... (Review)
Review
During infection significant alterations in lipid metabolism and lipoprotein composition occur. Triglyceride and VLDL cholesterol levels increase, while reduced HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) levels are observed. More importantly, endotoxemia modulates HDL composition and size: phospholipids are reduced as well as apolipoprotein (apo) A-I, while serum amyloid A (SAA) and secretory phospholipase A2 (sPLA2) dramatically increase, and, although the total HDL particle number does not change, a significant decrease in the number of small- and medium-size particles is observed. Low HDL-C levels inversely correlate with the severity of septic disease and associate with an exaggerated systemic inflammatory response. HDL, as well as other plasma lipoproteins, can bind and neutralize Gram-negative bacterial lipopolysaccharide (LPS) and Gram-positive bacterial lipoteichoic acid (LTA), thus favoring the clearance of these products. HDLs are emerging also as a relevant player during parasitic infections, and a specific component of HDL, namely, apoL-1, confers innate immunity against trypanosome by favoring lysosomal swelling which kills the parasite. During virus infections, proteins associated with the modulation of cholesterol bioavailability in the lipid rafts such as ABCA1 and SR-BI have been shown to favor virus entry into the cells. Pharmacological studies support the benefit of recombinant HDL or apoA-I mimetics during bacterial infection, while apoL-1-nanobody complexes were tested for trypanosome infection. Finally, SR-BI antagonism represents a novel and forefront approach interfering with hepatitis C virus entry which is currently tested in clinical studies. From the coming years, we have to expect new and compelling observations further linking HDL to innate immunity and infections.
Topics: Animals; Bacterial Infections; Biomarkers; Host-Parasite Interactions; Host-Pathogen Interactions; Humans; Lipoproteins, HDL; Parasitic Diseases; Sepsis; Virus Diseases
PubMed: 25522999
DOI: 10.1007/978-3-319-09665-0_15 -
Trends in Parasitology Jun 2017Ivermectin is one of the most important drugs in veterinary and human medicine for the control of parasitic infection and was the joint focus of the 2015 Nobel Prize in... (Review)
Review
Ivermectin is one of the most important drugs in veterinary and human medicine for the control of parasitic infection and was the joint focus of the 2015 Nobel Prize in Physiology or Medicine, some 35 years after its remarkable discovery. Although best described for its activity on glutamate-gated chloride channels in parasitic nematodes, understanding of its mode of action remains incomplete. In the field of veterinary medicine, resistance to ivermectin is now widespread, but the mechanisms underlying resistance are unresolved. Here we discuss the history of this versatile drug and its use in global health. Based on recent studies in a variety of systems, we question whether ivermectin could have additional modes of action on parasitic nematodes.
Topics: Animals; Drug Resistance; History, 20th Century; History, 21st Century; Ivermectin; Parasitic Diseases
PubMed: 28285851
DOI: 10.1016/j.pt.2017.02.004 -
Frontiers in Immunology 2021Protozoan parasite infection causes severe diseases in humans and animals, leading to tremendous economic and medical pressure. Natural immunity is the first line of... (Review)
Review
Protozoan parasite infection causes severe diseases in humans and animals, leading to tremendous economic and medical pressure. Natural immunity is the first line of defence against parasitic infection. Currently, the role of natural host immunity in combatting parasitic infection is unclear, so further research on natural host immunity against parasites will provide a theoretical basis for the prevention and treatment of related parasitic diseases. Extracellular traps (ETs) are an important natural mechanism of immunity involving resistance to pathogens. When immune cells such as neutrophils and macrophages are stimulated by external pathogens, they release a fibrous network structure, consisting mainly of DNA and protein, that can capture and kill a variety of extracellular pathogenic microorganisms. In this review, we discuss the relevant recently reported data on ET formation induced by protozoan parasite infection, including the molecular mechanisms involved, and discuss the role of ETs in the occurrence and development of parasitic diseases.
Topics: Animals; Extracellular Traps; Host-Parasite Interactions; Humans; Immunity, Innate; Leishmania; Neutrophils; Plasmodium; Protozoan Infections; Protozoan Infections, Animal; Signal Transduction; Toxoplasma
PubMed: 34970259
DOI: 10.3389/fimmu.2021.770246