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Clinical Microbiology Reviews Oct 2017Cytauxzoonosis is an emerging infectious disease that affects wild felids as well as the domestic cat; it is caused by the apicomplexan protozoan parasites belonging to... (Review)
Review
Cytauxzoonosis is an emerging infectious disease that affects wild felids as well as the domestic cat; it is caused by the apicomplexan protozoan parasites belonging to the genus . is the species of major concern, whose transmission occurs via the bite of an infected tick. Cytauxzoonosis of the domestic cat has historically been considered uniformly fatal, with a short course of illness, and most domestic cats die within 9 to 15 days postinfection. However, increasing evidence of domestic cats surviving infection suggests the existence of different strains with various levels of pathogenicity. Although wild felids are considered natural reservoirs for this parasite, a number of studies suggest that domestic cats that have survived nonlethal infections may serve as an additional reservoir. The current article comprehensively reviews the parasite and its life cycle, geographic distribution, genetic variability, and pathogenesis, as well as host immunology and the diagnosis, treatment, and prevention of infection in the domestic cat. This information should provide a basis for better understanding the parasite as well as the pathogenesis of the disease.
Topics: Animals; Animals, Wild; Cat Diseases; Cats; Disease Reservoirs; Piroplasmida; Protozoan Infections, Animal; Ticks
PubMed: 28637681
DOI: 10.1128/CMR.00010-17 -
Journal of Feline Medicine and Surgery Nov 2015Cytauxzoonosis is a life-threatening hematoprotozoal disease with a rapidly progressive clinical course. Once considered a rare disease only relevant to a small... (Review)
Review
PRACTICAL RELEVANCE
Cytauxzoonosis is a life-threatening hematoprotozoal disease with a rapidly progressive clinical course. Once considered a rare disease only relevant to a small geographic area, it is now recognized in more than about a third of the United States. The geographic range seems likely to increase with expansion of the range of the vector tick.
CLINICAL CHALLENGES
Both disease diagnosis and treatment offer challenges. The acute illness is often recognized by characteristic parasitic cellular inclusions, but illness may occur before parasites can be identified, and parasitic inclusions may persist long after illness has resolved. Also, while infection was once considered nearly uniformly fatal, subclinical infections are now recognized. Disease prognosis has improved for many cats through implementation of new therapies, but some pathogens are resistant to these therapies and death from disease is still common. Currently, prevention strategies are limited to ectoparasite control.
GLOBAL IMPORTANCE
Cytauxzoonosis caused by Cytauxzoon felis is limited to the Americas, and is especially problematic in southeastern and south central USA. However, other Cytauxzoon species have been recognized in Europe and Asia.
AUDIENCE
This review is aimed at veterinary practitioners and focuses on the diagnosis and treatment of cytauxzoonosis. Disease management is of crucial importance in endemic regions. Furthermore, the expanding geographic range of infection, and the possibility of parasite identification in chronically infected cats with a travel history, make understanding cytauxzoonosis relevant in non-endemic regions as well.
EVIDENCE BASE
The authors draw on evidence from prospective clinical trials, experimental infections, retrospective clinical studies and case reports, as well as their own personal experience with the diagnosis and treatment of cytauxzoonosis.
Topics: Animal Welfare; Animals; Animals, Domestic; Asia; Cat Diseases; Cats; Disease Reservoirs; Europe; Prospective Studies; Protozoan Infections, Animal; Retrospective Studies; United States; Veterinary Medicine
PubMed: 26486980
DOI: 10.1177/1098612X15610681 -
Parasitology Research Feb 2016Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that... (Review)
Review
Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify the potentially relevant studies on protozoan parasitic infections and their implications in human and animal model infertility. Literature described that some of the protozoan parasites such as Trichomonas vaginalis may cause deformities of the genital tract, cervical neoplasia, and tubal and atypical pelvic inflammations in women and also non-gonoccocal urethritis, asthenozoospermia, and teratozoospermia in men. Toxopalasma gondii could cause endometritis, impaired folliculogenesis, ovarian and uterine atrophy, adrenal hypertrophy, vasculitis, and cessation of estrus cycling in female and also decrease in semen quality, concentration, and motility in male. Trypanosoma cruzi inhibits cell division in embryos and impairs normal implantation and development of placenta. Decrease in gestation rate, infection of hormone-producing glands, parasite invasion of the placenta, and overproduction of inflammatory cytokines in the oviducts and uterine horns are other possible mechanisms induced by Trypanosoma cruzi to infertility. Plasmodium spp. and Trypanosoma brucei spp. cause damage in pituitary gland, hormonal disorders, and decreased semen quality. Entamoeba histolytica infection leads to pelvic pain, salpingitis, tubo-ovarian abscess, and genital ulcers. Cutaneous and visceral leishmaniasis can induce genital lesion, testicular amyloidosis, inflammation of epididymis, prostatitis, and sperm abnormality in human and animals. In addition, some epidemiological studies have reported that rates of protozoan infections in infertile patients are higher than healthy controls. The current review indicates that protozoan parasitic infections may be an important cause of infertility. Given the widespread prevalence of parasitic protozoa diseases worldwide, we suggest further studies to better understanding of relationship between such infections and infertility.
Topics: Animals; Female; Humans; Infertility; Male; Pregnancy; Pregnancy Complications, Parasitic; Protozoan Infections; Semen
PubMed: 26573517
DOI: 10.1007/s00436-015-4827-y -
Veterinary Parasitology Feb 2015The protozoan flagellate Histomonas meleagridis is the etiological agent of histomonosis, first described in 1893. It is a fastidious disease in turkeys, with... (Review)
Review
The protozoan flagellate Histomonas meleagridis is the etiological agent of histomonosis, first described in 1893. It is a fastidious disease in turkeys, with pathological lesions in the caeca and liver, sometimes with high mortality. In chickens the disease is less fatal and lesions are often confined to the caeca. The disease was well controlled by applying nitroimidazoles and nitrofurans for therapy or prophylaxis. Since their introduction into the market in the middle of the previous century, research nearly ceased as outbreaks of histomonosis occurred only very rarely. With the ban of these drugs in the last two decades in North America, the European Union and elsewhere, in combination with the changes in animal husbandry, the disease re-emerged. Consequently, research programs were set up in various places focusing on different features of the parasite and the disease. For the first time studies were performed to elucidate the molecular repertoire of the parasite. In addition, research has been started to investigate the parasite's interaction with its host. New diagnostic methods and tools were developed and tested with samples obtained from field outbreaks or experimental infections. Some of these studies aimed to clarify the introduction of the protozoan parasite into a flock and the transmission between birds. Finally, a strong focus was placed on research concentrated on the development of new treatment and prophylactic strategies, urgently needed to combat the disease. This review aims to summarize recent research activities and place them into context with older literature.
Topics: Animals; Host-Parasite Interactions; Poultry Diseases; Protozoan Infections, Animal; Trichomonadida; Turkeys
PubMed: 25576442
DOI: 10.1016/j.vetpar.2014.12.018 -
Future Microbiology 2015The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products... (Review)
Review
The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products may contribute to the emergence of protozoan infections in nonendemic countries. Infections such as malaria are potentially fatal, especially in nonimmune patients, and outcome depends largely on timely diagnosis and treatment. Diagnosis/management of imported parasitic infections may be complex especially as some patients may have underlying immunosuppressive conditions such as HIV infection. Major challenges concern the development of improved diagnostic techniques, safer/more effective drug therapies and identification of biological markers of progression and response to treatment. Imported parasitic diseases which may be transmitted vertically or through blood transfusion/organ donation could become a public health priority in the near future. Climate change may affect arthropod distribution and facilitate the spread of protozoan vector-borne diseases. The first part of this review focuses on protozoan infections in travelers and immigrants.
Topics: Climate Change; Emigrants and Immigrants; Humans; Protozoan Infections; Public Health; Travel
PubMed: 25598338
DOI: 10.2217/fmb.14.105 -
Acta Veterinaria Scandinavica Jan 2020Abortion is a major source of economic losses in cattle breeding. Abortion occurs due to a wide range of causes, but infections are the most frequently diagnosed....
BACKGROUND
Abortion is a major source of economic losses in cattle breeding. Abortion occurs due to a wide range of causes, but infections are the most frequently diagnosed. However, establishing an aetiological diagnosis remains challenging due to the large variety of bacteria, protozoa, viruses, and fungi that have been associated with abortion in cattle. Economic restraints limit the range of diagnostic methods available for routine diagnostics, and decomposition of the conceptus or lack of proper fetal and/or maternal samples further restrict the diagnostic success. In this study, we report recent diagnostic findings from bovine abortions in Denmark, a country that has a large dairy sector and is free from most infectious agents causing epizootic abortion in cattle. The aims of the study were: (i) to identify infectious causes of bovine abortion in Denmark, (ii) to categorise the diagnostic findings based on the level of diagnostic certainty, and (iii) to assess the diagnostic rate. Due to economic restraints, only a limited panel of routine diagnostic methods were available. Placentas and/or fetuses from mid- to late-term abortions and stillbirths (n = 162) were submitted to the Danish National Veterinary Institute between January 2015 and June 2017. The aborted materials were examined macroscopically, histologically, and by bacterial culture. Maternal blood samples were tested for bovine viral diarrhoea virus (BVDV) antibodies.
RESULTS
The likely aetiology of the abortion was diagnosed in 52 cases, resulting in a diagnostic rate of 33%. The most common cause was protozoal infection (19%) followed by infection with Trueperella pyogenes (3%), Staphylococcus aureus (2%), and non-haemolytic Escherichia coli (2%). Lesions in fetuses with a protozoal infection were consistent with neosporosis. In many cases (38%), inflammatory changes were found in the placenta and/or fetal organs but no specific aetiology was identified. Neither infection with Brucella spp. nor maternal BVDV antibodies were detected. The majority of submitting herds (92%) were each represented by fewer than three abortion cases over the study period.
CONCLUSIONS
Protozoal infection, most likely neosporosis, was the most commonly diagnosed cause of abortion and the only one associated with potential epizootic abortion events. Despite using a reduced number of diagnostic methods in comparison to other abortion studies, the diagnostic rate of this study was within the range reported in an earlier Danish study, as well as in recent international studies. The low number of submitted cases per herd and the sparse anamnestic information provided at submission hampered conclusions on the potential epizootic character of the abortion events in question.
Topics: Abortion, Veterinary; Animals; Antibodies, Viral; Bacterial Infections; Cattle; Cattle Diseases; Denmark; Female; Fetus; Placenta; Pregnancy; Protozoan Infections, Animal
PubMed: 31900210
DOI: 10.1186/s13028-019-0499-4 -
International Journal of Molecular... Apr 2021Leishmaniasis, malaria, toxoplasmosis, and acanthamoebiasis are protozoan parasitic infections. They remain important contributors to the development of kidney disease,... (Review)
Review
Leishmaniasis, malaria, toxoplasmosis, and acanthamoebiasis are protozoan parasitic infections. They remain important contributors to the development of kidney disease, which is associated with increased patients' morbidity and mortality. Kidney injury mechanisms are not fully understood in protozoan parasitic diseases, bringing major difficulties to specific therapeutic interventions. The aim of this review is to present the biochemical and molecular mechanisms in kidneys infected with spp., spp., , and spp. We present available mechanisms of an immune response, oxidative stress, apoptosis process, hypoxia, biomarkers of renal injury in the serum or urine, and the histopathological changes of kidneys infected with the selected parasites. Pathomechanisms of spp. and spp. infections have been deeply investigated, while and spp. infections in the kidneys are not well known yet. Deeper knowledge of kidney involvement in leishmaniasis and malaria by presenting their mechanisms provides insight into how to create novel and effective treatments. Additionally, the presented work shows gaps in the pathophysiology of renal toxoplasmosis and acanthamoebiasis, which need further research.
Topics: Animals; Apoptosis; Humans; Kidney; Leishmaniasis; Malaria; Oxidative Stress; Parasitic Diseases; Protozoan Infections; Toxoplasma; Toxoplasmosis; Transforming Growth Factor beta
PubMed: 33921746
DOI: 10.3390/ijms22084209 -
Parasitology Research Sep 2020Haemosporidia infections may cause major damage to avian populations and represent a concern for veterinarians working in zoological parks or wildlife rescue centres....
Haemosporidia infections may cause major damage to avian populations and represent a concern for veterinarians working in zoological parks or wildlife rescue centres. Following the fatal infection of 9 Great grey owls (Strix nebulosa) at Mulhouse zoological park, between summer 2013 and 2015, a prospective epidemiological investigation was performed in captive strigiform birds in France in 2016. The purpose was to evaluate the prevalence of haemosporidian parasites in captive Strigiformes and to estimate the infection dynamics around the nesting period. Blood samples were taken from 122 strigiform birds representing 14 species from 15 French zoological parks. Parasites were detected by direct examination of blood smears and by PCR targeting the mitochondrial cytochrome b gene. Haemosporidian parasites were detected in 59 birds from 11 zoos. Three distinct Haemoproteus mitochondrial cytochrome b sequences (haplotypes A and C for H. syrnii and haplotype B for Haemoproteus sp.) as well as two species of Plasmodium were detected. The overall prevalence of Haemoproteus infection was 12.8%. The percentage of birds infected by Haemoproteus varied according to the period of sampling. Nesting season seemed to be at greater risk with an average prevalence of 53.9% compared with winter season with an average prevalence of 14.8%, related to the abundance of the vectors. The prevalence of Plasmodium infection in Strigiformes did not exceed 8% throughout the year. This study confirmed how significant Haemosporidia infection could be in Strigiformes from zoological parks in France. The nesting season was identified as a period of higher risk of infection and consequently the appropriate period to apply prophylactic measures.
Topics: Animals; Bird Diseases; Cytochromes b; France; Haemosporida; Haplotypes; Phylogeny; Prospective Studies; Protozoan Infections, Animal; Protozoan Proteins; Strigiformes
PubMed: 32683557
DOI: 10.1007/s00436-020-06801-5 -
International Journal For Parasitology Oct 2017Apicomplexan parasites such as Babesia, Theileria, Eimeria, Cryptosporidium and Toxoplasma greatly impact animal health globally, and improved, cost-effective measures... (Review)
Review
Apicomplexan parasites such as Babesia, Theileria, Eimeria, Cryptosporidium and Toxoplasma greatly impact animal health globally, and improved, cost-effective measures to control them are urgently required. These parasites have complex multi-stage life cycles including obligate intracellular stages. Major gaps in our understanding of the biology of these relatively poorly characterised parasites and the diseases they cause severely limit options for designing novel control methods. Here we review potentially important shared aspects of the biology of these parasites, such as cell invasion, host cell modification, and asexual and sexual reproduction, and explore the potential of the application of relatively well-established or newly emerging genetic manipulation methods, such as classical transfection or gene editing, respectively, for closing important gaps in our knowledge of the function of specific genes and proteins, and the biology of these parasites. In addition, genetic manipulation methods impact the development of novel methods of control of the diseases caused by these economically important parasites. Transient and stable transfection methods, in conjunction with whole and deep genome sequencing, were initially instrumental in improving our understanding of the molecular biology of apicomplexan parasites and paved the way for the application of the more recently developed gene editing methods. The increasingly efficient and more recently developed gene editing methods, in particular those based on the CRISPR/Cas9 system and previous conceptually similar techniques, are already contributing to additional gene function discovery using reverse genetics and related approaches. However, gene editing methods are only possible due to the increasing availability of in vitro culture, transfection, and genome sequencing and analysis techniques. We envisage that rapid progress in the development of novel gene editing techniques applied to apicomplexan parasites of veterinary interest will ultimately lead to the development of novel and more efficient methods for disease control.
Topics: Animals; Apicomplexa; CRISPR-Cas Systems; DNA Repair; Deoxyribonucleases; Gene Editing; Gene Knockout Techniques; Genome, Protozoan; Life Cycle Stages; Mutagenesis, Insertional; Protozoan Infections, Animal; Protozoan Vaccines; Transfection; Virulence Factors
PubMed: 28893636
DOI: 10.1016/j.ijpara.2017.08.002 -
Current Opinion in Neurology Jun 2021Malaria, Chagas Disease and Human African Trypanosomiasis are vector-borne protozoan illnesses, frequently associated with neurological manifestations. Intriguing but... (Review)
Review
PURPOSE OF REVIEW
Malaria, Chagas Disease and Human African Trypanosomiasis are vector-borne protozoan illnesses, frequently associated with neurological manifestations. Intriguing but ignored, limited mainly to resource-limited, tropical settings, these disorders are now coming to light because of globalisation and improved diagnosis and treatment. Enhanced understanding of these illnesses has prompted this review.
RECENT FINDINGS
Methods of diagnosis have currently transitioned from blood smear examinations to immunological assays and molecular methods. Tools to assess neurological involvement, such as magnetic resonance imaging, are now increasingly available in regions and countries with high infection loads. Sleep and other electrophysiological technologies (electroencephalography, actigraphy) are also promising diagnostic tools but requiring field-validation. Access to treatments was formerly limited, even as limitations of agents used in the treatment are increasingly recognised. Newer agents are now being developed and trialled, encouraged by improved understanding of the disorders' molecular underpinnings.
SUMMARY
Prompt diagnosis and treatment are crucial in ensuring cure from the infections. Attention should also be due to the development of globally applicable treatment guidelines, the burden of neurological sequelae and elimination of the zoonoses from currently endemic regions.
Topics: Animals; Chagas Disease; Humans; Malaria, Cerebral; Trypanosomiasis, African
PubMed: 33709976
DOI: 10.1097/WCO.0000000000000919