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Current Opinion in Infectious Diseases Aug 2013The aim is to discuss the epidemiology of infections that arise from contaminated water in healthcare settings, including Legionnaires' disease, other Gram-negative... (Review)
Review
PURPOSE OF REVIEW
The aim is to discuss the epidemiology of infections that arise from contaminated water in healthcare settings, including Legionnaires' disease, other Gram-negative pathogens, nontuberculous mycobacteria, and fungi.
RECENT FINDINGS
Legionella can colonize a hospital water system and infect patients despite use of preventive disinfectants. Evidence-based measures are available for secondary prevention. Vulnerable patients can develop healthcare-associated infections with waterborne organisms that are transmitted by colonization of plumbing systems, including sinks and their fixtures. Room humidifiers and decorative fountains have been implicated in serious outbreaks, and pose unwarranted risks in healthcare settings.
SUMMARY
Design of hospital plumbing must be purposeful and thoughtful to avoid the features that foster growth and dissemination of Legionella and other pathogens. Exposure of patients who have central venous catheters and other invasive devices to tap water poses a risk for infection with waterborne pathogens. Healthcare facilities must conduct aggressive clinical surveillance for Legionnaires' disease and other waterborne infections in order to detect and remediate an outbreak promptly. Hand hygiene is the most important measure to prevent transmission of other Gram-negative waterborne pathogens in the healthcare setting.
Topics: Bacterial Infections; Disease Reservoirs; Drinking Water; Hospitals; Humans; Legionnaires' Disease; Mycoses; Protozoan Infections; Water Supply
PubMed: 23806897
DOI: 10.1097/QCO.0b013e3283630adf -
Cellular and Molecular Life Sciences :... Apr 2014Numerous disease-causing parasites must invade host cells in order to prosper. Collectively, such pathogens are responsible for a staggering amount of human sickness and... (Review)
Review
Numerous disease-causing parasites must invade host cells in order to prosper. Collectively, such pathogens are responsible for a staggering amount of human sickness and death throughout the world. Leishmaniasis, Chagas disease, toxoplasmosis, and malaria are neglected diseases and therefore are linked to socio-economical and geographical factors, affecting well-over half the world's population. Such obligate intracellular parasites have co-evolved with humans to establish a complexity of specific molecular parasite-host cell interactions, forming the basis of the parasite's cellular tropism. They make use of such interactions to invade host cells as a means to migrate through various tissues, to evade the host immune system, and to undergo intracellular replication. These cellular migration and invasion events are absolutely essential for the completion of the lifecycles of these parasites and lead to their for disease pathogenesis. This review is an overview of the molecular mechanisms of protozoan parasite invasion of host cells and discussion of therapeutic strategies, which could be developed by targeting these invasion pathways. Specifically, we focus on four species of protozoan parasites Leishmania, Trypanosoma cruzi, Plasmodium, and Toxoplasma, which are responsible for significant morbidity and mortality.
Topics: Animals; Chagas Disease; Host-Parasite Interactions; Humans; Leishmania; Leishmaniasis; Malaria; Parasites; Phagocytes; Plasmodium; Protozoan Infections; Toxoplasma; Trypanosoma cruzi
PubMed: 24221133
DOI: 10.1007/s00018-013-1491-1 -
European Journal of Immunology Nov 2010Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that share a common property of suppressing immune responses. Several... (Review)
Review
Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that share a common property of suppressing immune responses. Several helminth and protozoan parasite species have developed efficient strategies to increase the rate of medullary or extramedullary myelopoiesis and to induce the expansion and accumulation of immature myeloid cells such as MDSC. In this review, we examine current knowledge on the factors mediating enhanced myelopoiesis and MDSC induction and recruitment during parasitic infections and how the MDSC phenotype and mechanism of immune modulation and suppression depends on the factors they encounter within the host. Finally, we place MDSC expansion in the context of the critical balance between parasite elimination and pathogenicity to the host and suggest attractive avenues for future research.
Topics: Animals; Helminthiasis; Hematopoiesis, Extramedullary; Host-Parasite Interactions; Humans; Myeloid Cells; Myelopoiesis; Protozoan Infections
PubMed: 21061431
DOI: 10.1002/eji.201040911 -
Acta Tropica Jul 2023Annexins (ANXs) exert different functions in cell biological and pathological processes and are thus known as double or multi-faceted proteins. These sophisticated... (Review)
Review
Annexins (ANXs) exert different functions in cell biological and pathological processes and are thus known as double or multi-faceted proteins. These sophisticated proteins might express on both parasite structure and secretion and in parasite-infected host cells. In addition to the characterization of these pivotal proteins, describing their mechanism of action can be also fruitful in recognizing their roles in the pathogenesis of parasitic infections. Accordingly, this study presents the most prominent ANXs thus far identified and their relevant functions in parasites and infected host cells during pathogenesis, especially in the most important intracellular protozoan parasitic infections including leishmaniasis, toxoplasmosis, malaria and trypanosomiasis. The data provided in this study demonstrate that the helminth parasites most probably express and secret ANXs to develop pathogenesis while the modulation of the host-ANXs could be employed as a crucial strategy by intracellular protozoan parasites. Moreover, such data highlight that the use of analogs of both parasite and host ANX peptides (which mimic or regulate ANXs physiological functions through various strategies) might suggest novel therapeutic insights into the treatment of parasitic infections. Furthermore, due to the prominent immunoregulatory activities of ANXs during most parasitic infections and the expression levels of these proteins in some parasitic infected tissues, such multifunctional proteins might be also potentially relevant as vaccine and diagnostic biomarkers. We also suggest some prospects and insights that could be useful and applicable to form the basis of future experimental studies.
Topics: Animals; Humans; Annexins; Parasitic Diseases; Protozoan Infections; Malaria; Leishmaniasis; Parasites
PubMed: 37172709
DOI: 10.1016/j.actatropica.2023.106942 -
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 Environmental... May 2013Water-related parasitic diseases are directly dependent on water bodies for their spread or as a habitat for indispensable intermediate or final hosts. Along with... (Review)
Review
Water-related parasitic diseases are directly dependent on water bodies for their spread or as a habitat for indispensable intermediate or final hosts. Along with socioeconomic development and improvement of sanitation, overall prevalence is declining in the China. However, the heterogeneity in economic development and the inequity of access to public services result in considerable burden due to parasitic diseases in certain areas and populations across the country. In this review, we demonstrated three aspects of ten major water-related parasitic diseases, i.e., the biology and pathogenicity, epidemiology and recent advances in research in China. General measures for diseases control and special control strategies are summarized.
Topics: Amoebida; Animals; China; Eimeriida; Eukaryota; Fresh Water; Giardia lamblia; Helminthiasis; Humans; Protozoan Infections; Trematoda
PubMed: 23685826
DOI: 10.3390/ijerph10051977 -
Science (New York, N.Y.) Dec 2009Few infectious diseases are entirely human-specific: Most human pathogens also circulate in animals or else originated in nonhuman hosts. Influenza, plague, and... (Review)
Review
Few infectious diseases are entirely human-specific: Most human pathogens also circulate in animals or else originated in nonhuman hosts. Influenza, plague, and trypanosomiasis are classic examples of zoonotic infections that transmit from animals to humans. The multihost ecology of zoonoses leads to complex dynamics, and analytical tools, such as mathematical modeling, are vital to the development of effective control policies and research agendas. Much attention has focused on modeling pathogens with simpler life cycles and immediate global urgency, such as influenza and severe acute respiratory syndrome. Meanwhile, vector-transmitted, chronic, and protozoan infections have been neglected, as have crucial processes such as cross-species transmission. Progress in understanding and combating zoonoses requires a new generation of models that addresses a broader set of pathogen life histories and integrates across host species and scientific disciplines.
Topics: Animals; Bacterial Infections; Disease Outbreaks; Host-Pathogen Interactions; Humans; Models, Statistical; Population Dynamics; Protozoan Infections; Protozoan Infections, Animal; Virus Diseases; Zoonoses
PubMed: 19965751
DOI: 10.1126/science.1177345 -
Trends in Parasitology Sep 2012Protozoan parasites cause severe morbidity and mortality in humans worldwide, especially in developing countries where access to chemotherapeutic agents is limited.... (Review)
Review
Protozoan parasites cause severe morbidity and mortality in humans worldwide, especially in developing countries where access to chemotherapeutic agents is limited. Although parasites initially evoke a robust immune response, subsequent immunity fails to clear infection, ultimately leading to the chronic stage. This enigmatic situation was initially addressed in chronic viral models, where T cells lose their function, a phenomenon referred to as 'exhaustion'. However, recent studies demonstrate that this paradigm can be extended to protozoan diseases as well, although with notable differences. These studies have revealed that T cell responses generated against Toxoplasma gondii, Plasmodium sp., and Leishmania sp. can become dysfunctional. This review discusses T cell exhaustion in parasitic infection, mechanisms of development, and a possible role in disease outcome.
Topics: Host-Parasite Interactions; Humans; Protozoan Infections; T-Lymphocytes
PubMed: 22832368
DOI: 10.1016/j.pt.2012.07.001 -
Clinical Microbiology Reviews Jul 1995Human protozoal infections are ubiquitous and occur worldwide. In many cases, antiprotozoal agents currently in use predate the modern antibiotic era. Despite the... (Review)
Review
Human protozoal infections are ubiquitous and occur worldwide. In many cases, antiprotozoal agents currently in use predate the modern antibiotic era. Despite the relative lag in development of new antiprotozoal agents, the 1990s have witnessed an increasing level of interest in these infections, inspired by international travel and immigration, a growing awareness of antiprotozoal drug resistance, and the significance of acute and recrudescent protozoal infections in immunosuppressed hosts. This review summarizes for nonclinician readers the past, present, and future therapies for common human protozoal infections, as well as pharmacologic mechanisms of action and resistance and common toxicities associated with these agents.
Topics: Antiprotozoal Agents; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Intestinal Diseases, Parasitic; Parasitemia; Protozoan Infections
PubMed: 7553575
DOI: 10.1128/CMR.8.3.427 -
Seminars in Neurology Sep 2005Parasitic infection of the nervous system can produce a variety of symptoms and signs. Because symptoms of infection are often mild or nonspecific, diagnosis can be... (Review)
Review
Parasitic infection of the nervous system can produce a variety of symptoms and signs. Because symptoms of infection are often mild or nonspecific, diagnosis can be difficult. Familiarity with basic epidemiological characteristics and distinguishing radiographic findings can increase the likelihood of detection and proper treatment of parasitic infection of the nervous system. This article discusses the clinical presentation, diagnosis, and treatment for some of the more common infections of the nervous system caused by cestodes, trematodes and protozoans: Echinococcus spp., Spirometra spp. (sparganosis), Paragonimus spp., Schistosoma spp., Trypanosoma spp., Naegleria fowlerii, Acanthamoeba histolytica, and Balamuthia mandrillaris.
Topics: Animals; Cestode Infections; Humans; Nervous System Diseases; Protozoan Infections; Trematode Infections
PubMed: 16170739
DOI: 10.1055/s-2005-917663