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Clinical Microbiology and Infection :... Feb 2008Mycoplasma is a well-recognised pathogen that colonises mucosal surfaces of humans and animals. Mycoplasma pneumoniae infects the upper and lower respiratory tracts of... (Review)
Review
Mycoplasma is a well-recognised pathogen that colonises mucosal surfaces of humans and animals. Mycoplasma pneumoniae infects the upper and lower respiratory tracts of children and adults, leading to a wide range of respiratory and non-respiratory clinical conditions. M. pneumoniae infection is frequently considered in the differential diagnosis of patients with respiratory illnesses, and is commonly managed empirically with macrolides and fluoroquinolones. This contrasts with patients who present with non-respiratory symptoms in the context of a recent or current unrecognised M. pneumoniae infection, for whom this pathogen is rarely considered in the initial differential diagnosis. This review considers the microbiological, epidemiological, pathogenic and clinical features of this frequent pathogen that need to be considered in the differential diagnosis of respiratory and non-respiratory infections.
Topics: Anti-Bacterial Agents; Communicable Diseases, Emerging; Diagnosis, Differential; Humans; Mycoplasma Infections; Mycoplasma pneumoniae; Pneumonia, Mycoplasma
PubMed: 17949442
DOI: 10.1111/j.1469-0691.2007.01834.x -
Bailliere's Clinical Haematology Mar 1995Pathogenicity is a complex process with stringent requirements of both the host cell and the infecting virion. Among these requirements are a port of entry into host... (Review)
Review
Pathogenicity is a complex process with stringent requirements of both the host cell and the infecting virion. Among these requirements are a port of entry into host cells, a means of replication for the virus, and a means by which infection damages host cells. Damage to the host can result from multiple mechanisms including transformation, suppression of cellular metabolism, apoptosis, autoimmune responses directed against infected or uninfected tissues, or by molecular mimicry. In the attempt to identify new associations between viral infection and disease, investigators should be mindful that variable host factors as well as viral infection may be required for pathogenesis. Efforts to associate specific viral infections with specific diseases may be obscured by final common pathways through which multiple agents damage host cells in similar ways.
Topics: Animals; Antibodies, Viral; Apoptosis; Autoimmune Diseases; Cell Transformation, Viral; Cytopathogenic Effect, Viral; Humans; Immunity, Cellular; Mice; Mice, Inbred BALB C; Molecular Mimicry; Virulence; Virus Diseases; Virus Physiological Phenomena; Virus Replication; Viruses
PubMed: 7663043
DOI: 10.1016/s0950-3536(05)80230-6 -
Parasite (Paris, France) Sep 2008Airborne transmission of Pneumocystis sp. from host to host has been demonstrated in rodent models and several observations suggest that interindividual transmission... (Review)
Review
Airborne transmission of Pneumocystis sp. from host to host has been demonstrated in rodent models and several observations suggest that interindividual transmission occurs in humans. Moreover, it is accepted that the Pneumocystis organisms infecting each mammalian species are host specific and that the hypothesis of an animal reservoir for Pneumocystis jirovecii (P. jirovecii), the human-specific Pneumocystis species, can be excluded. An exosaprophytic form of the fungus cannot be strictly ruled out. However, these data point toward the potential for the specific host to serve as its own reservoir and for Pneumocystis infection in humans as an anthroponosis with humans as a reservoir for P. jirovecii. This review highlights the main data on host-to-host transmission of Pneumocystis in rodent models and in humans by the airborne route and provides a rationale for considering the occurrence of nosocomial infections and measures for their prevention
Topics: Air Microbiology; Animals; Cross Infection; Disease Reservoirs; Disease Transmission, Infectious; Host-Pathogen Interactions; Humans; Pneumocystis Infections; Pneumocystis carinii; Pneumonia, Pneumocystis; Species Specificity
PubMed: 18814707
DOI: 10.1051/parasite/2008153359 -
Clinical Infectious Diseases : An... Jul 2012The impact of hepatitis C virus (HCV) infection on health and medical care in the United States is a major problem for infectious disease physicians. Although the... (Review)
Review
The impact of hepatitis C virus (HCV) infection on health and medical care in the United States is a major problem for infectious disease physicians. Although the incidence of HCV infection has declined markedly in the past 2 decades, chronic infection in 3 million or more residents now accounts for more disease and death in the United States than does human immunodeficiency virus (HIV)/AIDS. Current trends in the epidemiology of HCV infection include an apparent increase in young, often suburban heroin injection drug users who initiate use with oral prescription opioid drugs; infections in nonhospital healthcare (clinic) settings; and sexual transmission among HIV-infected persons. Infectious disease physicians will increasingly have the responsibility of diagnosing and treating HCV patients. An understanding of how these patients were infected is important for determining whom to screen and treat.
Topics: Blood; Body Piercing; Cross Infection; HIV; HIV Infections; Hepacivirus; Hepatitis C; Humans; Incidence; Risk Factors; Substance Abuse, Intravenous; United States
PubMed: 22715211
DOI: 10.1093/cid/cis393 -
Frontiers in Cellular and Infection... 2022Emerging infectious disease has become the center of attention since the outbreak of COVID-19. For the coronavirus, bats are suspected to be the origin of the pandemic.... (Review)
Review
Emerging infectious disease has become the center of attention since the outbreak of COVID-19. For the coronavirus, bats are suspected to be the origin of the pandemic. Consequently, the spotlight has fallen on zoonotic diseases, and the focus now expands to organisms other than viruses. Microsporidia is a single-cell organism that can infect a wide range of hosts such as insects, mammals, and humans. Its pathogenicity differs among species, and host immunological status plays an important role in infectivity and disease severity. Disseminated disease from microsporidiosis can be fatal, especially among patients with a defective immune system. Recently, there were two , a microsporidia species which can survive in insects, case reports in Thailand, one patient had disseminated microsporidiosis. This review gathered data of disseminated microsporidiosis and infections in humans covering the biological and clinical aspects. There was a total of 22 cases of disseminated microsporidiosis reports worldwide. Ten microsporidia species were identified. Maximum likelihood tree results showed some possible correlations with zoonotic transmissions. For hominis, there are currently eight case reports in humans, seven of which had Human Immunodeficiency Virus (HIV) infection. It is observed that risks are higher for the immunocompromised to acquire such infections, however, future studies should look into the entire life cycle, to identify the route of transmission and establish preventive measures, especially among the high-risk groups.
Topics: Animals; COVID-19; Humans; Immunocompromised Host; Mammals; Microsporidia; Microsporidiosis; Zoonoses
PubMed: 35782144
DOI: 10.3389/fcimb.2022.924007 -
Clinical Microbiology Reviews Jan 2010In global terms, respiratory viral infection is a major cause of morbidity and mortality. Infancy, in particular, is a time of increased disease susceptibility and... (Review)
Review
In global terms, respiratory viral infection is a major cause of morbidity and mortality. Infancy, in particular, is a time of increased disease susceptibility and severity. Early-life viral infection causes acute illness and can be associated with the development of wheezing and asthma in later life. The most commonly detected viruses are respiratory syncytial virus (RSV), rhinovirus (RV), and influenza virus. In this review we explore the complete picture from epidemiology and virology to clinical impact and immunology. Three striking aspects emerge. The first is the degree of similarity: although the infecting viruses are all different, the clinical outcome, viral evasion strategies, immune response, and long-term sequelae share many common features. The second is the interplay between the infant immune system and viral infection: the immaturity of the infant immune system alters the outcome of viral infection, but at the same time, viral infection shapes the development of the infant immune system and its future responses. Finally, both the virus and the immune response contribute to damage to the lungs and subsequent disease, and therefore, any prevention or treatment needs to address both of these factors.
Topics: Child, Preschool; Humans; Infant; Infant, Newborn; Respiratory Tract Infections; Virus Diseases; Viruses
PubMed: 20065326
DOI: 10.1128/CMR.00032-09 -
Current Opinion in Virology Aug 2019Enteric viruses infect the mammalian gastrointestinal tract which is home to a diverse community of intestinal bacteria. Accumulating evidence suggests that certain... (Review)
Review
Enteric viruses infect the mammalian gastrointestinal tract which is home to a diverse community of intestinal bacteria. Accumulating evidence suggests that certain enteric viruses utilize these bacteria to promote infection. While this is not surprising considering their proximity, multiple viruses from different viral families have been shown to bind directly to bacteria or bacterial components to aid in viral replication, pathogenesis, and transmission. These data suggest that the concept of a single virus infecting a single cell, independent of the environment, needs to be reevaluated. In this review, I will discuss the current knowledge of enteric virus-bacterial interactions and discuss the implications for viral pathogenesis and transmission.
Topics: Animals; Gastrointestinal Tract; Host Microbial Interactions; Humans; Immune Evasion; Microbial Interactions; Microbiota; Picornaviridae; Picornaviridae Infections; Reoviridae; Reoviridae Infections; Retroviridae; Retroviridae Infections; Virus Diseases; Virus Replication; Viruses
PubMed: 31284078
DOI: 10.1016/j.coviro.2019.06.002 -
Mathematical Biosciences and...In this paper, we consider a compartmental SIRS epidemic model with asymptomatic infection and seasonal succession, which is a periodic discontinuous differential...
In this paper, we consider a compartmental SIRS epidemic model with asymptomatic infection and seasonal succession, which is a periodic discontinuous differential system. The basic reproduction number R0 is defined and evaluated directly for this model, and uniform persistence of the disease and threshold dynamics are obtained. Specially, global dynamics of the model without seasonal force are studied. It is shown that the model has only a disease-free equilibrium which is globally stable if R0 ≤ 1, and as R0 > 1 the disease-free equilibrium is unstable and there is an endemic equilibrium, which is globally stable if the recovering rates of asymptomatic infectives and symptomatic infectives are close. These theoretical results provide an intuitive basis for understanding that the asymptomatically infective individuals and the seasonal disease transmission promote the evolution of the epidemic, which allow us to predict the outcomes of control strategies during the course of the epidemic.
Topics: Algorithms; Asymptomatic Infections; Basic Reproduction Number; Epidemics; Humans; Infections; Infectious Disease Medicine; Influenza, Human; Models, Theoretical; Seasons
PubMed: 29161868
DOI: 10.3934/mbe.2017073 -
Frontiers in Cellular and Infection... 2012Glycan based interactions between host and pathogen are critical in many bacterial and viral diseases. Glycan interactions range from initial receptor based adherence to... (Review)
Review
Glycan based interactions between host and pathogen are critical in many bacterial and viral diseases. Glycan interactions range from initial receptor based adherence to protecting the infective agent from the host's immune response through molecular mimicry. Campylobacter jejuni is an ideal model for studying the role of glycans in host-pathogen interactions, as well as the role of bacterial surface glycoconjugates in infection. Using glycan array analysis, C. jejuni has been shown to interact with a wide range of host glycoconjugates. Mannose and sialic acid residues appear to play a role in initial interactions between host and pathogen following environmental exposure, whereas fucose and galactose based interactions are likely to be required for prolonged colonization. Other studies have highlighted potential decoy receptor type interactions between host's intestinal mucins and C. jejuni, demonstrating the importance of host glycoproteins as defense against C. jejuni infection as well as the role for glycoconjugates found in human breast milk in protection of breast feeding infants from infection with C. jejuni. C. jejuni can produce N- and O-linked glycoproteins, capsular polysaccharide (CPS) and/or lipooligosaccharide (LOS) which results in C. jejuni presenting its own diverse sugar coated displays on the cell surface. Bacterial glycans play an important and versatile role in infection and disease. Of these, the best understood is the molecular mimicry of human gangliosides presented by C. jejuni's LOS and its link to the onset of autoimmune neuropathies such as the Guillain Barrè syndrome (GBS). However, the role of glycoconjugates presented by C. jejuni extends beyond expression of sialylated ganglioside structures involved in initiation of GBS. Expression of surface glycans by C. jejuni may also relate to the ability of this organism to interact with the glycoproteins for initial host-pathogen interactions and continued infectivity.
Topics: Autoimmune Diseases; Bacterial Adhesion; Campylobacter Infections; Campylobacter jejuni; Glycoconjugates; Host-Pathogen Interactions; Humans; Virulence Factors
PubMed: 22919601
DOI: 10.3389/fcimb.2012.00009 -
Cold Spring Harbor Perspectives in... Nov 2014Few among the millions of fungal species fulfill four basic conditions necessary to infect humans: high temperature tolerance, ability to invade the human host, lysis... (Review)
Review
Few among the millions of fungal species fulfill four basic conditions necessary to infect humans: high temperature tolerance, ability to invade the human host, lysis and absorption of human tissue, and resistance to the human immune system. In previously healthy individuals, invasive fungal disease is rare because animals' sophisticated immune systems evolved in constant response to fungal challenges. In contrast, fungal diseases occur frequently in immunocompromised patients. Paradoxically, successes of modern medicine have put increasing numbers of patients at risk for invasive fungal infections. Uncontrolled HIV infection additionally makes millions vulnerable to lethal fungal diseases. A concerted scientific and social effort is needed to meet these challenges.
Topics: Biological Evolution; Fungi; Humans; Immunity, Innate; Immunocompromised Host; Mycoses; Opportunistic Infections; Virulence
PubMed: 25367975
DOI: 10.1101/cshperspect.a019273