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Journal of Microbiology, Immunology,... Feb 2021Since the outbreak of coronavirus disease 2019 (COVID-19) in late December 2019, it has brought significant harm and challenges to over 200 countries and regions around...
Since the outbreak of coronavirus disease 2019 (COVID-19) in late December 2019, it has brought significant harm and challenges to over 200 countries and regions around the world. However, there is increasing evidence that many patients with COVID-19 are asymptomatic or have only mild symptoms, but they are able to transmit the virus to others. There are difficulties in screening for asymptomatic infections, which makes it more difficult for national prevention and control of this epidemic. This article reviews the characteristics, treatment, and outcomes of asymptomatic infections with COVID-19, hoping it would be helpful for early prevention and control of this severe public health threat worldwide.
Topics: Asymptomatic Infections; COVID-19; COVID-19 Nucleic Acid Testing; Disease Outbreaks; Humans; SARS-CoV-2; Treatment Outcome
PubMed: 32425996
DOI: 10.1016/j.jmii.2020.05.001 -
The Lancet. Infectious Diseases Jan 2020Creutzfeldt-Jakob disease (CJD) is a fatal disease presenting with rapidly progressive dementia, and most patients die within a year of clinical onset. CJD poses a...
Creutzfeldt-Jakob disease (CJD) is a fatal disease presenting with rapidly progressive dementia, and most patients die within a year of clinical onset. CJD poses a potential risk of iatrogenic transmission, as it can incubate asymptomatically in humans for decades before becoming clinically apparent. In this Review, we sought evidence to understand the current iatrogenic risk of CJD to public health by examining global evidence on all forms of CJD, including clinical incidence and prevalence of subclinical disease. We found that although CJD, particularly iatrogenic CJD, is rare, the incidence of sporadic CJD is increasing. Incubation periods as long as 40 years have been observed, and all genotypes have now been shown to be susceptible to CJD. Clinicians and surveillance programmes should maintain awareness of CJD to mitigate future incidences of its transmission. Awareness is particularly relevant for sporadic CJD, which occurs in older people in whom clinical presentation could resemble rapidly developing dementia.
Topics: Adult; Aged; Aged, 80 and over; Creutzfeldt-Jakob Syndrome; Female; Humans; Iatrogenic Disease; Incidence; Infectious Disease Incubation Period; Male; Middle Aged; Prevalence; Risk Assessment; Young Adult
PubMed: 31876504
DOI: 10.1016/S1473-3099(19)30615-2 -
Dermatologic Clinics Oct 2021Children are a unique subset of patients in relation to the COVID-19 pandemic, often presenting asymptomatically, mildly, or atypically. Manifestations of the skin may... (Review)
Review
Children are a unique subset of patients in relation to the COVID-19 pandemic, often presenting asymptomatically, mildly, or atypically. Manifestations of the skin may be a primary (or the only) presenting sign. Recognizing cutaneous manifestations of COVID-19 in the pediatric population is important to guiding precautions, testing, and management for patients and close contacts. Whereas some dermatologic signs in children overlap with those in adults, other skin findings are reported with higher frequency in children and may be clues to multisystemic sequelae. This article describes presentation, pathophysiologic theories, and management strategies for cutaneous manifestations of COVID-19 in children.
Topics: COVID-19; COVID-19 Testing; Child; Humans; Skin Diseases, Viral; Systemic Inflammatory Response Syndrome
PubMed: 34556241
DOI: 10.1016/j.det.2021.05.012 -
Cell Host & Microbe Apr 2023Candida auris and Candida albicans can result in invasive fungal diseases. And yet, these species can stably and asymptomatically colonize human skin and... (Review)
Review
Candida auris and Candida albicans can result in invasive fungal diseases. And yet, these species can stably and asymptomatically colonize human skin and gastrointestinal tracts. To consider these disparate microbial lifestyles, we first review factors shown to influence the underlying microbiome. Structured by the damage response framework, we then consider the molecular mechanisms deployed by C. albicans to switch between commensal and pathogenic lifestyles. Next, we explore this framework with C. auris to highlight how host physiology, immunity, and/or antibiotic receipt are associated with progression from colonization to infection. While treatment with antibiotics increases the risk that an individual will succumb to invasive candidiasis, the underlying mechanisms remain unclear. Here, we describe several hypotheses that may explain this phenomenon. We conclude by highlighting future directions integrating genomics with immunology to advance our understanding of invasive candidiasis and human fungal disease.
Topics: Humans; Mycobiome; Symbiosis; Host-Pathogen Interactions; Candida albicans; Candidiasis, Invasive
PubMed: 37054674
DOI: 10.1016/j.chom.2023.02.010 -
Mathematical Biosciences and... Nov 2020Asymptomatic transmission of infectious diseases has been recognized recently in several epidemics or pandemics. There is a great need to incorporate asymptomatic...
Asymptomatic transmission of infectious diseases has been recognized recently in several epidemics or pandemics. There is a great need to incorporate asymptomatic transmissions into traditional modeling of infectious diseases and to study how asymptomatic transmissions shift epidemic dynamics. In this work, we propose a compartmental model with asymptomatic transmissions for waterborne infectious diseases. We conduct a detailed analysis and numerical study with shigellosis data. Two parameters, the proportion $p$ of asymptomatic infected individuals and the proportion $k$ of asymptomatic infectious individuals who can asymptomatically transmit diseases, play major rules in the epidemic dynamics. The basic reproduction number $\mathscr{R}_{0}$ is a decreasing function of parameter $p$ when parameter $k$ is smaller than a critical value while $\mathscr{R}_{0}$ is an increasing function of $p$ when $k$ is greater than the critical value. $\mathscr{R}_{0}$ is an increasing function of $k$ for any value of $p$. When $\mathscr{R}_{0}$ passes through 1 as $p$ or $k$ varies, the dynamics of epidemics is shifted. If asymptomatic transmissions are not counted, $\mathscr{R}_{0}$ will be underestimated while the final size may be overestimated or underestimated. Our study provides a theoretical example for investigating other asymptomatic transmissions and useful information for public health measurements in waterborne infectious diseases.
Topics: Asymptomatic Infections; Basic Reproduction Number; Communicable Diseases; Epidemics; Humans; Pandemics
PubMed: 33525082
DOI: 10.3934/mbe.2021005 -
PLoS Pathogens May 2023Streptococcus pneumoniae is an opportunistic pathogen that colonizes the upper respiratory tract asymptomatically and, upon invasion, can lead to severe diseases...
Streptococcus pneumoniae is an opportunistic pathogen that colonizes the upper respiratory tract asymptomatically and, upon invasion, can lead to severe diseases including otitis media, sinusitis, meningitis, bacteremia, and pneumonia. One of the first lines of defense against pneumococcal invasive disease is inflammation, including the recruitment of neutrophils to the site of infection. The invasive pneumococcus can be cleared through the action of serine proteases generated by neutrophils. It is less clear how serine proteases impact non-invasive pneumococcal colonization, which is the key first step to invasion and transmission. One significant aspect of pneumococcal biology and adaptation in the respiratory tract is its natural competence, which is triggered by a small peptide CSP. In this study, we investigate if serine proteases are capable of degrading CSP and the impact this has on pneumococcal competence. We found that CSP has several potential sites for trypsin-like serine protease degradation and that there were preferential cleavage sites recognized by the proteases. Digestion of CSP with two different trypsin-like serine proteases dramatically reduced competence in a dose-dependent manner. Incubation of CSP with mouse lung homogenate also reduced recombination frequency of the pneumococcus. These ex vivo experiments suggested that serine proteases in the lower respiratory tract reduce pneumococcal competence. This was subsequently confirmed measuring in vivo recombination frequencies after induction of protease production via poly (I:C) stimulation and via co-infection with influenza A virus, which dramatically lowered recombination events. These data shed light on a new mechanism by which the host can modulate pneumococcal behavior and genetic exchange via direct degradation of the competence signaling peptide.
Topics: Animals; Mice; Streptococcus pneumoniae; Pneumococcal Infections; Inflammation; Serine Proteases; Peptides
PubMed: 37256908
DOI: 10.1371/journal.ppat.1011421 -
Reumatologia Clinica May 2021Uric acid has been related to a tendency to precipitate to form crystals, presenting asymptomatically, until the formation of arthritis, tophi or renal lithiasis....
BACKGROUND
Uric acid has been related to a tendency to precipitate to form crystals, presenting asymptomatically, until the formation of arthritis, tophi or renal lithiasis. Previously, the presence of asymptomatic hyperuricaemia has been associated with the presence of cardiovascular disease.
OBJECTIVES
To determine the association of complex coronary artery disease in patients with asymptomatic hyperuricaemia.
MATERIAL AND METHODS
An observational retrospective, transversal, unicentric study was conducted in a tertiary hospital in Mexico, in the period from June 2017 to March 2019. All patients admitted for coronary angiography were included; patients with gout, use of diuretics and chronic kidney disease were excluded.
RESULTS
During the study period, a total of 300 patients were collected, of which 40% presented hyperuricaemia. The patients with hyperuricaemia were older (59 vs. 63, P = .002). The group of patients with asymptomatic hyperuricaemia had a higher proportion of complex coronary lesions (64 vs. 35%, P ≤ .0001) as well as a higher SYNTAX I score (27 vs. 17, P ≤ .001). There was a higher probability of presenting complex coronary lesions in this group of patients (OR 3.4, P ≤ .0001). In addition, in the group division of uric acid levels, it was related to the presence of complex coronary lesions (Q1 = .5, P = .06), (Q2 = 2, P = .01) and (Q3 = 3, P ≤ .0001).
CONCLUSION
Asymptomatic hyperuricaemia has a higher prevalence and association of presenting complex coronary lesions.
PubMed: 31707094
DOI: 10.1016/j.reuma.2019.08.003 -
International Journal of Infectious... Nov 2020While successful containment measures of COVID-19 in China and many European countries have led to flattened curves, case numbers are rising dramatically in other... (Review)
Review
While successful containment measures of COVID-19 in China and many European countries have led to flattened curves, case numbers are rising dramatically in other countries, with the emergence of a second wave expected. Asymptomatic individuals carrying SARS-CoV-2 are hidden drivers of the pandemic, and infectivity studies confirm the existence of transmission by asymptomatic individuals. The data addressed here show that characteristics of asymptomatic and presymptomatic infection are not identical. Younger age correlates strongly with asymptomatic and mild infections and children as hidden drivers. The estimated proportion of asymptomatic infections ranges from 18% to 81%. The current perception of asymptomatic infections does not provide clear guidance for public-health measures. Asymptomatic infections will be a key contributor in the spread of COVID-19. Asymptomatic cases should be reported in official COVID-19 statistics.
Topics: Adult; Asymptomatic Infections; Betacoronavirus; COVID-19; Child; Coronavirus Infections; Humans; Immunity, Herd; Middle Aged; Pandemics; Pneumonia, Viral; Public Health; SARS-CoV-2
PubMed: 32891737
DOI: 10.1016/j.ijid.2020.08.076