Infectivity of asymptomatic versus symptomatic COVID-19.
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ABSTRACT:
SUBMITTER: Sayampanathan AA
PROVIDER: S-EPMC7836843 | biostudies-literature |
REPOSITORIES: biostudies-literature
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2023-10-09 | GSE218908 | GEO
Project description:COVID-19 pandemic exerts a health care emergency around the world. The illness severity is heterogeneous. It is mostly unknown why some individuals who are positive for SARS-CoV-2 antibodies stay asymptomatic while others show moderate to severe disease symptoms. Reliable biomarkers for early detection of the disease are urgently needed to attenuate the virus's spread and help make early treatment decisions. Bioactive sphingolipids play a crucial role in the regulation of viral infections and pro-inflammatory responses involved in the severity of COVID-19. However, any roles of sphingolipids in COVID-19 development or detection remain unknown. In this study, lipidomics measurement of serum sphingolipids demonstrated that reduced sphingosine levels are highly associated with the development of symptomatic COVID-19 in the majority (99.24%) SARS-CoV-2-infected patients compared to asymptomatic counterparts. The majority of asymptomatic individuals (73%) exhibited increased acid ceramidase (AC) in their serum, measured by Western blotting, consistent with elevated sphingosine levels compared to SARS-CoV-2 antibody negative controls. AC protein was also reduced in almost all of the symptomatic patients' serum, linked to reduced sphingosine levels, measured in longitudinal acute or convalescent COVID-19 samples. Thus, reduced sphingosine levels provide a sensitive and selective serologic biomarker for the early identification of asymptomatic versus symptomatic COVID-19 patients.
| S-EPMC8270895 | biostudies-literature
Project description:ObjectivesDetailed knowledge on the prevalence of asymptomatic cases of coronavirus disease 2019 (COVID-19) and the clinical characteristics of mild COVID-19 is essential for effective control of the COVID-19 pandemic. We determined the prevalence of asymptomatic cases of COVID-19 and characterized the symptoms of patients with mild COVID-19.MethodsStudy participants were recruited from a community facility designated for the isolation of patients without moderate-to-severe symptoms of COVID-19 in South Korea. The prevalence of asymptomatic patients at admission and the detailed symptoms of mild COVID-19 were evaluated through a questionnaire-based survey. Diagnosis of COVID-19 was confirmed by real-time RT-PCR.ResultsOf the 213 individuals with COVID-19, 41 (19.2%) were asymptomatic until admission. Among the remaining patients with mild COVID-19, the most common symptom was cough (40.1%; 69/172), followed by hyposmia (39.5%; 68/172) and sputum (39.5%; 68/172). Of the 68 individuals with hyposmia, 61 (90%) had accompanying symptoms such as hypogeusia, nasal congestion or rhinorrhoea. Fever (>37.5°C) was only observed in 20 (11.6%) individuals.ConclusionsAs much as one-fifth of individuals with COVID-19 remained asymptomatic from exposure to admission. Hyposmia was quite frequent among individuals with mild COVID-19, but fever was not. Social distancing should be strongly implemented to prevent disease transmission from asymptomatic individuals or those with mild and inconspicuous symptoms.
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Project description:It is unknown how much different are the clinical outcomes between asymptomatic and symptomatic patients with severe aortic stenosis (AS). In the CURRENT AS registry enrolling 3,815 consecutive patients with severe AS, we compared the long-term outcomes between 1808 asymptomatic and 1215 symptomatic patients (exertional dyspnea: N = 813, syncope: N = 136, and angina: N = 266) without heart failure (HF) hospitalization. Symptomatic patients had greater AS severity, and more depressed left ventricular function than asymptomatic patients without much difference in other baseline characteristics. During a median follow-up of 3.2 years, aortic valve replacement (AVR) was performed in 62% of symptomatic patients, and 38% of asymptomatic patients. The cumulative 5-year incidences for the primary outcome measure (a composite of aortic valve-related death or HF hospitalization) was higher in symptomatic patients than in asymptomatic patients (32.3% versus 27.6%, P < 0.001). After adjusting for AVR and other variables, the greater risk of symptomatic relative to asymptomatic patients for the primary outcome measure was significant (hazard ratio 1.64, 95% confidence interval 1.41-1.96, P < 0.001). In conclusions, the excess risk of symptomatic relative to asymptomatic patients with severe AS for the aortic valve-related event was significant. However, the prevalence of AVR in symptomatic patients was not optimal.
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Project description:We present an integrated analysis of urine and serum proteomics and clinical measurements in asymptomatic, mild/moderate, severe and convalescent cases of COVID-19. We identify the pattern of immune response during COVID-19 infection. The immune response is activated in asymptomatic infection, but is dysregulated in mild and severe COVID-19 patients. Our data suggest that the turning point depends on the function of myeloid cells and neutrophils. In addition, immune defects persist into the recovery stage, until 12 months after diagnosis. Moreover, disorders of cholesterol metabolism span the entire progression of the disease, starting from asymptomatic infection and lasting to recovery. Our data suggest that prolonged dysregulation of the immune response and cholesterol metabolism might be the pivotal causative agent of other potential sequelae. Our study provides a comprehensive understanding of COVID-19 immunopathogenesis, which is instructive for the development of early intervention strategies to ameliorate complex disease sequelae.
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Project description:BackgroundThere is dearth of information on COVID-19's impact on pregnant women. However, literature reported trends of COVID-19 differ, depending on the presence of clinical features upon presentation.ObjectiveThis systematic review aimed to assess differences in risk factors, management, complications, and pregnancy and perinatal outcomes in symptomatic vs. asymptomatic pregnant women with confirmed SARS-CoV-2 infection.MethodsA search was run on electronic databases to identify studies reporting COVID-19 in pregnancy. Meta-analysis was performed and odds ratios and mean difference with 95% confidence intervals were calculated using Review Manager 5.4. Review Prospero registration number CRD42020204662.ResultsWe included ten articles reporting data from 3158 pregnancies; with 1900 symptomatic and 1258 asymptomatic pregnant women. There was no significant difference in the mean age, gestational age, and body mass index between the two groups. The meta-analysis suggested that pregnant women who were obese (OR:1.37;95%CI:1.15 to 1.62), hypertensive (OR:2.07;95%CI:1.38 to 3.10) or had a respiratory disorder (OR:1.64;95%CI:1.25 to 2.16), were more likely to be symptomatic when infected with SARS-CoV-2. Pregnant women with Black (OR:1.48;95%CI:1.19 to 1.85) or Asian (OR:1.64;95%CI:1.23 to 2.18) ethnicity were more likely to be symptomatic while those with White ethnicity (OR:0.63;95%CI:0.52 to 0.76) were more likely to be asymptomatic. Cesarean-section delivery (OR:1.40;95%CI:1.17 to 1.67) was more likely amongst symptomatic pregnant women. The mean birthweight(g) (MD:240.51;95%CI:188.42 to 293.51), was significantly lower, while the odds of low birthweight (OR:1.85;95%CI:1.06 to 3.24) and preterm birth (< 37 weeks) (OR:2.10;95%CI:1.04 to 4.23) was higher amongst symptomatic pregnant women. Symptomatic pregnant women had a greater requirement for maternal ICU admission (OR:13.25;95%CI:5.60 to 31.34) and mechanical ventilation (OR:15.56;95%CI:2.96 to 81.70) while their neonates had a higher likelihood for Neonatal Intensive Care Unit admission (OR:1.96;95%CI:1.59 to 2.43). The management strategies in the included studies were poorly discussed, hence could not be analyzed.ConclusionThe evidence suggests that the presence of risk factors (co-morbidities and ethnicity) increased the likelihood of pregnant women being symptomatic. Higher odds of complications were also observed amongst symptomatic pregnant women. However, more adequately conducted studies with adjusted analysis and parallel comparison groups are required to reach conclusive findings.
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Project description:OBJECTIVES:The aim of this study was to elucidate patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance in the natural course of asymptomatic coronavirus disease 2019 (COVID-19). METHODS:Consecutive patients with non-severe COVID-19 were included retrospectively. Asymptomatic patients with a normal body temperature and no evidence of pneumonia throughout the disease course were assigned to the asymptomatic group. The reverse transcription PCR (RT-PCR) assay was repeated every two to five days after the first follow-up RT-PCR assay. Negative conversion was defined as two consecutive negative RT-PCR assay results within a 24-h interval. Rebound of the cycle threshold (Ct) value was defined as negative from the single RT-PCR assay and positive from the following assay. RESULTS:Among a total of 396 patients identified (median age 42.5 years (interquartile range (IQR) 25.0-55.0 years), 35.6% male), 68 (17.2%) were assigned to the asymptomatic group and 328 (82.8%) to the symptomatic group. The time until negative conversion was significantly shorter in the asymptomatic group than in the symptomatic group: median 14.5 days (IQR 11.0-21.0 days) and 18.0 days (IQR 15.0-22.0 days), respectively (p?=?0.001). Rebound of Ct values was observed in 78 patients (19.7%). CONCLUSIONS:Time until negative conversion is shorter in asymptomatic COVID-19 than in symptomatic COVID-19. Rebound of Ct values is not uncommon.
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Project description:The pandemic of coronavirus disease 2019 (COVID-19) has emerged as a major public health challenge worldwide. A comprehensive understanding of clinical characteristics and immune responses in asymptomatic carriers and symptomatic patients with COVID-19 is of great significance to the countermeasures of patients with COVID-19. Herein, we described the clinical information and laboratory findings of 43 individuals from Hunan Province, China, including 13 asymptomatic carriers and 10 symptomatic patients with COVID-19, as well as 20 healthy controls in the period from 25 January to 18 May 2020. The serum samples of these individuals were analyzed to measure the cytokine responses, receptor-binding domain (RBD), and nucleocapsid (N) protein-specific antibody titers, as well as SARS-CoV-2 neutralizing antibodies (nAbs). For cytokines, significantly higher Th1 cytokines including IL-2, IL-8, IL-12p70, IFN-γ, and TNF-α, as well as Th2 cytokines including IL-10 and IL-13 were observed in symptomatic patients compared with asymptomatic carriers. Compared with symptomatic patients, higher N-specific IgG4/IgG1 ratio and RBD-specific/N-specific IgG1 ratio were observed in asymptomatic carriers. Comparable nAbs were detected in both asymptomatic carriers and symptomatic patients with COVID-19. In the symptomatic group, nAbs in patients with underlying diseases were weaker than those of patients without underlying diseases. Our retrospective study will enrich and verify the clinical characteristics and serology diversities in asymptomatic carriers and symptomatic patients with COVID-19.
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