scholarly journals Transmissibility of COVID-19 depends on the viral load around onset in adult and symptomatic patients

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243597
Author(s):  
Hitoshi Kawasuji ◽  
Yusuke Takegoshi ◽  
Makito Kaneda ◽  
Akitoshi Ueno ◽  
Yuki Miyajima ◽  
...  
Keyword(s):  
Viral Load ◽  
Linear Regression ◽  
University Hospital ◽  
Sample Collection ◽  
Initial Sample ◽  
Median Viral Load ◽  
Secondary Transmission ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Non Linear

Objective To investigate the relationship between viral load and secondary transmission in novel coronavirus disease 2019 (COVID-19). Methods Epidemiological and clinical data were obtained from immunocompetent laboratory-confirmed patients with COVID-19 who were admitted to and/or from whom viral loads were measured at Toyama University Hospital. Using a case-control approach, index patients who transmitted the disease to at least one other patient were analysed as “cases” (index patients) compared with patients who were not the cause of secondary transmission (non-index patients, analysed as “controls”). The viral load time courses were assessed between the index and non-index symptomatic patients using non-linear regression employing a standard one-phase decay model. Results In total, 28 patients were included in the analysis. Median viral load at the initial sample collection was significantly higher in symptomatic than in asymptomatic patients and in adults than in children. Among symptomatic patients (n = 18), non-linear regression models showed that the estimated viral load at onset was higher in the index than in the non-index patients (median [95% confidence interval]: 6.6 [5.2–8.2] vs. 3.1 [1.5–4.8] log copies/μL, respectively). In adult (symptomatic and asymptomatic) patients (n = 21), median viral load at the initial sample collection was significantly higher in the index than in the non-index patients (p = 0.015, 3.3 vs. 1.8 log copies/μL, respectively). Conclusions High nasopharyngeal viral loads around onset may contribute to secondary transmission of COVID-19. Viral load may help provide a better understanding of why transmission is observed in some instances, but not in others, especially among household contacts.

scholarly journals Viral load dynamics in transmissible symptomatic patients with COVID-19

2020 ◽  
Author(s):  
Hitoshi Kawasuji ◽  
Yusuke Takegoshi ◽  
Makito Kaneda ◽  
Akitoshi Ueno ◽  
Yuki Miyajima ◽  
...  
Keyword(s):  
Viral Load ◽  
University Hospital ◽  
Linear Regression Models ◽  
Sample Collection ◽  
Median Viral Load ◽  
Secondary Transmission ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Novel Coronavirus ◽  
The Relationship

AbstractTo investigate the relationship between viral load and secondary transmission in novel coronavirus disease 2019 (COVID-19), we reviewed epidemiological and clinical data obtained from immunocompetent laboratory-confirmed patients with COVID-19 at Toyama University Hospital. In total, 28 patients were included in the analysis. Median viral load at the initial sample collection was significantly higher in adults than in children and in symptomatic than in asymptomatic patients. Among symptomatic patients, non-linear regression models showed that the estimated viral load at onset was higher in the index (patients who transmitted the disease to at least one other patient) than in the non-index patients (patients who were not the cause of secondary transmission; median [95% confidence interval]: 6.6 [5.2–8.2] vs. 3.1 [1.5–4.8] log copies/μL, respectively). High nasopharyngeal viral loads around onset may contribute to secondary transmission of COVID-19.Article Summary LineHigh nasopharyngeal viral load around the onset may contributes to secondary transmission of COVID-19.

scholarly journals Evaluation of the SARS-CoV-2 positivity ratio and upper respiratory tract viral load among asymptomatic individuals screened before hospitalization or surgery in Flanders, Belgium

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259908
Author(s):  
Laura Heireman ◽  
Steven Abrams ◽  
Peggy Bruynseels ◽  
Reinoud Cartuyvels ◽  
Lize Cuypers ◽  
...  
Keyword(s):  
Viral Load ◽  
Respiratory Tract ◽  
Age Group ◽  
Test Results ◽  
Rt Pcr ◽  
Median Viral Load ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Positivity Ratio ◽  
Second Wave

Introduction The incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in the Belgian community is mainly estimated based on test results of patients with coronavirus disease (COVID-19)-like symptoms. The aim of this study was to investigate the evolution of the SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) positivity ratio and distribution of viral loads within a cohort of asymptomatic patients screened prior hospitalization or surgery, stratified by age category. Materials/Methods We retrospectively studied data on SARS-CoV-2 real-time RT-PCR detection in respiratory tract samples of asymptomatic patients screened pre-hospitalization or pre-surgery in nine Belgian hospitals located in Flanders over a 12-month period (1 April 2020–31 March 2021). Results In total, 255925 SARS-CoV-2 RT-PCR test results and 2421 positive results for which a viral load was reported, were included in this study. An unweighted overall SARS-CoV-2 real-time RT-PCR positivity ratio of 1.27% was observed with strong spatiotemporal differences. SARS-CoV-2 circulated predominantly in 80+ year old individuals across all time periods except between the first and second COVID-19 wave and in 20–30 year old individuals before the second COVID-19 wave. In contrast to the first wave, a significantly higher positivity ratio was observed for the 20–40 age group in addition to the 80+ age group compared to the other age groups during the second wave. The median viral load follows a similar temporal evolution as the positivity rate with an increase ahead of the second wave and highest viral loads observed for 80+ year old individuals. Conclusion There was a high SARS-CoV-2 circulation among asymptomatic patients with a predominance and highest viral loads observed in the elderly. Moreover, ahead of the second COVID-19 wave an increase in median viral load was noted with the highest overall positivity ratio observed in 20–30 year old individuals, indicating they could have been the hidden drivers of this wave.

scholarly journals Implementing SARS-CoV-2 Rapid Antigen Testing in the Emergency Ward of a Swiss University Hospital: The INCREASE Study

2021 ◽  
Vol 9 (4) ◽  
pp. 798
Author(s):  
Giorgia Caruana ◽  
Antony Croxatto ◽  
Eleftheria Kampouri ◽  
Antonios Kritikos ◽  
Onya Opota ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
University Hospital ◽  
Lower Sensitivity ◽  
Clinical Settings ◽  
Rt Pcr ◽  
Emergency Ward ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Subjects ◽  
Antigen Testing

Following the Swiss Federal Office of Public Health (FOPH) authorization of the rapid antigen test (RAT), we implemented the use of the RAT in the emergency ward of our university hospital for patients’ cohorting. RAT triaging in association with RT-PCR allowed us to promptly isolate positive patients and save resources. Among 532 patients, overall sensitivities were 48.3% for Exdia and 41.2% for Standard Q®, PanbioTM and BD Veritor™. All RATs exhibited specificity above 99%. Sensitivity increased to 74.6%, 66.2%, 66.2% and 64.8% for Exdia, Standard Q®, PanbioTM and BD Veritor™, respectively, for viral loads above 105 copies/mL, to 100%, 97.8%, 96.6% and 95.6% for viral loads above 106 copies/mL and 100% for viral loads above 107 copies/mL. Sensitivity was significantly higher for patients with symptoms onset within four days (74.3%, 69.2%, 69.2% and 64%, respectively) versus patients with the evolution of symptoms longer than four days (36.8%, 21.1%, 21.1% and 23.7%, respectively). Among COVID-19 asymptomatic patients, sensitivity was 33%. All Immunoglobulin-A-positive patients resulted negative for RAT. The RAT might represent a useful resource in selected clinical settings as a complementary tool in RT-PCR for rapid patient triaging, but the lower sensitivity, especially in late presenters and COVID-19 asymptomatic subjects, must be taken into account.

scholarly journals Differential Kinetics of Cycle Threshold Values during Admission by Symptoms among Patients with Mild COVID-19: A Prospective Cohort Study

2021 ◽  
Vol 18 (15) ◽  
pp. 8181
Author(s):  
Teppei Sakano ◽  
Mitsuyoshi Urashima ◽  
Hiroyuki Takao ◽  
Kohei Takeshita ◽  
Hiroe Kobashi ◽  
...  
Keyword(s):  
Cohort Study ◽  
Viral Load ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Polymerase Chain Reaction Test ◽  
Cycle Threshold ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Individuals ◽  
Chain Reaction Test

In the coronavirus disease 2019 (COVID-19) pandemic, more than half of the cases of transmission may occur via asymptomatic individuals, which makes it difficult to contain. However, whether viral load in the throat during admission is different between asymptomatic and symptomatic patients is not well known. By conducting a prospective cohort study of patients with asymptomatic or mild COVID-19, cycle threshold (Ct) values of the polymerase chain reaction test for COVID-19 were examined every other day during admission. The Ct values during admission increased more steadily in symptomatic patients and febrile patients than in asymptomatic patients, with significance (p = 0.01 and p = 0.004, respectively), although the Ct values as a whole were not significantly different between the two groups. Moreover, the Ct values as a whole were higher in patients with dysosmia/dysgeusia than in those without it (p = 0.02), whereas they were lower in patients with a headache than those without (p = 0.01). Patients who were IgG-positive at discharge maintained higher Ct values, e.g., more than 35, during admission than those with IgG-negative (p = 0.03). Assuming that viral load and Ct values are negatively associated, the viral loads as a whole and their changes by time may be different by symptoms and immune reaction, i.e., IgG-positive at discharge.

scholarly journals Response to a Protease-Inhibitor (Ritonavir)-Containing Combination Antiretroviral Regimen in HIV-Infected Children

2003 ◽  
Vol 14 (2) ◽  
pp. 89-93
Author(s):  
Upton D Allen ◽  
Normand Lapointe ◽  
Stanley E Read ◽  
Jack C Forbes ◽  
Susan M King ◽  
...  
Keyword(s):  
Viral Load ◽  
Significant Proportion ◽  
Limited Data ◽  
Median Viral Load ◽  
Cd4 Counts ◽  
Viral Loads ◽  
Viral Load Monitoring ◽  
Load Monitoring ◽  
Perinatally Acquired ◽  
Combination Regimens

INTRODUCTION: The number of antiretroviral agents available for children who are failing existing therapy is limited. Data are lacking on the use of various combination regimens and the resulting viral load dynamics in such children.METHODS: Between March 1998 and March 2000, HIV-infected children younger than 18 years of age were studied in an open trial. The study regimen included ritonavir, with at least two drugs to which the virus was known or presumed to be sensitive. subjects were ritonavir-naive and were included if they had high viral loads while receiving antiretroviral therapy. Patients had clinical assessments, CD4 counts and viral load monitoring.RESULTS: Fifteen antiretroviral-experienced HIV-infected children were enrolled. Approximately 87% (13 of 15) had perinatally-acquired HIV; median age was 7.9 years (range 1.6 to 14.8). At enrolment, the median CD4 count was 557 cells/mm3(range 57 to 1702) and the median viral load was 72,600 copies/mL (range 3626 to 796,440). The majority of children (73.3%) had increases in CD4 counts within 12 weeks. During this period, the median increase in CD4 counts over baseline was 30.0%. Approximately 73% (eight of 11) of subjects with initial improvements in CD4 counts had sustained increases at 32 to 48 weeks. Over the first 12 weeks, 60% (nine of 15) had greater than 0.5 log10decreases in viral load. The improvement was sustained in 88.9% (eight of nine) of these patients at 32 to 48 weeks. Three patients discontinued therapy due to taste aversion.CONCLUSIONS: Among pediatric patients with high viral loads while on existing therapy, the ritonavir-containing regimen was generally well tolerated. In a significant proportion of patients, modification of therapy was associated with sustained improvements in viral loads and CD4 counts over 32 to 48 weeks.

scholarly journals Longitudinal comparison between plasma and seminal HIV-1 viral loads during antiretroviral treatment

2003 ◽  
Vol 36 (6) ◽  
pp. 689-694 ◽  
Author(s):  
Lauro Ferreira da Silva Pinto Neto ◽  
Nilo F.R. Vieira ◽  
Moacir Soprani ◽  
Carla B. Cunha ◽  
Valéria P. Cabral ◽  
...  
Keyword(s):  
Viral Load ◽  
Antiretroviral Treatment ◽  
Cd8 T Cell ◽  
Median Viral Load ◽  
Viral Loads ◽  
Cell Counts ◽  
Days Of Therapy ◽  
Longitudinal Comparison ◽  
The Impact ◽  
Hiv 1

This study was designed to investigate the impact of anti-retroviral therapy on both plasma and seminal HIV-1 viral loads and the correlation between viral loads in these compartments after treatment. Viral load, CD4+ and CD8+ T-cell counts were evaluated in paired plasma and semen samples from 36 antiretroviral therapy-naïve patients at baseline and on days 45, 90, and 180 of treatment. Slopes for blood and seminal viral loads in all treated patients were similar (p = 0.21). Median HIV-1 RNA titers in plasma and semen at baseline were 4.95 log10 and 4.48 log10 copies/ml, respectively. After 180 days of therapy, the median viral load declined to 3.15 log10 copies/ml (plasma) and 3.2 log10 copies/ml (semen). At this timepoint 22 patients presented HIV-1 viral load below 400 copies/ml in either plasma or semen, but only 9 had viral loads below 400 copies/ml in both compartments.

scholarly journals Viral Load of SARS-CoV-2 in Respiratory Aerosols Emitted by COVID-19 Patients while Breathing, Talking, and Singing

2021 ◽  
Author(s):  
Kristen K. Coleman ◽  
Douglas Jie Wen Tay ◽  
Kai Sen Tan ◽  
Sean Wei Xiang Ong ◽  
Than The Son ◽  
...  
Keyword(s):  
Viral Load ◽  
Significant Role ◽  
N Gene ◽  
Exhaled Breath ◽  
Indoor Environments ◽  
Future Studies ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Gene Copies ◽  
Study Participants

Background: Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. However, the detailed roles of coarse (>5μm) and fine (≤5μm) respiratory aerosols produced when breathing, talking, and singing are not well-understood. Methods: Using a G-II exhaled breath collector, we measured viral RNA in coarse and fine respiratory aerosols emitted by COVID-19 patients during 30 minutes of breathing, 15 minutes of talking, and 15 minutes of singing. Results: Among the 22 study participants, 13 (59%) emitted detectable levels of SARS-CoV-2 RNA in respiratory aerosols, including 3 asymptomatic patients and 1 presymptomatic patient. Viral loads ranged from 63 - 5,821 N gene copies per expiratory activity. Patients earlier in illness were more likely to emit detectable RNA, and loads differed significantly between breathing, talking, and singing. The largest proportion of SARS-CoV-2 RNA copies was emitted by singing (53%), followed by talking (41%) and breathing (6%). Overall, fine aerosols constituted 85% of the viral load detected in our study. Virus cultures were negative. Conclusions: Fine aerosols produced by talking and singing contain more SARS-CoV-2 copies than coarse aerosols and may play a significant role in the transmission of SARS-CoV-2. Exposure to fine aerosols should be mitigated, especially in indoor environments where airborne transmission of SARS-CoV-2 is likely to occur. Isolating viable SARS-CoV-2 from respiratory aerosol samples remains challenging, and whether this can be more easily accomplished for emerging SARS-CoV-2 variants is an important enquiry for future studies.

scholarly journals Air and environmental sampling for SARS-CoV-2 around hospitalized patients with coronavirus disease 2019 (COVID-19)

2020 ◽  
Vol 41 (11) ◽  
pp. 1258-1265 ◽  
Author(s):  
Vincent Chi-Chung Cheng ◽  
Shuk-Ching Wong ◽  
Veronica Wing-Man Chan ◽  
Simon Yung-Chun So ◽  
Jonathan Hon-Kwan Chen ◽  
...  
Keyword(s):  
Viral Load ◽  
Environmental Samples ◽  
Control Measures ◽  
Clinical Samples ◽  
Contamination Rate ◽  
Median Viral Load ◽  
Air Samples ◽  
Viral Loads ◽  
Infection Control Measures ◽  
Environmental Disinfection

AbstractBackground:The role of severe respiratory coronavirus virus 2 (SARS-CoV-2)–laden aerosols in the transmission of coronavirus disease 2019 (COVID-19) remains uncertain. Discordant findings of SARS-CoV-2 RNA in air samples were noted in early reports.Methods:Sampling of air close to 6 asymptomatic and symptomatic COVID-19 patients with and without surgical masks was performed with sampling devices using sterile gelatin filters. Frequently touched environmental surfaces near 21 patients were swabbed before daily environmental disinfection. The correlation between the viral loads of patients’ clinical samples and environmental samples was analyzed.Results:All air samples were negative for SARS-CoV-2 RNA in the 6 patients singly isolated inside airborne infection isolation rooms (AIIRs) with 12 air changes per hour. Of 377 environmental samples near 21 patients, 19 (5.0%) were positive by reverse-transcription polymerase chain reaction (RT-PCR) assay, with a median viral load of 9.2 × 102 copies/mL (range, 1.1 × 102 to 9.4 × 104 copies/mL). The contamination rate was highest on patients’ mobile phones (6 of 77, 7.8%), followed by bed rails (4 of 74, 5.4%) and toilet door handles (4 of 76, 5.3%). We detected a significant correlation between viral load ranges in clinical samples and positivity rate of environmental samples (P < .001).Conclusion:SARS-CoV-2 RNA was not detectable by air samplers, which suggests that the airborne route is not the predominant mode of transmission of SARS-CoV-2. Wearing a surgical mask, appropriate hand hygiene, and thorough environmental disinfection are sufficient infection control measures for COVID-19 patients isolated singly in AIIRs. However, this conclusion may not apply during aerosol-generating procedures or in cohort wards with large numbers of COVID-19 patients.

scholarly journals Evaluating the outcomes of enhanced adherence counselling intervention on clients with high viral loads in selected health facilities in Monze.

2021 ◽  
Author(s):  
Martha Kaira ◽  
Tresford Sikazwe ◽  
John Simwanza ◽  
Mowa Zambwe ◽  
Peter J. Chipimo
Keyword(s):  
Viral Load ◽  
High Viral Load ◽  
Cross Sectional Study ◽  
Health Facilities ◽  
Sample Collection ◽  
Viral Load Suppression ◽  
Cross Sectional ◽  
Viral Loads ◽  
Adherence Counselling ◽  
Counselling Intervention

To investigate the changes in Viral Load(VL) during Enhanced Adherence Counselling (EAC) sessions and its determinants among ART clients with unsuppressed VLs in Monze district. Method: A Cross-sectional study involving 616 HVL ART clients from 15 health facilities in Monze district which was conducted between October 1 2019 and March 30 2021. Results Out of 616 clients analysed, there was an improvement in viral load suppression following completion of EAC with a final outcome of 61% suppression. 28.7% remained unsuppressed. A total of 9.1% had no final viral load results documented and 0.2 % had been transferred out of their respective facilities and were not included in the study. Collection of repeat Viral loads was done on 84% of the clients with high viral load results while 16% had no record of sample collection. A total of 56 results were not received giving a result return of 89% from repeat samples collected. Females had a 40% likelihood of being unsuppressed at 95% CI (41% to 86%) compared to the males. Conclusion EAC improves the outcomes of HVLs and should be encouraged on all high viral clients. Programs should be developed to improve suppression in females on ART

scholarly journals Viral Loads Within 6 Weeks After Diagnosis of HIV Infection in Early and Later Stages: Observational Study Using National Surveillance Data (Preprint)

2018 ◽  
Author(s):  
Richard M. Selik ◽  
Laurie Linley
Keyword(s):  
Viral Load ◽  
Hiv Infection ◽  
Acute Infection ◽  
Antibody Test ◽  
Case Definition ◽  
Positive Test ◽  
Median Viral Load ◽  
Acute Hiv Infection ◽  
Viral Loads ◽  
Hiv 1

BACKGROUND Early (including acute) HIV infection is associated with viral loads higher than those in later stages. OBJECTIVE This study aimed to examine the association between acute infection and viral loads near the time of diagnosis using data reported to the US National HIV Surveillance System. METHODS We analyzed data on infections diagnosed in 2012-2016 and reported through December 2017. Diagnosis and staging were based on the 2014 US surveillance case definition for HIV infection. We divided early HIV-1 infection (stage 0) into two subcategories. Subcategory 0α: a negative or indeterminate HIV-1 antibody test was ≤60 days after the first confirmed positive HIV-1 test or a negative or indeterminate antibody test or qualitative HIV-1 nucleic acid test (NAT) was ≤180 days before the first positive test, the latter being a NAT or detectable viral load. Subcategory 0β: a negative or indeterminate antibody or qualitative NAT was ≤180 days before the first positive test, the latter being an HIV antibody or antigen/antibody test. We compared median earliest viral loads for each stage and subcategory in each of the first 6 weeks after diagnosis using only the earliest viral load for each individual. RESULTS Of 203,392 infections, 56.69% (115,297/203,392) were reported with a quantified earliest viral load within 6 weeks after diagnosis and criteria sufficient to determine the stage at diagnosis. Among 5081 infections at stage 0, the median earliest viral load fell from 694,000 copies/mL in week 1 to 125,022 in week 2 and 43,473 by week 6. Among 30,910 infections in stage 1, the median earliest viral load ranged 15,412-17,495. Among 42,784 infections in stage 2, the median viral load declined from 44,973 in week 1 to 38,497 in week 6. Among 36,522 infections in stage 3 (AIDS), the median viral load dropped from 205,862 in week 1 to 119,000 in week 6. The median earliest viral load in stage 0 subcategory 0α fell from 1,344,590 copies/mL in week 1 to 362,467 in week 2 and 47,320 in week 6, while that in subcategory 0β was 70,114 copies/mL in week 1 and then 32,033 to 44,067 in weeks 2-6. The median viral load in subcategory 0α was higher than that in subcategory 0β in each of the first 6 weeks after diagnosis (P<.001). CONCLUSIONS In the 1st week after diagnosis, viral loads in early infections are generally several times higher than those in later stages at diagnosis. By the 3rd week, however, most are lower than those in stage 3. High viral loads in early infection are much more common in subcategory 0α than in subcategory 0β, consistent with 0α comprising mostly acute infections and 0β comprising mostly postacute early infections. These findings may inform the prioritization of interventions for prevention.

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