scholarly journals Persistence of live virus in critically ill patients infected with SARS-COV-2: a prospective observational study

Critical Care ◽  
2022 ◽  
Vol 26 (1) ◽  
Author(s):  
Duane J. Funk ◽  
Jared Bullard ◽  
Sylvan Lother ◽  
Gloria Vazquez Grande ◽  
Lauren Garnett ◽  
...  
Keyword(s):  
Observational Study ◽  
Prospective Observational Study ◽  
Severity Of Illness ◽  
Vero Cells ◽  
Rt Pcr ◽  
Icu Patients ◽  
Live Virus ◽  
Cycle Threshold ◽  
Viral Culture ◽  
Culture Negative

Abstract Background Research on the duration of infectivity of ICU patients with COVID-19 has been sparse. Tests based on Reverse Transcriptase polymerase chain reaction (RT-PCR) detect both live virus and non-infectious viral RNA. We aimed to determine the duration of infectiousness based on viral culture of nasopharyngeal samples of patients with COVID-19. Methods Prospective observational study in adult intensive care units with a diagnosis of COVID-19 Pneumonia. Patients had repeated nasopharyngeal sampling performed after day 10 of ICU admission. Culture positive rate (based on viral culture on Vero cells in a level 4 lab) and Cycle threshold from RT-PCR were measured. Results Nine patients of the 108 samples (8.3%, 95% CI 3.9–15.2%) grew live virus at a median of 13 days (interquartile range 11–19) after their initial positive test. 74.1% of patients were RT-PCR positive but culture negative, and the remaining (17.6%) were RT-PCR and culture negative. Cycle threshold showed excellent ability to predict the presence of live virus, with a Ct < 25 with an AUC of 0.90 (95% CI 0.83–0.97, p < 0.001). The specificity of a Ct > 25 to predict negative viral culture was 100% (95% CI 70–100%). Conclusion 8.3% of our ICU patients with COVID-19 grew live virus at a median of 13 days post-initial positive RT-PCR test. Severity of illness, use of mechanical ventilation, and time between tests did not predict the presence of live virus. Cycle threshold of > 25 had the best ability to determine the lack of live virus in these patents.

scholarly journals Viral cultures for COVID-19 infectious potential assessment – a systematic review

2020 ◽  
Author(s):  
T Jefferson ◽  
E A Spencer ◽  
J Brassey ◽  
C Heneghan
Keyword(s):  
Rt Pcr ◽  
Live Virus ◽  
Cycle Threshold ◽  
Viral Loads ◽  
Additional Information ◽  
Viral Culture ◽  
Unit Increase ◽  
Specimen Test ◽  
Virus Culture ◽  
Infectious Potential

Abstract Objective to review the evidence from studies relating SARS-CoV-2 culture with the results of reverse transcriptase polymerase chain reaction (RT-PCR) and other variables which may influence the interpretation of the test, such as time from symptom onset Methods We searched LitCovid, medRxiv, Google Scholar and the WHO Covid-19 database for Covid-19 to 10 September 2020. We included studies attempting to culture or observe SARS-CoV-2 in specimens with RT-PCR positivity. Studies were dual extracted and the data summarised narratively by specimen type. Where necessary we contacted corresponding authors of included papers for additional information. We assessed quality using a modified QUADAS 2 risk of bias tool. Results We included 29 studies reporting attempts at culturing, or observing tissue infection by, SARS-CoV-2 in sputum, nasopharyngeal or oropharyngeal, urine, stool, blood and environmental specimens. The quality of the studies was moderate with lack of standardised reporting. The data suggest a relationship between the time from onset of symptom to the timing of the specimen test, cycle threshold (Ct) and symptom severity. Twelve studies reported that Ct values were significantly lower and log copies higher in specimens producing live virus culture. Two studies reported the odds of live virus culture reduced by approximately 33% for every one unit increase in Ct. Six of eight studies reported detectable RNA for longer than 14 days but infectious potential declined after day 8 even among cases with ongoing high viral loads. Four studies reported viral culture from stool specimens. Conclusion Complete live viruses are necessary for transmission, not the fragments identified by PCR. Prospective routine testing of reference and culture specimens and their relationship to symptoms, signs and patient co-factors should be used to define the reliability of PCR for assessing infectious potential. Those with high cycle threshold are unlikely to have infectious potential.

scholarly journals Viral cultures for COVID-19 infectivity assessment. Systematic review

2020 ◽  
Author(s):  
Tom Jefferson ◽  
Elizabeth Spencer ◽  
Jon Brassey ◽  
Carl Heneghan
Keyword(s):  
Strong Relationship ◽  
Threshold Level ◽  
Rt Pcr ◽  
Live Virus ◽  
Cycle Threshold ◽  
Viral Loads ◽  
Additional Information ◽  
Viral Culture ◽  
Unit Increase ◽  
Virus Culture

Objective To review the evidence from studies comparing SARS-CoV-2 culture, with the results of reverse transcriptase polymerase chain reaction (RT-PCR). Methods We searched LitCovid, medRxiv, Google Scholar and the WHO Covid-19 database for Covid-19 using the terms viral culture or viral replication and associated synonyms up to 10 September 2020. We carried out citation matching and included studies reporting attempts to culture or observe SARS-CoV-2 matching with cutoffs for RT-PCR positivity. One reviewer extracted data for each study and a second reviewer checked end edited the extraction and summarised the narratively by sample: fecal, respiratory, environment, blood or mixed. Where necessary we wrote to corresponding authors of the included or background papers for additional information. We assessed quality using a modified QUADAS 2 risk of bias tool. This is the fourth version of this review that was first published on the 4th of August and updated on the 21t of August, on the 3rd and 10th of September. Results We included 29 studies reporting culturing or observing tissue invasion by SARS-CoV in sputum, naso or oropharyngeal, urine, stool, blood and environmental samples from patients diagnosed with Covid-19. The data are suggestive of a relation between the time from collection of a specimen to test, cycle threshold and symptom severity. The quality of the studies was moderate with lack of standardised reporting. Twelve studies reported that Ct values were significantly lower and log copies higher in samples producing live virus culture. Five studies reported no growth in samples based on a Ct cut-off value. These values ranged from CT > 24 for no growth to Ct > 34 or more. Two studies report a strong relationship between Ct value and ability to recover infectious virus and that the odds of live virus culture reduced by 33% for every one unit increase in Ct. A cut-off RT-PCR Ct > 30 was associated with non-infectious samples. One study that analysed the NSP, N and E gene fragments of the PCR result reported different cut-off thresholds depending on the gene fragment analysed. The duration of RNA shedding detected by PCR was far longer compared to detection of live culture. Six out of eight studies reported RNA shedding for longer than 14 days. Yet, infectivity declines after day 8 even among cases with ongoing high viral loads. A very small proportion of people re-testing positive after hospital discharge or with high Ct are likely to be infectious. Conclusion Prospective routine testing of reference and culture specimens are necessary for each country involved in the pandemic to establish the usefulness and reliability of PCR for Covid-19 and its relation to patient factors. Infectivity is related to the date of onset of symptoms and cycle threshold level. A binary Yes / No approach to the interpretation RT-PCR unvalidated against viral culture will result in false positives with possible segregation of large numbers of people who are no longer infectious and hence not a threat to public health.

scholarly journals A rapid real-time polymerase chain reaction-based live virus microneutralization assay for detection of neutralizing antibodies against SARS-CoV-2 in blood/serum

2021 ◽  
Author(s):  
Syed Hani Abidi ◽  
Kehkeshan Imtiaz ◽  
Akbar Kanji ◽  
Shama Qaiser ◽  
Erum Khan ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vero Cells ◽  
Neutralization Assay ◽  
Dilution Method ◽  
Rt Pcr ◽  
Serum Samples ◽  
Live Virus ◽  
Viral Neutralization ◽  
Microneutralization Assay ◽  
Infected Cells

Abstract Background Individuals recovering from COVID-19 are shown to have antibodies against the Spike and other structural proteins. Antibodies against Spike have been shown to display viral neutralization. However, not all antibodies against Spike have neutralizing ability and some may be cross-reactive. There is a need for easy-to-use SARS-CoV-2 neutralizing assays that allow the determination of virus neutralizing activity in sera of individuals. Here we describe a PCR-based micro-neutralization assay that can be used to evaluate the viral neutralization titers of serum from SARS-CoV-2 infected individuals. Methods The SARS-CoV-2 strain used was isolated from a nasopharyngeal specimen of a COVID-19 case. The limiting dilution method was used to obtain a 50% tissue culture infective dose (TCID50) of Vero cells. For the micro‐neutralization assay, 19 serum samples, with positive IgG titers against Spike receptor binding domain (RBD) were tested. After 24 hours, infected cells were inspected for the presence of the cytopathic effect, then lysed and RNA RT-PCR of SARS-CoV-2. The Ct values were used to calculate percent neutralization/inhibition of SARS-CoV-2. Results Out of 19 samples, 13 samples gave 100% neutralization at all dilutions, while 4 samples gave neutralization at lower dilution, while one sample did not give any neutralization. The correlation between RBD OD and neutralization potential was found to be statistically correlated. Conclusion We describe a rapid RT-PCR based SARS-CoV-2 microneutralization assay for detection of neutralizing antibodies. This can effectively be used to test anti-viral activity of serum antibodies for investigation of both disease-driven and vaccine-induced responses.

scholarly journals Non-neurosurgical complications in traumatic neurosurgical ICU patients: A prospective observational study

2017 ◽  
Author(s):  
A. Khandelwal ◽  
K. Goyal ◽  
A. Hazarika ◽  
N. Sokhal ◽  
A. Bindra ◽  
...  
Keyword(s):  
Observational Study ◽  
Prospective Observational Study ◽  
Icu Patients

scholarly journals Higher clinical acuity and 7-day hospital mortality in non-COVID-19 acute medical admissions: prospective observational study

2020 ◽  
Author(s):  
Marcus J Lyall ◽  
Nazir I Lone
Keyword(s):  
Observational Study ◽  
Prospective Observational Study ◽  
Severity Of Illness ◽  
Medical Attention ◽  
Hospital Death ◽  
Hospital Inpatient ◽  
Day Hospital ◽  
Risk Of Death ◽  
Ambulance Transport ◽  
Emergency Ambulance

AbstractObjectivesTo understand the effect of COVID-19 lockdown measures on severity of illness and mortality in non-COVID-19 acute medical admissions.DesignA prospective observational studySetting3 large acute medical receiving units in NHS Lothian, Scotland. Participants: Non-covid-19 acute admissions (n = 1756) were examined over the first 31 days after the implementation of the COVID-19 lockdown policy in the United Kingdom on 23rd March 2019. Patients admitted over a matched interval in the previous 5 years were used as a comparator cohort (n = 14961).Main outcome measuresPatient demography, biochemical markers of clinical acuity and 7-day hospital inpatient mortality.ResultsNon-covid-19 acute medical admissions reduced by a mean 43.8% (95% CI 27.3, 59.4) across all 3 sites in comparison to the mean of the preceding 5 years P < 0.001. The reduction in admissions predominated in the over 75 age category and a greater proportion arrived by emergency ambulance transport. Non-covid-19 admissions during lockdown had a greater incidence of severe renal injury, hyperlactataemia and over twice the risk of hospital death within 7 days 5.01% vs 2.49% which persisted after adjustment for confounders (OR 2.17, 95% CI 1.70,2.73, P < 0.0001)ConclusionsThese data support current fears that patients are delaying seeking medical attention for acute illness which is associated with worsening clinical parameters and a higher risk of death following admission.

scholarly journals Predictors of illness severity in COVID-19 cases

2020 ◽  
Author(s):  
Reem A. AlDossary ◽  
Amani Alnimr ◽  
Reem Aljindan ◽  
Khaled Alkharsah ◽  
Ahmed Al-Qurayn ◽  
...  
Keyword(s):  
Case Fatality ◽  
Severity Of Illness ◽  
P Value ◽  
Rt Pcr ◽  
Asian Ethnicity ◽  
Cycle Threshold ◽  
Viral Shedding ◽  
Epidemiological Features ◽  
First Case ◽  
Clinical Presentations

Abstract Background Multiple studies worldwide reported the clinical and epidemiological features of coronavirus disease 2019 (COVID-19) with limited reports form the Middle East area. Methods This is an observational study to describe the clinical and epidemiological features of 341 COVID-19 cases in the Eastern Province of Saudi Arabia over the first three months from reporting the first case in the country and identify factors associated with severity of the illness. Results The median age was 45 years and males were twice as affected as females (p value < 0.0001). The duration of viral shedding ranged from 9 to 36 days. The most common clinical presentations include fever, shortness of breath, cough, myalgia, sore throat, vomiting, and headache. Severe and critical cases were significantly higher in males compared to females (23% vs 8.7%), senior adults (> 65 years), Bengali ethnicity, and in patient with com-morbidities including diabetes, hypertension, and dyslipidemia (p-value = 0.001). Furthermore, case fatality rate was found to be 10% and was significantly higher in male gender compared to female (13.8%vs 2.6%), and in Asian ethnicity (17.9%) compared to Arabs (6%) and African counterparts (0) (p-value = 0.002). No association was found between viral load represented by the RT-PCR cycle threshold (Ct) values and severity of illness. Conclusion Age, gender and ethnicity are important predictors of COVID-19 severity while Cycle threshold (Ct) of SARS-CoV-2 RT-PCR test cannot be used as a predictor of criticality of illness.

scholarly journals Vertical transmission and clinical outcome of the neonates born to SARS-CoV-2-positive mothers: a tertiary care hospital-based observational study

2021 ◽  
Vol 5 (1) ◽  
pp. e001193
Author(s):  
Pradeep Kumar ◽  
Fadila ◽  
Arun Prasad ◽  
Ambrin Akhtar ◽  
Bhabesh Kant Chaudhary ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Observational Study ◽  
Vertical Transmission ◽  
Prospective Observational Study ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Stable Condition ◽  
Nasopharyngeal Swab ◽  
Care Hospital ◽  
Rt Pcr

BackgroundNeonatal transmission of SARS-CoV-2 from positive mothers to their babies has been a real concern, opening the arena of research in this area.ObjectiveTo detect the possibility of vertical transmission of SARS-CoV-2 from COVID-19-positive mothers to their neonates and the clinicopathological outcome in them.DesignA single-centre, prospective, observational study involving 47 COVID-19-positive mothers and their neonates.SettingA tertiary care hospital in Eastern India.ParticipantsNeonates born to SARS-CoV-2-infected mothers.Main outcome measuresWe investigated the SARS-CoV-2 positivity rate by real-time reverse transcriptase-PCR (RT-PCR) done twice (on admission and after 24 hours of admission) in neonates born to SARS-CoV-2-positive mothers, who tested RT-PCR positive for this virus in their nasopharyngeal swab. Clinical outcome was also assessed in these neonates during their hospital stay.ResultsOut of 47 neonates born to SARS-CoV-2-positive mothers, four were SARS-CoV-2 positive by RT-PCR. All the neonates in our study were discharged home in stable condition after management of acute complications. None of them required readmission.ConclusionVertical transmission occurs in neonates born to COVID-19-positive mothers; however, the risk is small. Majority of the neonates remain asymptomatic with good clinical outcome.

Sepsis-Induced Myocardial Dysfunction in Pediatric Septic Shock: Prevalence, Predictors, and Outcome—A Prospective Observational Study

2021 ◽  
Author(s):  
Viresh S. Swami ◽  
Lalitha A. V. ◽  
Santu Ghosh ◽  
Mounika Reddy
Keyword(s):  
Septic Shock ◽  
Observational Study ◽  
Patient Outcomes ◽  
Prospective Observational Study ◽  
Point Of Care ◽  
Myocardial Dysfunction ◽  
Severity Of Illness ◽  
Serum Lactate ◽  
Lactate Levels ◽  
Organ Dysfunctions

AbstractThere is a paucity of literature on the prevalence, predictors, prognostic markers, and outcomes of sepsis-induced myocardial dysfunction (SMD) in pediatric septic shock. The objectives of our study were to estimate the prevalence of SMD in pediatric septic shock by point-of-care functional echocardiography (POCFE) and to study the association of SMD with severity of illness, organ dysfunctions, and outcomes. This prospective, observational study was conducted over a period of 1 year (from July 2018 to July 2019) in a 12-bed, tertiary pediatric intensive care unit (PICU) of an academic and referral hospital in South India. Children presenting with septic shock were enrolled in the study. POCFE was done within 6 hours of PICU admission and patients were categorized as having SMD based on POCFE findings. The prevalence of SMD (left ventricle ± right ventricle) was 32% (32/100). More than half of the children (54.5%) died in SMD group, whereas only 7.5% died in non-SMD group (p < 0.001). SMD was associated with higher organ dysfunctions, worse patient outcomes, and was found to be an independent predictor of mortality. The median lactate levels were higher in SMD group (3.15 [2.7, 5] vs. 2 [1.3, 2.7], p < 0.001) as compared with non-SMD group. We observed significantly lower median lactate clearance at 6 hours in SMD than non-SMD (30.0% [−14.44, 44.22] vs. 59.8% [45.83, 71.43], p < 0.001). Lactate levels at 6 hours with a threshold of 2.4 mmol/L was a good predictor of SMD with sensitivity and specificity of 73 and 80%, respectively. SMD is not an uncommon entity in children with septic shock. SMD was associated with worse patient outcomes, organ dysfunction, and mortality. Serum lactate trends may predict SMD and can be used as prognosticate markers as well.

Association of Microcirculation, Macrocirculation, and Severity of Illness in Septic Shock: A Prospective Observational Study to Identify Microcirculatory Targets Potentially Suitable for Guidance of Hemodynamic Therapy

2016 ◽  
Vol 33 (4) ◽  
pp. 256-266 ◽  
Author(s):  
Timo Sturm ◽  
Julia Leiblein ◽  
Verena Schneider-Lindner ◽  
Thomas Kirschning ◽  
Manfred Thiel
Keyword(s):  
Septic Shock ◽  
Observational Study ◽  
Oxygen Saturation ◽  
Fluid Balance ◽  
Prospective Observational Study ◽  
Lactate Concentration ◽  
Severity Of Illness ◽  
Surgical Intensive Care Unit ◽  
Surgical Intensive Care ◽  
Hemodynamic Therapy

Purpose: Clinically unapparent microcirculatory impairment is common and has a negative impact on septic shock, but specific therapy is not established so far. This prospective observational study aimed at identifying candidate parameters for microcirculatory-guided hemodynamic therapy. : NCT01530932. Materials and Methods: Microcirculatory flow and postcapillary venous oxygen saturation were detected during vaso-occlusive testing (VOT) on days 1 (T0), 2 (T24), and 4 (T72) in 20 patients with septic shock at a surgical intensive care unit using a laser Doppler spectrophotometry system (O2C). Results: Reperfusional maximal venous capillary oxygen saturation (SvcO2max) showed negative correlations with Simplified Acute Physiology Score II (SAPSII)/Sequential Organ Failure Assessment (SOFA) score, norepinephrine dosage, and lactate concentration and showed positive correlations with cardiac index (CI). At T24 and T72, SvcO2max was also inversely linked to fluid balance. With respect to any predictive value, SvcO2max and CI determined on day 1 (T0) were negatively correlated with SAPS II/SOFA on day 4 (T72). Moreover, SvcO2max measured on day 1 or day 2 was negatively correlated with cumulated fluid balance on day 4 ( r= −.472, P < .05 and r = −.829, P < .001). By contrast, CI neither on day 1 nor on day 2 was correlated with cumulated fluid balance on day 4 ( r = −.343, P = .17 and r = −.365, P = .15). Conclusion: In patients with septic shock, microcirculatory reserve as assessed by SvcO2max following VOT was impaired and negatively correlated with severity of illness and fluid balance. In contrast to CI, SvcO2max determined on day 1 or day 2 was significantly negatively correlated with cumulative fluid balance on day 4. Therefore, early microcirculatory measurement of SvcO2max might be superior to CI in guidance of sepsis therapy to avoid fluid overload. This has to be addressed in future clinical studies.

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