scholarly journals Detection of SARS-CoV-2 RNA in Bivalve Mollusks by Droplet Digital RT-PCR (dd RT-PCR)

Author(s):  
Andrea Mancusi ◽  
Federico Capuano ◽  
Santa Girardi ◽  
Orlandina Di Maro ◽  
Elisabetta Suffredini ◽  
...  

Bivalve shellfish are readily contaminated by human pathogens present in waters impacted by municipal sewage, and the detection of SARS-CoV-2 in feces of infected patients and in wastewater has drawn attention to the possible presence of the virus in bivalves. The aim of this study was to collect data on SARS-CoV-2 prevalence in bivalve mollusks from harvesting areas of Campania region. A total of 179 samples were collected between September 2019 and April 2021 and were tested using droplet digital RT-PCR (dd RT-PCR) and real-time RT-PCR. Combining results obtained with different assays, SARS-CoV-2 presence was detected in 27/179 (15.1%) of samples. A median viral concentration of 1.1 × 102 and 1.4 × 102 g.c./g was obtained using either Orf1b nsp14 or RdRp/gene E, respectively. Positive results were unevenly distributed among harvesting areas and over time, positive samples being more frequent after January 2021. Partial sequencing of the spike region was achieved for five samples, one of which displaying mutations characteristic of the Alpha variant (lineage B.1.1.7). This study confirms that bivalve mollusks may bioaccumulate SARS-CoV-2 to detectable levels and that they may represent a valuable approach to track SARS-CoV-2 in water bodies and to monitor outbreak trends and viral diversity.

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 623-627
Author(s):  
Kanishk K Adhit ◽  
Anjankar Ashish P ◽  
Siddhaarth K

In China, Wuhan in the province of China, COVID-19 a patient suffering from pneumonia was tested and to identify the cause, the throat swab of the patient was tested. On 7th January 2020 WHO declared the identification as COVID-19. And then it was proclaimed as a pandemic. It classically causes a respiratory illness presenting as a mild cough, fever and . However, several investigators have advocated the involvement of the gastrointestinal tract and liver in COVID-19 infection similar to other infections. Further research studies have shown results that are expanding the possibility of transmission because RT-PCR assessment has shown significant evidence for the presence of virus not only in samples but also in stool samples. Studies have shown that virus in stool samples have got positive results even after the illness has resolved, and two respiratory tests were done 24 hours after COVID-19 being tested negative. The review article the different findings of the clinical presentation of COVID-19. It sheds light on the effects of COVID-19 in the gastrointestinal system along with the reasons for the high possibility of transmission of COVID-19 through the route.


Author(s):  
Mar Muñoz-Chápuli Gutiérrez ◽  
Ana Durán-Vila ◽  
Javier Ruiz-Labarta ◽  
Pilar Payá-Martínez ◽  
Pilar Pintado Recarte ◽  
...  

Spain was one of the epicenters of the first wave of the COVID-19 pandemic. We describe in this article the design and results of a new telephone-and-telematic multiplatform model of systematic prenatal and postpartum follow-up for COVID-19-affected women implemented in a tertiary reference hospital in Madrid. We included patients with RT-PCR-confirmed COVID-19 during pregnancy or delivery from 10 March 2020 to 15 December 2020. We had a total of 211 obstetric patients: 148 (70.1%) were tested at the onset of suspicious clinical manifestations and 62 (29.4%) were tested in the context of routine screening. Of all the patients, 60 women (28.4%) were asymptomatic and 97 (46%) presented mild symptoms. Fifty-one women (24.2%) were admitted to our hospital for specific treatment because of moderate or severe symptoms. We had no missed cases and a good adherence. The mean number of calls per patient was 2.3. We performed 55 in-person visits. We analyzed the complexity of our program over time, showing a two-wave-like pattern. One patient was identified as needing hospitalization and we did not record major morbidity. Telemedicine programs are a strong and reproducible tool to reach to pregnant population affected by COVID-19, to assess its symptoms and severity, and to record for pregnancy-related symptoms both in an outpatient regime and after discharge from hospital.


2021 ◽  
Vol 26 (28) ◽  
Author(s):  
Samuel Alizon ◽  
Stéphanie Haim-Boukobza ◽  
Vincent Foulongne ◽  
Laura Verdurme ◽  
Sabine Trombert-Paolantoni ◽  
...  

We analysed 9,030 variant-specific RT-PCR tests performed on SARS-CoV-2-positive samples collected in France between 31 May and 21 June 2021. This analysis revealed rapid growth of the Delta variant in three of the 13 metropolitan French regions and estimated a +79% (95% confidence interval: 52–110%) transmission advantage compared with the Alpha variant. The next weeks will prove decisive and the magnitude of the estimated transmission advantages of the Delta variant could represent a major challenge for public health authorities.


Author(s):  
Yasuyuki Yamaoka ◽  
Hiroko Oe

In Japan, the policy for polymerase chain reaction (hereafter PCR) testing changed significantly after 7 May 2020; from 4 February to 6 May, PCR testing was limited to certain patients with severe symptoms. After 7 May, the PCR test was made available to a broader range of patients due to health insurance coverage. The study aims to test whether there is a significant relationship between the conditions under which PCR tests are performed, the number of tests after 7 May, and the positive results. Using a multiple regression model, we obtained the unexpected result even if we assume that PCR testing had been carried out during 4 February to 6 May at the same level as after 7 May. The number of positive cases would have been even lower than the actual number, which we have attained. This suggests that even if PCR testing had been plentiful throughout the entire period, the number of positives that would have been captured would not necessarily have been more significant than the actual number. This estimation might suggest that the infectivity of COVID-19 varied over time. It may suggest that, over time, the infectiousness and spreading power of COVID may be transformed. Therefore, further research investigating the epidemic impact of COVID is required, which is critical for humankind.


Author(s):  
Joel Hellewell ◽  
Timothy W. Russell ◽  
Rupert Beale ◽  
Gavin Kelly ◽  
Catherine Houlihan ◽  
...  

AbstractBackgroundRoutine asymptomatic testing using RT-PCR of people who interact with vulnerable populations, such as medical staff in hospitals or care workers in care homes, has been employed to help prevent outbreaks among vulnerable populations. Although the peak sensitivity of RT-PCR can be high, the probability of detecting an infection will vary throughout the course of an infection. The effectiveness of routine asymptomatic testing will therefore depend on testing frequency and how PCR detection varies over time.MethodsWe fitted a Bayesian statistical model to a dataset of twice weekly PCR tests of UK healthcare workers performed by self-administered nasopharyngeal swab, regardless of symptoms. We jointly estimated times of infection and the probability of a positive PCR test over time following infection, we then compared asymptomatic testing strategies by calculating the probability that a symptomatic infection is detected before symptom onset and the probability that an asymptomatic infection is detected within 7 days of infection.FindingsWe estimated that the probability that the PCR test detected infection peaked at 77% (54 - 88%) 4 days after infection, decreasing to 50% (38 - 65%) by 10 days after infection. Our results suggest a substantially higher probability of detecting infections 1–3 days after infection than previously published estimates. We estimated that testing every other day would detect 57% (33-76%) of symptomatic cases prior to onset and 94% (75-99%) of asymptomatic cases within 7 days if test results were returned within a day.InterpretationOur results suggest that routine asymptomatic testing can enable detection of a high proportion of infected individuals early in their infection, provided that the testing is frequent and the time from testing to notification of results is sufficiently fast.FundingWellcome Trust, National Institute for Health Research (NIHR) Health Protection Research Unit, Medical Research Council (UKRI)


Author(s):  
Oskar Ekelund ◽  
Kim Ekblom ◽  
Sofia Somajo ◽  
Johanna Pattison-Granberg ◽  
Karl Olsson ◽  
...  

Background: The recently launched high-throughput assays for the detection of antibodies against SARS-CoV-2 may change the managing strategies for the COVID-19 pandemic. This study aimed at investigating the performance of three high-throughput assays and one rapid lateral flow test relative to the recommended criteria defined by regulatory authorities. Methods: A total of 133 samples, including 100 pre-pandemic samples, 20 samples from SARS-CoV-2 RT-PCR positive individuals, and 13 potentially cross-reactive samples were analysed with SARS-CoV-2 IgG (Abbott), Elecsys Anti-SARS-CoV-2 (Roche), LIAISON SARS-CoV-2 S1/S2 IgG (DiaSorin) and 2019-nCOV IgG/IgM Rapid Test (Dynamiker Biotechnology Co). Results: All assays performed with a high level of specificity; however, only Abbott reached 100% (95% CI 96.3-100). The pre-pandemic samples analysed with Roche, DiaSorin and Dynamiker Biotechnology resulted in two to three false-positive results per method (specificity 96.9-98.0%). Sensitivity differed more between the assays, Roche exhibiting the highest sensitivity (100%, CI 83.9-100). The corresponding figures for Abbott, DiaSorin and Dynamiker Biotechnology were 85.0%, 77.8% and 75.0%, respectively. Conclusions: The results of the evaluated SARS-CoV-2 assays vary considerably as well as their ability to fulfil the performance criteria proposed by regulatory authorities. Introduction into clinical use in low-prevalent settings, should therefore, be made with caution.


Author(s):  
Mohammed Alsuhaibani ◽  
Takaaki Kobayashi ◽  
Alexandra Trannel ◽  
Stephanie Holley ◽  
Oluchi J. Abosi ◽  
...  

Abstract Objective: Patients admitted to the hospital may unknowingly carry SARS-CoV-2 and hospitals have implemented SARS-CoV-2 admission screening. However, because SARS-CoV-2 RT-PCR may remain positive for months after infection, positive results may represent active or past infection. We determined the prevalence and infectiousness of patients who were admitted for reasons unrelated to COVID-19 but tested positive on admission screening. Methods: We conducted an observational study at the University of Iowa Hospitals & Clinics from July 7 to October 25, 2020. All patients admitted without suspicion of COVID-19 infection were included and medical records of those with a positive admission screening test were reviewed. Infectiousness was determined using patient history, PCR cycle threshold (Ct) value, and serology. Results: A total of 5,913 patients were screened and admitted for reasons unrelated to COVID-19. Of these, 101 had positive admission RT-PCR results. Thirty-six patient were excluded because they had respiratory signs/symptoms on admission on chart review. Sixty-five patients (1.1%) did not have respiratory symptoms. A total of 55 patients had Ct values available and were included in this analysis. The median age was 56 years, and (51%) were male. Our assessment revealed that 23 patients (42%) were likely infectious. The median duration of in-hospital isolation was five days for those likely infectious and two days for those deemed non-infectious. Conclusions: COVID-19 infection was infrequent among patients admitted for reasons unrelated to COVID-19. An assessment of the likelihood of infectiousness using clinical history, RT-PCR Ct values, and serology may help discontinue isolation and conserve resources.


Author(s):  
sara sadr ◽  
Melika Arab Bafrani ◽  
Alireza Abdollahi ◽  
SeyedAhmad SeyedAlinaghi ◽  
Esmaeil Mohammadnejad ◽  
...  

Objectives Possibility of reinfection with SARS-CoV-2 changes our view on herd immunity and vaccination, and can impact worldwide quarantine policies. We performed RT-PCR follow-up studies on recovered patients to assess possible development of reinfections and re-positivity. Method During a 6-month period, 202 PCR-confirmed recovering COVID-19 patients entered this study. Follow-up RT-PCR tests and symptoms assessment were performed one month after the initial Positive results. patients who tested negative were tested again one and three months later. The Serum IgG and IgM levels were measured in the last follow-up session. Results In the first two follow-up sessions, 82 patients continued their participation, of which four patients tasted positive. In the second follow-up 44 patients participated, three of whom tested positive. None of the patients who tested positive in the first and second follow-up session were symptomatic. In the last session, 32 patients were tested and four patients were positive, three of them were mildly symptomatic and all of them were positive for IgG. Conclusion A positive RT-PCR in a recovering patient may represent reinfection. While we did not have the resources to prove reinfection by genetic sequencing of the infective viruses, we believe presence of mild symptoms in the three patients who tested positive over 100 days after becoming asymptomatic, can be diagnosed as reinfection. The IgG may have abated the symptoms of the reinfection, without providing complete protection.


1977 ◽  
Vol 45 (3) ◽  
pp. 827-834
Author(s):  
Richard E. Kopelman ◽  
James J. Pantaleno

It is widely held that the professional athlete who is traded tends to perform better against the trading team than against other teams. Two psychological explanations for this hypothesis were advanced (a separation-hostility mechanism and an esteem loss-counteraction mechanism). Data were examined for 47 (30) professional baseball players over a 2-yr. (3-yr.) period. Support for the hypothesis was weak across the entire sample; however, some support appeared among players who (a) were traded for the first time, (b) had long tenure with the trading team, (c) were young, and (d) had high ability. Somewhat stronger positive results were found for individuals who met two or more of the conditions favorable to the hypothesis. As predicted, results attenuated over time.


2020 ◽  
Author(s):  
YANFANG LIU ◽  
LINA LIU ◽  
YE WANG ◽  
XINYANG DU ◽  
HONG MA ◽  
...  

Abstract BackgroundCOVID-19 associated with SARS-CoV-2 infection is of outbreak worldwide. This project aimed to provide clinical features, treatment advice and risk factors of patients diagnosed with COVID-19.MethodsIn this study, we analyzed 109 patients with confirmed COVID-19. We compared the relevant data of patients over 60 years old and under 60 years old, analyzed the data of patients with chronic diseases, and clarified the importance of the combination of laboratory examination and CT diagnosis.ResultsMost of patients 59(54.1%) had no fever. 100(91.7%) of patients required supplemental O2, and their SpO2 values reached normal after oxygen therapy. 72 (66.1%) patients were over 60 years old, and they were more likely to develop respiratory symptoms. Among all patients, only 14 (12.8%) patients were positive for anti-SARS-CoV-2 antibody, SARS-COV-2 RT-PCR assay and CT diagnosis.Conclusion(1) O2 supplement therapy plays an important role in the treatment of COVID-19 patients.(2) People over 60 years old or(and) having chronic diseases are risk factors of SARS-CoV-2 infection.(3) Most patients infected with SARS-CoV-2 have no fever symptoms.(4) We recommend that CT positive results be included in the confirmed diagnosis criteria, which is important for the diagnosis of COVID-19.


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