scholarly journals COVID-19 outbreak prevention by early containment in Shantou, China

2020 ◽  
Vol 14 (07) ◽  
pp. 742-747
Author(s):  
Xubin Zhang ◽  
Dangui Zhang ◽  
Chi Zhang ◽  
Lijun Yao ◽  
Lu Xu ◽  
...  
Keyword(s):  
Mainland China ◽  
Lag Time ◽  
Contact Tracing ◽  
Linear Regression Models ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Community Screening ◽  
First Case ◽  
Containment Measures ◽  
Close Contacts

Introduction: To report about the successful outbreak containment of COVID-19 in Shantou, one of the prefectural cities of Guangdong province in the mainland China. Methodology: All patients confirmed as having COVID-19 between 23 January and 25 March 2020 by RT-PCR assay in the clinical lab of Shantou CDC were included and divided into three groups based on the source of identification: hospital diagnosis, contact tracing, and community screening. Collected data was analyzed and compared among these three groups. Results: A total of 25 COVID-19 cases were identified in Shantou. The first case was identified on 14 January 2020 at one of two COVID-19 dedicated hospitals in Shantou. The majority of the cases were either imported from Wuhan or linked to Wuhan/Hubei. The median lag time for diagnosis (i.e., the time between symptom onset and case confirmation) was 2 days (IQR, 2.0-4.0) for all cases, 9 days (IQR, 7.0-10.0) for the cases diagnosed in hospitals, 2 days (IQR, 1.5-2.0) for the cases in contact tracing, and 4 days (IQR, 2.5-4.5) for cases in community screening, with a significantly longer diagnosis lag time in hospitals (p = 0.003). Multivariate linear regression models showed larger family size and severe cases as the significant predictor for increasing number of close contacts. Conclusions: The current pandemic appears to exist for an uncertain period. The early containment measures applied in Shantou, a city with insufficient healthcare resources for COVID-19, seems to be appropriate for cities or areas with similar profiles.

scholarly journals COVID-19 in a Rural Community: Outbreak Dynamics, Contact Tracing and Environmental RNA

2020 ◽  
Author(s):  
Isabel G. Fernández de Mera ◽  
Francisco J. Rodríguez del Río ◽  
José de la Fuente ◽  
Marta Pérez Sancho ◽  
Dolores Hervas ◽  
...  
Keyword(s):  
Rural Community ◽  
Public Service ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Rna Surveillance ◽  
Petrol Station ◽  
Early Testing ◽  
Resource Deployment ◽  
The Village ◽  
Close Contacts

Background: Since March 2020, Spain is severely hit by the ongoing pandemic of coronavirus disease 19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Understanding and disrupting the early transmission dynamics of the infection is crucial for impeding sustained transmission. Methods: We recorded all COVID-19 cases and traced their contacts in an isolated rural community. We also sampled 10 households, 6 public service sites and the wastewater from the village sewage for environmental SARS-CoV-2 RNA. Results: The first village patient diagnosed with COVID-19-compatible symptoms occurred on March 3, 2020, twelve days before lockdown. A peak of 39 cases occurred on March 30. By May 15, the accumulated number of symptomatic cases was 53 (6% of the population), of which only 22 (41%) had been tested and confirmed by RT-PCR as SARS-CoV-2 infected, including 16 hospitalized patients. Contacts (n=144) were six times more likely to develop symptoms. Environmental sampling detected SARS-CoV-2 RNA in two households with known active cases and in two public service sites: the petrol station and the pharmacy. Samples from other sites and the wastewater tested negative. Conclusions: The low proportion of patients tested by RT-PCR calls for urgent changes in disease management. We propose that early testing of all cases and their close contacts would reduce infection spread, reducing the disease burden and fatalities. In a context of restricted testing, environmental RNA surveillance might prove useful for early warning and to identify high-risk settings enabling a targeted resource deployment.

scholarly journals Salivary detection of COVID-19. Clinical performance of oral sponge sampling for SARS-CoV-2 testing

2021 ◽  
Author(s):  
Charles Hugo Marquette ◽  
Jacques Boutros ◽  
Jonathan Benzaquen ◽  
Marius Ilié ◽  
Mickelina Labaky ◽  
...  
Keyword(s):  
Mass Screening ◽  
Clinical Performance ◽  
Close Contact ◽  
Low Cost ◽  
Sampling Technique ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Community Based ◽  
Attending Physician ◽  
Close Contacts

ABSTRACTBackgroundThe current diagnostic standard for coronavirus 2019 disease (COVID-19) is reverse transcriptase-polymerase chain reaction (RT-PCR) testing with naso-pharyngeal (NP) swabs. The invasiveness and need for trained personnel make the NP technique unsuited for repeated community-based mass screening. We developed a technique to collect saliva in a simple and easy way with the sponges that are usually used for tamponade of epistaxis. This study was carried out to validate the clinical performance of oral sponge (OS) sampling for SARS-CoV-2 testing.MethodsOver a period of 22 weeks, we collected prospectively 409 paired NP and OS samples from consecutive subjects presenting to a public community-based free screening center. Subjects were referred by their attending physician because of recent COVID-19 symptoms (n=147) or by the contact tracing staff of the French public health insurance since they were considered as close contacts of a laboratory-confirmed COVID-19 case (n=262).ResultsIn symptomatic subjects, RT-PCR SARS-CoV-2 testing with OS showed a 96.5% (95%CI: 89.6-94.8) concordance with NP testing, and, a 93.3% [95%CI: 89.1-97.3] sensitivity. In close contacts the NP-OS concordance (93.8% [95%CI: 90.9-96.7]) and OS sensitivity (71.9% [95%CI: 66.5-77.3]) were slightly lower.ConclusionThese results strongly suggest that OS testing is a straightforward, low-cost and high-throughput sampling method that can be used for frequent RT-PCR testing of COVID-19 patients and mass screening of populations.Summary of the “take home” messageOS sampling for SARS-CoV2 RT-PCR is an easy to perform, straightforward self-administered sampling technique, which has a sensitivity of up to 93.3% in symptomatic patients and 71% in close contact subjects.

scholarly journals THE FIRST CASE OF Angiostrongylus cantonensis EOSINOPHILIC MENINGITIS DIAGNOSED IN THE CITY OF SÃO PAULO, BRAZIL

2013 ◽  
Vol 55 (2) ◽  
pp. 129-132 ◽  
Author(s):  
Maria Cristina Carvalho do Espírito-Santo ◽  
Pedro Luiz Silva Pinto ◽  
Dan Jesse Gonçalves da Mota ◽  
Ronaldo César Borges Gryschek
Keyword(s):  
Pediatric Emergency ◽  
Sao Paulo ◽  
Angiostrongylus Cantonensis ◽  
Eosinophilic Meningitis ◽  
São Paulo ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Csf Analysis ◽  
First Case ◽  
The City

Introduction:Angiostrongylus cantonensis is a natural parasite found in lung arteries of rats, which in humans may cause eosinophilic meningitis. Objective: To report the first case of eosinophilic meningitis caused by Angiostrongylus cantonensis in the city of São Paulo, Brazil. Case report: A male patient, 11 years old, living in the southern area of São Paulo, was admitted to the Pediatric Emergency Department with ongoing headaches for three days, but no fever or any other complaint. The presence of snails and rodents was reported in the peridomicile. The child was awake, lucid, oriented; muscular strength preserved, isochoric, photo reagent pupils and terminal nuchal rigidity - Glasgow Coma Scale (GCS) = 15. The laboratory tests showed a mild leukocytosis with 1736 eosinophils/mm3 and the CSF analysis disclosed 160 leukocytes/mm3 with 36% of eosinophils. The bacterial culture was negative. Computed Cerebral Tomography showed no alterations. The RT-PCR assay for detecting Angiostrongylus cantonensis larvae and DNA was negative. ELISA antibodies for IgG anti-A. cantonensis was negative in serum and undetermined in CSF and samples collected five days after the onset of symptoms. Seroconversion was observed in the sample collected 135 days later. Conclusion: the epidemiological and clinical data, the CSF alterations with eosinophilia and the seroconversion strongly suggest Angiostrongylus cantonensis eosinophilic meningitis.

scholarly journals Salivary detection of COVID-19. Clinical performance of oral sponge sampling for SARS-CoV-2 testing

2021 ◽  
pp. 00396-2021
Author(s):  
Jacques Boutros ◽  
Jonathan Benzaquen ◽  
Charles Hugo Marquette ◽  
Marius Ilié ◽  
Mickelina Labaky ◽  
...  
Keyword(s):  
Mass Screening ◽  
Sampling Method ◽  
Clinical Performance ◽  
Low Cost ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Community Based ◽  
Polymerase Chain ◽  
Attending Physician ◽  
Close Contacts

BackgroundThe current diagnostic standard for coronavirus 2019 disease (COVID-19) is reverse transcriptase-polymerase chain reaction (RT-PCR) testing with naso-pharyngeal (NP) swabs. The invasiveness and need for trained personnel make the NP technique unsuited for repeated community-based mass screening. We developed a technique to collect saliva in a simple and easy way with the sponges that are usually used for tamponade of epistaxis. This study was carried out to validate the clinical performance of oral sponge (OS) sampling for SARS-CoV-2 testing.MethodsOver a period of 22 weeks, we collected prospectively 409 paired NP and OS samples from consecutive subjects presenting to a public community-based free screening center. Subjects were referred by their attending physician because of recent COVID-19 symptoms (n=147) or by the contact tracing staff of the French public health insurance since they were considered as close contacts of a laboratory-confirmed COVID-19 case (n=262).ResultsIn symptomatic subjects, RT-PCR SARS-CoV-2 testing with OS showed a 96.5% (95%CI: 89.6–94.8) concordance with NP testing, and, a 93.2% (95%CI: 89.1–97.3)] sensitivity when using the IdyllaTM platform and a sensitivity of 76.3% [69.4–83.2] on the Synlab Barla laboratory platform. In close contacts the NP-OS concordance (93.8% [95%CI: 90.9–96.7]) and OS sensitivity (71.9% [95%CI: 66.5–77.3]) were slightly lower.ConclusionThese results strongly suggest that OS testing is a straightforward, low-cost and high-throughput sampling method that can be used for frequent RT-PCR testing of COVID-19 patients and mass screening of populations.

scholarly journals LB7. Contract Tracing Investigation Following First Case of Andes Virus in the United States

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S761-S762
Author(s):  
Aaron Kofman ◽  
Paula Eggers ◽  
Anne Kjemtrup ◽  
Rebecca Hall ◽  
Shelley Brown ◽  
...  
Keyword(s):  
High Risk ◽  
Incubation Period ◽  
Close Contact ◽  
The United States ◽  
Body Fluids ◽  
Low Risk ◽  
Contact Tracing ◽  
Rt Pcr ◽  
First Case ◽  
Andes Virus

Abstract Background In January 2018, a patient admitted to a Delaware hospital tested positive for New World hantavirus by IgM and IgG ELISA. Subsequent testing by CDC’s Viral Special Pathogens Branch (VSPB) confirmed Andes virus (ANDV) by reverse transcription polymerase chain reaction (RT-PCR) and sequencing. ANDV is transmitted to humans through contact with long-tailed rice rats endemic to Argentina and Chile. Unlike other hantavirus species, ANDV can be transmitted person to person, but transmission is typically limited to close contacts of ill persons. Because of this risk, a contact tracing investigation was initiated by CDC, state and county health departments. Method A suspect case was defined as a person with close contact with the traveler who became ill within the maximum incubation period (42 days) following last contact. A high-risk contact was defined as a person with exposure to the traveler’s body fluids. A low-risk contact was defined as a person who had provided care or in-flight service to, or was seated near the traveler for at least 1 hour, in the absence of exposure to body fluids. All contacts were advised to self-monitor their temperature daily for 42 days from last contact, and to seek medical care for any of the specified symptoms. Contacts that developed symptoms were tested for ANDV by RT-PCR and serology by VSPB. Result Fifty-three contacts were identified in six states; 51 were successfully reached. Of these, 28 were healthcare workers, 15 were airline contacts, seven were acquaintances of the traveler, and one was a hospital roommate. Two high-risk contacts were identified, both of whom remained asymptomatic. Six low-risk contacts reported influenza-like illness, diarrhea, or mild rhinitis during the incubation period. All six symptomatic low-risk contacts tested negative for ANDV by PCR, IgM, and IgG. The remaining low-risk contacts remained asymptomatic. Conclusion Hospitalized patients with ANDV should be managed with standard, contact, and droplet precautions. While the risk of human-to-human transmission is low, contact tracing should be considered to identify potential cases and limit additional exposures. Health providers should consider ANDV in returning travelers with a nonspecific febrile or acute respiratory illness who have traveled to the Andes region of Argentina or Chile in the preceding 6 weeks. Disclosures All authors: No reported disclosures.

scholarly journals Analysis of external quality assessment samples revealed crucial performance differences between commercial RT-PCR assays for SARS-CoV-2 detection when taking extraction methods and real-time-PCR instruments into account

2020 ◽  
Author(s):  
Monika Malecki ◽  
Jessica Luesebrink ◽  
Andreas Wendel ◽  
Frauke Mattner
Keyword(s):  
Real Time ◽  
External Quality Assessment ◽  
False Negative ◽  
Clinical Results ◽  
Extraction Methods ◽  
Contact Tracing ◽  
Clinical Settings ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Wide Range

In limelight of the ongoing pandemic SARS-CoV-2 testing is critical for the diagnosis of infected patients, contact-tracing and mitigating the transmission. Diagnostic laboratories are expected to provide appropriate testing with maximum accuracy. Real-time reverse transcriptase PCR (RT-PCR) is the diagnostic standard yet many commercial diagnostic kits have become available. However, only a handful of studies have reviewed their performance in clinical settings. The aim of this study was to compare the performance of the overall analytical matrix including the extraction kit (BD MAX, Promega, Qiagen), the PCR instrument (Agilent Mx3005P, BD MAX, Qiagen Rotor-Gene, Roche Cobas z 480) and the RT-PCR assay (Altona Diagnostics, CerTest Biotec, R-Biopharm AG) using predefined samples from proficiency testing organizers. The greatest difference of the Ct values between the matrices was 9 cycles. One borderline sample could not be detected by 3 out of 12 analytical matrices and yielded a false negative result. We therefore conclude that diagnostic laboratories should take the complete analytical matrix in addition to the performance values published by the manufacturer for a respective RT-PCR kit into account. With limited resources laboratories have to validate a wide range of kits to determine appropriate analytical matrices for detecting SARS-CoV-2 reliably. The interpretation of clinical results has to be adapted accordingly.

scholarly journals Diagnostic accuracy of rapid antigen tests in pre-/asymptomatic close contacts of individuals with a confirmed SARS-CoV-2 infection

2021 ◽  
Author(s):  
E Schuit ◽  
IK Veldhuijzen ◽  
RP Venekamp ◽  
W van den Bijllaardt ◽  
SD Pas ◽  
...  
Keyword(s):  
Viral Load ◽  
Diagnostic Accuracy ◽  
Contact Tracing ◽  
Test Accuracy ◽  
Rt Pcr ◽  
Cross Sectional ◽  
Gene Copies ◽  
Registration Number ◽  
Antigen Tests ◽  
Close Contacts

AbstractBackgroundPre-/asymptomatic close contacts of SARS-CoV-2 infected individuals were tested at day 5 after contact by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Diagnostic accuracy of antigen-detecting rapid diagnostic tests (Ag-RDT) in pre-/asymptomatic close contacts was up till now unknown.MethodsWe performed a prospective cross-sectional diagnostic test accuracy study. Close contacts (e.g. selected via the test-and-trace program or contact tracing app) aged ≥16 years and asymptomatic when requesting a test, were included consecutively and tested at day 5 at four Dutch public health service test sites. We evaluated two Ag-RDTs (BD Veritor™ System Ag-RDT (BD), and Roche/SD Biosensor Ag-RDT (SD-B)) with RT-PCR as the reference standard. Virus culture was performed in RT-PCR positive individuals to determine the viral load cut-off above which 95% was culture positive, as a proxy of infectiousness.ResultsOf 2,678 BD-tested individuals, 233 (8.7%) were RT-PCR positive and BD detected 149 (sensitivity 63.9%; 95% confidence interval 57.4%-70.1%). Out of 1,596 SD-B-tested individuals, 132 (8.3%) were RT-PCR positive and SD-B detected 83 (sensitivity 62.9%; 54.0%-71.1%). When applying an infectiousness viral load cut-off ≥ 5.2 log10 gene copies/mL, the sensitivity was 90.1% (84.2%-94.4%) for BD, 86.8% (78.1% to 93.0%) for SD-B overall, and 88.1% (80.5%-93.5%) for BD, 85.1% (74.3%-92.6%) for SD-B for those still asymptomatic at the actual time of sampling. Specificity was >99% for both Ag-RDTs in all analyses.ConclusionsThe sensitivity for detecting SARS-CoV-2 of both Ag-RDTs in pre-/asymptomatic close contacts is over 60%, increasing to over 85% after applying an infectiousness viral load cut-off.Trial registration numberNot applicable. A study protocol is available upon request.

scholarly journals The impact of containment measures and air temperature on mitigating COVID-19 transmission: non-classical SEIR modeling and analysis

2020 ◽  
Author(s):  
Di Liu ◽  
Qidong Tai ◽  
Yaping Wang ◽  
Miao Pu ◽  
Sikai Ge ◽  
...  
Keyword(s):  
Air Temperature ◽  
Model Simulation ◽  
Transmission Rate ◽  
Mainland China ◽  
Contact Tracing ◽  
Modeling And Analysis ◽  
Optimal Temperature Range ◽  
Containment Measures ◽  
China Model ◽  
The Impact

Early non-pharmaceutical interventions (NPIs) are crucial to prevent and control of COVID-19 pandemic. We established a stochastic non-classical SEIR NPIs model (ScEIQRsh) which can quantify the three kinds of NPIs measures simultaneously to mimic the clustered intra-family or intra-acquaintance spreading pattern of COVID-19 under the effective integrated NPIs in Mainland China. Model simulation demonstrated that measures to diminish contactable susceptible (Sc), such as home confinement, travel constraint, social distancing etc. and measures to avoid delay of diagnosis and hospitalized isolation (η) were more effective but consumptive than contact tracing (κ, ρ). From fitted model by MCMC method, the proportion of asymptomatic infectors was 14.88% (IQR 8.17%, 25.37%). The association between air temperature and the fitted transmission rate (β) of COVID-19 suggests that COVID-19 pandemic would be seasonal with the optimal temperature range of 5℃-14℃ and peak of 10℃ for spreading, and vaccine is indispensable to ultimate prevention COVID-19.

1089: Prognostic Value of Molecular Staging of Bladder Cancer with RT -PCR Assay for KRT20: Results at 5 Year-Follow-up

2007 ◽  
Vol 177 (4S) ◽  
pp. 360-360
Author(s):  
Ana Agud ◽  
Maria J. Ribal ◽  
Lourdes Mengual ◽  
Mercedes Marin-Aguilera ◽  
Laura Izquierdo ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Prognostic Value ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Molecular Staging

Polymerase chain reaction amplification and typing of rotavirus in environmental samples

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch
Keyword(s):  
Polymerase Chain Reaction ◽  
Environmental Samples ◽  
Polymerase Chain Reaction Amplification ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Group A ◽  
Reaction Amplification ◽  
Stool Specimens ◽  
Polymerase Chain

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.

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