Reverse transcription-PCR Testing Research Articles

Comparative evaluation of RT-PCR and antigen-based rapid diagnostic tests (Ag-RDTs) for SARS-CoV-2 detection: performance, variant specificity, and clinical implications.

The COVID-19 pandemic has highlighted the critical need for accurate and efficient diagnostic tools for detecting severe acute respiratory coronavirus 2 (SARS-CoV-2) infections. This study presents a comparison of two diagnostic tests: RT-PCR and antigen detection rapid diagnostic tests (Ag-RDTs). This study focused on their performance, variant specificity, and their clinical implications. A simultaneous testing of 268 samples was carried out for SARS-CoV-2 using RT-PCR and Ag-RDTs [flourescence immunoassay (FIA) and lateral flow immunoassay (LFIA)]. Viral load was quantified, and variant identification was performed using a PCR-based assay. The prevalence was found to be 30.2% using reverse transcription PCR (RT-PCR), 26.5% using FIA, and 25% using LFIA. When comparing the FIA and LFIA, the overall diagnostic performance was found to be 80.25% vs 76.54%, 96.79% vs 97.33%, 91.55% vs 90.51%, and 91.88% vs 92.56% for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), respectively. Both Ag-RDTs showed a strong agreement with RT-PCR (κ = 0.78-0.80). The overall accuracies of the FIA and LFIA were 92.41% and 92.13%, respectively. The FIA showed higher sensitivity (73.68%) and PPV (92.08%) than the LFIA (65.79% and 90.56%, respectively) in asymptomatic patients. At low Ct values (<25), both Ag-RDTs had 100% sensitivity, but the sensitivity reduced to 31.82% for FIA and 27.27% for LFIA at Ct values > 30. The diagnostic sensitivity of FIA compared to LFIA for detecting the Alpha variant was 78.85% vs. 69.23% and 72.22% vs. 83.33% for the Delta variant. Both Ag-RDTs had 100% sensitivity for detecting Omicron. Both Ag-RDTs performed well in patients with high viral loads and Omicron variant infections compared to those infected with Alpha and Delta variants. This study confirms the comparable performance of RT-PCR and Ag-RDTs, specifically FIA and LFIA, for SARS-CoV-2 detection. The FIA showed higher sensitivity and PPV in asymptomatic cases, while both Ag-RDTs exhibited strong agreement with RT-PCR results. Notably, Ag-RDTs, particularly FIA, proved effective in detecting the Omicron variant and cases with high viral loads, highlighting their potential clinical utility in managing the COVID-19 pandemic.IMPORTANCEThis study is of utmost importance in providing effective responses to manage the COVID-19 pandemic. It rigorously compares the diagnostic accuracy, variant specificity, and practical considerations of reverse transcription PCR (RT-PCR) and antigen detection rapid diagnostic tests (Ag-RDTs) for severe acute respiratory coronavirus 2 (SARS-CoV-2), answering critical questions. The results of this study will help healthcare professionals choose the appropriate testing methods, allocate resources effectively, and enhance public health strategies. Given the evolution of the virus, understanding the performance of these diagnostic tools is crucial to adapting to emerging variants. Additionally, the study provides insights into logistical challenges and accessibility issues, which will contribute to refining testing workflows, particularly in resource-limited settings. Ultimately, the study's impact extends to global healthcare, providing valuable information for policymakers, clinicians, and public health officials as they work together for mitigating the impact of the pandemic.

Does SARS-CoV-2 infection cause persistent ocular symptoms?: A cross-sectional study after the lifting of lockdown in Chongqing, China.

To confirm whether ocular symptoms and complaints related to the COVID-19 infection persist after recovery. A cross-sectional study was conducted on people who came to the healthcare center for regular physical examinations when the lockdown lifted for nearly 1 month. Ophthalmologists performed comprehensive ocular examinations. The infection history of COVID-19 was identified by a self-reported reverse transcription-PCR (RT-PCR) test of a nasopharyngeal swab sample for SARS-CoV-2 or a novel coronavirus antigen test with self-reported typical infection symptoms. Demographic data was collected from their healthcare reports. Ocular history and ocular symptoms were collected through face-to-face interviewing. Of a total of 308 participants, 264 (85.7%) reported COVID-19 infection; 73 (27.65%) of infected persons complained of various ocular symptoms during or after infection; and only 15 (5.68%) persons reported ocular symptoms after recovery. Infection significantly increased the complaints of red eye and eye pain compared to the time before knockdown. There were no significant differences between infections and noninfectious infections in various ocular examinations at the time of examination. The duration between the day of infection onset and examination day was unrelated to all ocular examinations. COVID-19 infection can lead to some ocular symptoms, especially conjunctival congestion and ocular pain in the infective stage, but may not cause persistent ocular symptoms in about 1 month after recovery. The results of this study may help relieve public concerns about coronavirus infection in the eyes. However, more studies on various coronavirus infections, with large sample sizes, are warranted in multi-center and community-based populations.

Performance Evaluation of Rapid Antigen Test for COVID-19 with SARS-CoV-2 RT-PCR using Nasopharyngeal Swab with Special Reference to RNA Dependent RNA Polymerase (RdRp) Cycle Threshold Values

SARS-CoV-2 is highly contagious, which spreads even by patients having no clinical symptoms or also from people suffering with only mild symptoms. The gold standard test for its diagnosis is reverse-transcription PCR (RT-PCR) but at times of pandemic, Rapid antigen tests (RAT) are required, which has a very less turn-around time. Evaluation of the performance of COVID-19 Rapid antigen test in comparison to SARS-CoV-2 RT-PCR using nasopharyngeal swab, in relation to RNA dependent RNA polymerase (RdRp) Cycle threshold (Ct) values. This observational and cross-sectional study was done on patients coming with features of Influenza-like illness (ILI) or for any aerosol generating procedure or on high-risk patients seeking hospitalization. Both RT-PCR and RAT for COVID-19 were done on samples collected from each patient and results were compared. Altogether, 5314 samples were tested, out of which 104 (01.95 %) &amp; 229 (04.31 %) samples were found positive by the RAT &amp; RT PCR test, respectively. Sensitivity, specificity, PPV and NPV of RAT were found to be 44.54%, 99.96%, 98.08% and 97.56%, respectively. 98.9 % of samples with Ct value ≤ 20 were positive by RAT, whereas only 2.2% samples having Ct value ≥ 26 were found to be positive. Cases having lower Ct values were found to be more symptomatic and vice-versa. RAT are not efficient in detecting the virus in samples showing high Ct values (Ct ≥ 26) by RT-PCR test. Patients with samples showing low Ct values (Ct ≤ 20) had more severe symptoms and vice-versa.

Lessons learnt from the first wave of COVID-19 in Damascus, Syria: a multicentre retrospective cohort study

ObjectivesThe decade-long Syrian war led to fragile health infrastructures lacking in personal and physical resources. The public health of the Syrian population was, therefore, vulnerable to the COVID-19 pandemic, which...

Effectiveness of inactivated COVID-19 vaccines against SARS-CoV-2 infections among healthcare personnel in Pakistan: a test-negative case–control study

ObjectiveDuring the COVID-19 pandemic, several vaccines that were efficacious in randomised controlled trials were authorised for mass vaccination. In developing countries, inactivated vaccines were widely administered. While inactivated vaccines have...

COVID-19 mortality among selective serotonin reuptake inhibitor users—results from a nationwide cohort

ObjectiveTo examine differences in mortality and/or severe acute respiratory syndrome between selective serotonin reuptake inhibitor- (SSRI) users and non-SSRI users up to 60 days after a positive SARS-CoV-2 real-time reverse transcription PCR test. MethodsRetrospective cohort study including all Danish residents above the age of eighteen with a positive SARS-CoV-2 PCR test from 26 February, 2020 to 5 October, 2021. The follow-up period was 60 days. The primary outcome was all-cause mortality, and the secondary outcome was severe acute respiratory syndrome. Exposure of interest was SSRI use. Differences between SSRI users and non-users were examined with Cox regression. ResultsAltogether, 286,447 SARS-CoV-2 positive individuals were identified, and 7113 met the criteria for SSRI use. SSRI users had a mean age of 50.4 years, and 34% were males. Non-SSRI users had a mean age of 41.4 years, and 50% were males. Similar vaccination frequency was observed among the two groups. Sertraline was the most commonly used SSRI, followed by citalopram and escitalopram. We found 255 deaths among SSRI users (3.6%) and 2872 deaths among non-SSRI users (1.0%). SSRI use was significantly associated with increased mortality, with a hazard ratio of 1.32 (95% confidence interval, 1.16 –1.50; p 0.015), even when adjusting for age, sex, vaccination status, and comorbidities. DiscussionWe found significantly higher mortality when comparing SSRI users to non-SSRI users within 60 days after a positive SARS-CoV-2 PCR test. Even when considering possible residual confounding, a positive effect of SSRI intake seems highly unlikely. Our study therefore speaks against the hypothesis of repurposing SSRI drugs for COVID-19 treatment.

SARS-CoV-2 incubation period across variants of concern, individual factors, and circumstances of infection in France: a case series analysis from the ComCor study

The incubation period of SARS-CoV-2 has been estimated for the known variants of concern. However, differences in study designs and settings make comparing variants difficult. We aimed to estimate the incubation period for each variant of concern compared with the historical strain within a unique and large study to identify individual factors and circumstances associated with its duration. In this case series analysis, we included participants (aged ≥18 years) of the ComCor case-control study in France who had a SARS-CoV-2 diagnosis between Oct 27, 2020, and Feb 4, 2022. Eligible participants were those who had the historical strain or a variant of concern during a single encounter with a known index case who was symptomatic and for whom the incubation period could be established, those who reported doing a reverse-transcription-PCR (RT-PCR) test, and those who were symptomatic by study completion. Sociodemographic and clinical characteristics, exposure information, circumstances of infection, and COVID-19 vaccination details were obtained via an online questionnaire, and variants were established through variant typing after RT-PCR testing or by matching the time that a positive test was reported with the predominance of a specific variant. We used multivariable linear regression to identify factors associated with the duration of the incubation period (defined as the number of days from contact with the index case to symptom onset). 20 413 participants were eligible for inclusion in this study. Mean incubation period varied across variants: 4·96 days (95% CI 4·90-5·02) for alpha (B.1.1.7), 5·18 days (4·93-5·43) for beta (B.1.351) and gamma (P.1), 4·43 days (4·36-4·49) for delta (B.1.617.2), and 3·61 days (3·55-3·68) for omicron (B.1.1.529) compared with 4·61 days (4·56-4·66) for the historical strain. Participants with omicron had a shorter incubation period than participants with the historical strain (-0·9 days, 95% CI -1·0 to -0·7). The incubation period increased with age (participants aged ≥70 years had an incubation period 0·4 days [0·2 to 0·6] longer than participants aged 18-29 years), in female participants (by 0·1 days, 0·0 to 0·2), and in those who wore a mask during contact with the index case (by 0·2 days, 0·1 to 0·4), and was reduced in those for whom the index case was symptomatic (-0·1 days, -0·2 to -0·1). These data were robust to sensitivity analyses correcting for an over-reporting of incubation periods of 7 days. SARS-CoV-2 incubation period is notably reduced in omicron cases compared with all other variants of concern, in young people, after transmission from a symptomatic index case, after transmission to a maskless secondary case, and (to a lesser extent) in men. These findings can inform future COVID-19 contact-tracing strategies and modelling. Institut Pasteur, the French National Agency for AIDS Research-Emerging Infectious Diseases, Fondation de France, the INCEPTION project, and the Integrative Biology of Emerging Infectious Diseases project.

Regional Evaluation of Two SARS-CoV-2 Antigen Rapid Diagnostic Tests in East Africa.

The clinical performance of two rapid antigen tests for the diagnosis of Severe Acute Respiratory Coronavirus (SARS-CoV-2) were regionally evaluated in East African populations. Swabs were collected from 1,432 individuals from five Partner States of the East African Community (Tanzania, Uganda, Burundi, Rwanda and South Sudan). The two rapid antigen tests (Bionote NowCheck COVID-19 Ag and SD Biosensor STANDARD Q COVID-19 Ag) were evaluated against the detection of SARS-CoV-2 RNA by the Reverse Transcription PCR (RT-PCR) gold standard. Of the concordant results with both RT-PCR and rapid antigen test data (862 for Bionote and 852 for SD Biosensor), overall clinical sensitivity was 60% and 50% for the Bionote NowCheck and the SD Biosensor STANDARD Q, respectively. Stratification by viral load, including samples with RT-PCR cycle thresholds (Ct) of <25, improved sensitivity to 90% for both rapid diagnostic tests (RDTs). Overall specificity was good at 99% for both antigen tests. Taken together, the clinical performance of both Ag-RDTs in real world settings within the East African target population was lower than has been reported elsewhere and below the acceptable levels for sensitivity of >80%, as defined by the WHO. Therefore, the rapid antigen test alone should not be used for diagnosis but could be used as part of an algorithm to identify potentially infectious individuals with high viral load. IMPORTANCE Accurate diagnostic tests are essential to both support the management and containment of outbreaks, as well as inform appropriate patient care. In the case of the SARS-CoV-2 pandemic, antigen Rapid Diagnostic Tests (Ag-RDTs) played a major role in this function, enabling widespread testing by untrained individuals, both at home and within health facilities. In East Africa, a number of SARS-CoV-2 Ag-RDTs are available; however, there remains little information on their true test performance within the region, in the hands of the health workers routinely carrying out SARS-CoV-2 diagnostics. This study contributes test performance data for two commonly used SARS-CoV-2 Ag-RDTs in East Africa, which will help inform the use of these RDTs within the region.

Causes of fetal death in the Flemish cattle herd in Brazil.

Flemish cattle in Brazil are on the brink of extinction and are found only in one herd in Lages, Santa Catarina State. This study aimed to uncover the reasons for the recurring abortions in the Flemish cattle herd. Seventeen Flemish fetuses underwent postmortem examinations, with samples collected for histopathology and microbiology culture tests, polymerase chain reaction (PCR) test for Neospora caninum, and reverse transcription-PCR (RT-PCR) test for bovine viral diarrhea virus (BVDV) from 2015 to 2020. Of the 17 fetuses, N. caninum was the most common diagnosis and was found in 88% (15/17). One fetus (5.8%) had a coinfection with N. caninum and Citrobacter amalonaticus, leading to fibrinonecrotic pericarditis. All fetuses tested negative for BVDV by RT-PCR. Of the 107 dams tested by indirect immunofluorescence assay, 26 (25.2%) were anti-N. caninum seropositive, with 17 (65.4%) aborting and 5 (19.2%) having estrus repetition. Reverse transcription-PCR results showed that 9 (8.4%) of the serum samples collected from dams tested positive, which tested follow-up test 3 months later, indicating a BVDV transient infection. The factors that contributed to neosporosis included dogs' access to pastures and improper disposal of fetal remains, which made it easier for dogs to consume them. This study warns the occurrence of N. caninum as a cause of reproductive disorders that can lead to abortion in the studied Flemish cattle herd.

A Novel, Divergent Member of the Rhabdoviridae Family Infects Strawberry.

Strawberry (Fragaria × ananassa) is the most important berry crop worldwide and viruses pose a constant threat to the industry. In this communication, we describe a novel virus in the family Rhabdoviridae referred to as strawberry virus 3 (StrV-3). The virus does not show significant homology when compared with recognized rhabdoviruses and, therefore, the establishment of a new genus should be considered. A triplex reverse-transcription PCR test was developed and successfully employed in a survey of the National Clonal Germplasm Repository Fragaria collection. A CRISPR-Cas-based protocol was also developed and shown to detect the virus in as little as 1 fg of total RNA, a protocol to be used in the detection of the virus in candidate G1 plants. The strawberry aphid (Chaetosiphon fragaefolii) was evaluated-alas, unsuccessfully-as a potential vector of the virus. This work broadens our understanding of the family Rhabdoviridae and assists in the quest of releasing plant material free of viruses.

A fast RT-qPCR system significantly shortens the time for SARS-CoV-2 nucleic acid test.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to global development. Rapid and accurate diagnosis is critical for containing the pandemic and treating patients in time. As the gold standard for SARS-CoV-2 diagnosis, the qualitative reverse transcription-PCR (RT-qPCR) test has long been criticized for its long detection time. In this study, we optimized the primers and probes targeting SARS-CoV-2 ORF1ab and N gene designed by the Chinese Center for Disease Control and Preventions (CDC) to increase their Tm values to meet the optimal elongation temperature of Taq DNA polymerase, thus greatly shortened the elongation time. The higher elongation temperature in turn narrowed the temperature range of the reaction and saved more time. In addition, by shortening the distance between the fluorophore at the 5' end and the quencher in the middle we got a probe with higher signal-to-noise ratio. Finally, by using all these measures and optimized RT-qPCR program we successfully reduced the time (nucleic acid extraction step is not included) for nucleic acid test from 74 min to 26 min.

Performance of three screening tools to predict COVID-19 positivity in emergency department patients

BackgroundCOVID-19 symptoms vary widely. This retrospective study assessed which of three clinical screening tools—a nursing triage screen (NTS), an ED review of systems (ROS) performed by physicians and physician assistants...

PM 7/31 (2) Citrus tristeza virus

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Most Current Microbial Terror to Humanity - A Review

Current, on-going microbial terror to humanity needs public enlightenment. Unknown to most people, it is the18th such terror in recorded human history. First noticed in Wuhan (China) in early December 2019 as atypical pneumonia reported in a cluster of patients, and later discovered to be caused by a new coronavirus, called SARS-CoV-2, best known by WHO’s terminology, COVID-19. Routes of transmission are droplets, aerosols and fomites, close face-to-face contacts, and spread by asymptomatic, pre-symptomatic and symptomatic carriers. Symptoms and signs are typically an influenza-like syndrome: rigours, fatigue, high-fever, dry-cough, shortness of breath, fatigue, myalgia, headache, weakness, less commonly, nausea, vomiting, and diarrhea. Complications include pneumonia, acute respiratory disease syndromes necessitating supplemental oxygen, acute liver, kidney, and cardiac injuries, that necessitates intensive-care units. Diagnosis is by detection of SARS-CoV-2 via reverse transcription PCR testing. Clinical management involves providing supportive care to relief aforementioned symptoms, supporting vital organ functions, treating secondary bacterial infections, and managing critically ill-patients in ICUs. Socio-economic effects include forced restrictions, quarantine, testing, vaccination and travel bans; globally as of October 01, 2021: economy shrunk by 3.5 per cent, with monumental financial loss of over $21, 000,000,000,000; world total infected individuals = 234,707,794; confirmed death = 4,800,466; recovered cases = 211,514,975; day new cases = 146, 944; day new deaths = +3,036. USA, India, Brazil, UK. Russia, Turkey and France topped the list of casualties in that order; Nigeria is 98th in the list; daily details obtainable from: www.worldometers.info/coronavirus.. Succor is that about 270 vaccines are presently in production; six are in use.

Assessing the Pre-Vaccination Anti-SARS-CoV-2 IgG Seroprevalence among Residents and Staff in Nursing Home in Niigata, Japan, November 2020.

An outbreak of coronavirus disease 2019 (COVID-19) occurred in a nursing home in Niigata, Japan, November 2020, with an attack rate of 32.0% (63/197). The present study was aimed at assessing the pre-vaccination seroprevalence almost half a year after the COVID-19 outbreak in residents and staff in the facility, along with an assessment of the performance of the enzyme-linked immunosorbent assay (ELISA) and the chemiluminescent immunoassay (CLIA), regarding test seropositivity and seronegativity in detecting immunoglobulin G (IgG) anti-severe acute respiratory syndrome 2 (SARS-CoV-2) antibodies (anti-nucleocapsid (N) and spike (S) proteins). A total of 101 people (30 reverse transcription PCR (RT-PCR)-positive and 71 RT-PCR-negative at the time of the outbreak in November 2020) were tested for anti-IgG antibody titers in April 2021, and the seroprevalence was approximately 40.0-60.0% for residents and 10.0-20.0% for staff, which was almost consistent with the RT-PCR test results that were implemented during the outbreak. The seropositivity for anti-S antibodies showed 90.0% and was almost identical to the RT-PCR positives even after approximately six months of infections, suggesting that the anti-S antibody titer test is reliable for a close assessment of the infection history. Meanwhile, seropositivity for anti-N antibodies was relatively low, at 66.7%. There was one staff member and one resident that were RT-PCR-negative but seropositive for both anti-S and anti-N antibody, indicating overlooked infections despite periodical RT-PCR testing at the time of the outbreak. Our study indicated the impact of transmission of SARS-CoV-2 in a vulnerable elderly nursing home in the pre-vaccination period and the value of a serological study to supplement RT-PCR results retrospectively.

Community-Based Surveillance and Geographic Information System‒Linked Contact Tracing in COVID-19 Case Identification, Ghana, March‒June 2020.

In response to the COVID-19 pandemic, Ghana implemented various mitigation strategies. We describe use of geographic information system (GIS)‒linked contact tracing and increased community-based surveillance (CBS) to help control spread of COVID-19 in Ghana. GIS-linked contact tracing was conducted during March 31-June 16, 2020, in 43 urban districts across 6 regions, and 1-time reverse transcription PCR testing of all persons within a 2-km radius of a confirmed case was performed. CBS was intensified in 6 rural districts during the same period. We extracted and analyzed data from Surveillance Outbreak Response Management and Analysis System and CBS registers. A total of 3,202 COVID-19 cases reported through GIS-linked contact tracing were associated with a 4-fold increase in the weekly number of reported SARS-CoV-2 infected cases. CBS identified 5.1% (8/157) of confirmed cases in 6 districts assessed. Adaptation of new methods, such as GIS-linked contact tracing and intensified CBS, improved COVID-19 case detection in Ghana.

Effect of age on computed tomography findings: Specificity and sensitivity in coronavirus disease 2019 infection.

BACKGROUNDCoronavirus disease 2019 (COVID-19) is a pandemic caused by the severe acute respiratory syndrome coronavirus in 2019. Although the real-time reverse tr-anscription PCR test for viral nucleic acids is the gold standard for COVID-19 diagnosis, computed tomography (CT) has grown in importance.AIMTo evaluate the sensitivity and specificity of thoracic CT findings of COVID-19 pneumonia according to age groups.METHODSPCR and CT results from 411 patients were reviewed. The diagnosis of COVID-19 pneumonia was made by three radiologists. Lymphadenopathy, pericardial effusion, pleurisy, pleural thickening, pleural effusion, location features of the lesions, ground glass, consolidation, air bronchogram, vascular enlargement, bronchial dilatation, halo finding, inverted halo sign, nodularity, air bubble, subpleural band (curvilinear density), reticular density, crazy paving pattern, and fibrosis findings were recorded. The patients were divided into nine groups by decades while calculating the sensitivity, specificity, and diagnostic efficacy for CT positivity.RESULTSThe mean age of the cases was 48.1 ± 22.7 years. The CT finding with the highest diagnostic power was ground glass. Vascular enlargement and bronchial dilatation followed ground glass. Peri-cardial effusion was the finding with the lowest diagnostic accuracy. The incidence of lymphadenopathy, pleurisy, pleural thickening, peripheral localization, bilateral, ground glass, vascular enlargement, bronchial dilatation, subpleural band, reticular density, crazy paving appearance, and fibrosis all increased increase significantly with age in patients with positive real-time reverse transcription PCR test.CONCLUSIONThere are few publications comparing sensitivity and specificity of thoracic CT findings according to age. In cases of COVID-19 pneumonia, there is an increase in the variety and frequency of CT findings with age, and parallel to this the sensitivity and specificity of the findings increase. COVID-19 cases in the pediatric age group have fewer lung findings than adults, and this situation decreases the diagnostic value of CT in pediatric patients.

Post-acute COVID and long-COVID among adults and older adults in the State of Paraná, Brazil: protocol for an ambispective cohort study

IntroductionSince 2020, the world has been going through a viral pandemic with a high morbidity and mortality rate along with the potential to evolve from an acute infection to post-acute...

FIFA Arab Cup tournament with full capacity of spectators during the COVID-19 pandemic: a cross-sectional study

ABSTRACT Background We sought to assess the risk of COVID-19 and seasonal flu including respiratory syncytial (RSV) and influenza viruses during the FIFA Arab Cup 2021 in Qatar with full capacity of spectators. We also, evaluated the post-event attitude toward resumption of mass football events. Methods This was a cross-sectional study in which spectators (age ≥ 18 years) were invited for reverse-transcription PCR testing for COVID-19 and seasonal flu. At the same time, between 7 and 14 days after the event, the participants completed a self-administered questionnaire regarding their concerns during the tournament. Results The tournament included 16 international football teams from the Arab countries. As per the study protocol, 10,000 spectators were approached and 6,475 participated. Among the participants, 4,195 (65.1%), 2,253 (34.9%) and 27 (0.4%) were vaccinated with 2 doses, vaccinated with 3 doses, and recovered from SARS-Cov-2 infection, respectively. There were 61 (0.9%), 41(0.6%) and 11(0.2%) participants who tested positive for COVID-19, RSV and influenza (A/B), respectively. The average cycle threshold (Ct) value for COVID-19 positive cases was 26.1±7.3. Among those who were electronically approached, 6,102 completed the survey whereas 373 had incomplete survey. Overall, 2069 (33.9%) participants reported symptoms that theoretically could be related to COVID-19, of them 39 had positive PCR test (1.9%). Spectators (94.3%) were optimistic about returning sport events to the pre-pandemic status. Conclusions There was no significant increase in the daily COVID-19 cases during FIFA Arab Cup 2021 with a full capacity of spectators. Therefore, upcoming mass football events can be held safely.

Incidentally Detected PET-CT Imaging Findings Of COVID-19 Pneumonia: A Retrospective Study During Local Pandemic Era

Background: COVID-19 has been declared a global health emergency by the World Health Organisation (WHO). Commonly, a CT chest scan is performed to detect any early findings of COVID-19 pneumonia before the onset of clinical symptoms. In this article, the authors reported COVID-19 pneumonia in patients undergoing positron emission tomography with 2-deoxy-2-(fluorine-18) fluoro-D-glucose integrated with CT (18F-FDG PET/CT) examinations for early isolation and necessary management. Methods: One hundred and twelve patients who underwent 18F-FDG PET/CT imaging for routine oncological examination were considered for the study, and these subject scans were taken during a period of December 2020–August 2021. Following which, reverse transcription-PCR testing was requested for confirmation. Results: Amongst the 112 patients, 45 (40%) patients showed features of COVID-19 pneumonia on PET/CT imaging. Reverse transcription-PCR testing carried out for these patients confirmed the infection in 38 individuals (84%). Conclusion: 18F-FDG PET/CT is sensitive for early detection of COVID-19 pneumonia, so as to minimise further spread of infection and apply adequate measures for prevention.