Positive Reverse Transcription-polymerase Chain Reaction Research Articles

Can lung anatomy predict the development of COVID-19 pneumonia in RT-PCR positive cases?

Purpose: The objective of this study was to investigate the relationship between Coronavirus disease 2019 (COVID-19) pneumonia and anatomical characteristics, including tracheobronchial and fissure variations, right/left main bronchus angle, carina angle, and large airway diameter, in patients who tested positive for the virus via reverse transcription-polymerase chain reaction (RT-PCR) at the outset of the pandemic. Materials and Methods: This cross-sectional study included 165 cases with positive RT-PCR tests who were admitted between March and June 2020 and subsequently scanned with thin-section unenhanced chest computed tomography (CT). They were divided into two groups according to the presence of pneumonia based on the chest CT images. Results: In our study, a total of 165 cases were analyzed, pneumonia was found in 35 of 76 (46.05%) female patients and 51 of 89 (57.30%) male patients. COVID-19 pneumonia was observed in older age groups. Anatomical variations and the presence of incomplete fissures were statistically higher in the pneumonia-positive group, while the difference was not statistically significant for accessory fissures. Mean tracheal area and right main bronchus angle were statistically higher in the pneumonia-positive group compared to the negative patients. The right lung was more involved than the left in terms of both zonal and total lung involvement. When the presence of comorbidity was assessed, 59 patients (35.75%) were found to have comorbidity. Hypertension, diabetes mellitus and cardiovascular disease were significantly higher among comorbidities in the pneumonia-positive group. The regression model showed that hypertension was associated with a 3.75-fold increase in COVID-19 pneumonia in test positive cases. Conclusion: Anatomical lung variations and incomplete fissures were observed more frequently in the COVID-19 pneumonia cases, independent of other comorbidities. We believe that there are anatomical variables that can be used to identify those predisposed to pneumonia in RT-PCR test positive cases.

Portal Vein Thrombosis in COVID-19: An Underdiagnosed Disease?

Background: Multiple studies have linked COVID-19 to a higher incidence of thromboembolic disorders. However, the association of COVID-19 with other potentially life-threatening complications, such as splanchnic vein thrombosis, is less well understood. This study aims to assess the prevalence, patient characteristics, clinical presentation, and outcomes of patients with portal vein thrombosis (PVT) and COVID-19. Methods: This was a retrospective observational study. From all positive patients for a reverse-transcription polymerase chain reaction (RT-PCR) swab test from March 2020 to June 2020, we included those who were older than 18 years, had received abdominal contrast-enhanced computed tomography (CT) in the 6 months following the positive RT-PCR swab, and had no previously known splanchnic vein thrombosis. Results: A total of 60 patients with abdominal CT were selected from all those positive for SARS-CoV-2 (n = 2987). The prevalence of PVT was 3/60 (5%). The mean age was 66.1 ± 16.5 years and 51.7% were male. In two of the three patients, there was no underlying pathology as a risk factor for PVT and one of them presented cirrhosis. The number of days from the start of COVID-19 symptoms until the PVT diagnosis were 21, 12, and 10 days. Anticoagulation treatment achieved recanalization in 100% of cases. During a mean follow-up of 803 days, none of the patients experienced long-term complications. Conclusions: Portal vein thrombosis is uncommon, and its incidence may be higher in COVID-19 patients. A greater understanding of the features of this disease in the context of COVID-19 could aid towards its diagnosis and allow for early detection and management.

SARS-CoV-2 Seropositivity in Nursing Home Staff and Residents during the First SARS-CoV-2 Wave in Flanders, Belgium.

(1) Background: early in the COVID-19 pandemic, reverse transcription polymerase chain reaction (RT-PCR) testing was limited. Assessing seroprevalence helps understand prevalence and reinfection risk. However, such data are lacking for the first epidemic wave in Belgian nursing homes. Therefore, we assessed SARS-CoV-2 seroprevalence and cumulative RT-PCR positivity in Belgian nursing homes and evaluated reinfection risk. (2) Methods: we performed a cross-sectional study in nine nursing homes in April and May 2020. Odds ratios (ORs) were calculated to compare the odds of (re)infection between seropositive and seronegative participants. (3) Results: seroprevalence was 21% (95% CI: 18-23): 22% (95% CI: 18-25) in residents and 20% (95% CI: 17-24) in staff. By 20 May 2020, cumulative RT-PCR positivity was 16% (95% CI: 13-21) in residents and 8% (95% CI: 6-12) in staff. ORs for (re)infection in seropositive (compared to seronegative) residents and staff were 0.22 (95% CI: 0.06-0.72) and 3.15 (95% CI: 1.56-6.63), respectively. (4) Conclusion: during the first wave, RT-PCR test programmes underestimated the number of COVID-19 cases. The reinfection rate in residents was 3%, indicating protection, while it was 21% in staff, potentially due to less cautious health behaviour. Future outbreaks should use both RT-PCR and serological testing for complementary insights into transmission dynamics.

SARS-CoV-2 Variants May Affect Saliva RT-PCR Assay Sensitivity.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants demonstrate predilection for different regions of the respiratory tract. While saliva-based reverse transcription-polymerase chain reaction (RT-PCR) testing is a convenient, cost-effective alternative to nasopharyngeal swabs (NPS), few studies to date have investigated whether saliva sensitivity differs across variants of concern. SARS-CoV-2 RT-PCR was performed on paired NPS and saliva specimens collected from individuals with acute coronavirus disease 2019 (COVID-19) symptoms or exposure to a COVID-19 household contact. Viral genome sequencing of NPS specimens and Los Angeles County surveillance data were used to determine the variant of infection. Saliva sensitivity was calculated using NPS-positive RT-PCR as the reference standard. Factors contributing to the likelihood of saliva SARS-CoV-2 RT-PCR positivity were evaluated with univariate and multivariable analyses. Between June 2020 and December 2022, 548 saliva samples paired with SARS-CoV-2 positive NPS samples were tested by RT-PCR. Overall, saliva sensitivity for SARS-CoV-2 detection was 61.7% (95% CI, 57.6%-65.7%). Sensitivity was highest with Delta infection (79.6%) compared to pre-Delta (58.5%) and Omicron (61.5%) (P = 0.003 and 0.01, respectively). Saliva sensitivity was higher in symptomatic individuals across all variants compared to asymptomatic cases [pre-Delta 80.6% vs 48.3% (P < 0.001), Delta 100% vs 72.5% (P = 0.03), Omicron 78.7% vs 51.2% (P < 0.001)]. Infection with Delta, symptoms, and high NPS viral load were independently associated with 2.99-, 3.45-, and 4.0-fold higher odds of SARS-CoV-2 detection by saliva-based RT-PCR (P = 0.004, <0.001, and <0.001), respectively. As new variants emerge, evaluating saliva-based testing approaches may be crucial to ensure effective virus detection.

Examination of SARS-CoV-2 RNA in joint synovial fluid of patients with COVID-19 and acute knee arthritis.

It has not yet been fully established that there is coronavirus disease 2019 (COVID-19) involvement in the synovial fluid and it remains a topic of debate. The aim of this study was to evaluate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in knee joint synovial fluid of patients with COVID-19. This retrospective study was conducted with an initial screening of patients who were admitted to a tertiary pandemic hospital due to COVID-19 symptoms, and underwent treatment for COVID-19 between March and June 2020. A total of 2476 patients were hospitalized or received treatment for a possible diagnosis of COVID-19. While the RT-PCR test was positive in 318 patients (12.8%), 2158 (87.2%) were computed tomography positive but reverse transcription-polymerase chain reaction (RT-PCR) negative. Twelve patients were consulted due to acute joint effusion. Of five patients with knee joint effusion and a positive RT-PCR test, the synovial tissue RT-PCR test was positive in only one patient. This paper is the first to show the presence of SARS-CoV-2 in synovial fluid. This can be considered of importance for the determination and elimination of the route of transmission, thereby preventing further development and spread of the disease.

Detection of COVID-19 incidence among attendees of the 2022 Hajj season

ObjectivesThis study investigated the presence of COVID-19 cases among pilgrims, health care workers (HCWs), and non-HCWs of Hajj 2022. MethodsNasopharyngeal samples were collected from 491 attendees of Hajj 2022. All participants received three doses of COVID-19 vaccines. Paired (n = 138; 69 participants) and unpaired (n = 422; 422 participants) nasopharyngeal swabs were subjected to reverse transcription–polymerase chain reaction targeting E gene of β-coronaviruses and RNA-dependent RNA polymerase of SARS-CoV-2. The results were linked to the participants’ profiles, including role during Hajj, presence of respiratory symptoms or comorbidities, contact with symptomatic individuals, smoking status, and COVID-19 recovery. ResultsA total of 20 (20 of 560; 3.6%) samples tested positive for COVID-19. Most cases (18 of 20; 90%) were pilgrims and non-HCWs. Six (30%) samples belonged to participants with previous positive reverse transcription–polymerase chain reaction. A total of 12 (60%) samples belonged to participants with respiratory symptoms. Three (15%) cases were linked to participants who had contact with individuals with respiratory symptoms. All cases belonged to individuals with no comorbidities, apart from a single case who has a chronic sinusitis. Five (25%) cases were smokers. No significant association was found between positive COVID-19 test and participants’ profiles. ConclusionsFew COVID-19 cases were detected in this study. Sustainable surveillance of COVID-19 and other respiratory viruses during Hajj seasons remains necessary.

Donor-derived dengue infections - A review of screening protocol and outcomes in an endemic country.

Donor-derived dengue infections present significant challenges to organ transplantation, particularly in endemic regions like Singapore. Although primarily transmitted by Aedes mosquitoes, dengue can also be transmitted through organ transplantation, occasionally with fatal outcomes. This study aims to evaluate the outcomes and evolution of dengue screening protocols for potential deceased donors in Singapore from 2006 to 2022. Initially, screening was done via dengue immunoglobulin M (IgM), targeting donors with specific clinical criteria (thrombocytopenia, drop in platelet count, prolonged prothrombin time/partial thromboplastin time, and discretion of the transplant team), later transitioning to blood dengue reverse transcription-polymerase chain reaction (RT-PCR) in 2007 with similar criteria, and subsequently universal screening in 2016. In 2021, urine dengue RT-PCR was added following a case of donor-derived dengue infection from an aviremic but viruric donor. Out of 431 potential deceased donors, 395 (91.6%) underwent dengue screening, with six (1.5%) testing positive for dengue. In 2006, three positive screens were identified: two through dengue IgM and one via blood dengue RT-PCR; subsequent years saw one positive screen each in 2007, 2008, and 2019 via blood dengue RT-PCR. Potential deceased donors with a positive blood dengue screen were rejected as solid organ and tissue donors. Those with negative blood dengue RT-PCR but positive urine dengue RT-PCR would be rejected as kidney donors, but the use of other organs and tissues was at the discretion of the transplantation team. The optimal screening protocol remains uncertain, but our findings suggest that a universal screening strategy utilizing both blood and urine dengue RT-PCR could be considered in dengue-endemic countries.

Rhinovirus characteristics associated with viremia in childhood asthma.

Although rhinoviruses play a major role in exacerbations of childhood asthma, the presence of rhinovirus (RV) RNA in plasma, referred to as viremia, has been investigated in a few studies. The aim of the study was to investigate the presence of rhinovirus viremia at the time of asthma exacerbation and to describe the molecular characteristics of rhinoviruses associated with viremia. We conducted an observational, prospective, multicenter study in eight pediatric hospitals (VIRASTHMA2). Preschool-aged recurrent wheezers (1-5 years) hospitalized for a severe exacerbation were included. Reverse-transcription polymerase chain reaction (RT-PCR) and molecular typing for RV/enteroviruses (EV) were performed on nasal swabs and plasma. Plasma specimens were available for 105 children with positive RT-PCR for RV/EV in respiratory specimens. Thirty-six (34.3%) had positive viremia. In plasma, 28 (82.4%) of the typable specimens were RV-C, five (14.7%) were EV-D68, and one was RV-A (2.9%). In all cases, the RV/EV type was identical in the plasma and respiratory specimens. In conclusion, RV/EV viremia is frequent in severe exacerbations of preschool recurrent wheezers, particularly in RV-C infections.

Associations between COVID-19 and Glucose-6-Phosphate Dehydrogenase Activity in Brazil.

Glucose-6 phosphate dehydrogenase deficiency (G6PDd) was suggested as a risk factor for severe disease in patients with COVID-19. We evaluated clinical outcomes and glucose-6 phosphate dehydrogenase (G6PD) activity during and after illness in patients with COVID-19. This prospective cohort study included adult participants (≥18 years old) who had clinical and/or radiological COVID-19 findings or positive reverse transcription-polymerase chain reaction results. Epidemiological and clinical data were extracted from electronic medical records. Glucose-6 phosphate dehydrogenase activity was measured using SD Biosensor STANDARD G6PD® equipment on admission and 1 year after discharge. Samples were genotyped for the three most common single nucleotide polymorphisms for G6PDd in the Brazilian Amazon. Seven hundred fifty-three patients were included, of whom 123 (16.3%) were G6PD deficient. There was no difference between groups regarding the risks of hospitalization (P = 0.740) or invasive mechanical ventilation (P = 0.31), but the risk of death was greater in patients with normal G6PD levels (P = 0.022). Only 29 of 116 participants (25%) carried the African G6PDd genotype. Of 30 participants tested as G6PD deficient during disease, only 11 (36.7%) results agreed 1 year after discharge. In conclusion, this study does not demonstrate an association of G6PDd with severity of COVID-19. Limitations of the test for detecting enzyme levels during COVID-19 illness were demonstrated by genotyping and retesting after the disease period. Care must be taken when screening for G6PDd in patients with acute COVID-19.

SARS-CoV-2 Viral Shedding and Rapid Antigen Test Performance - Respiratory Virus Transmission Network, November 2022-May 2023.

As population immunity to SARS-CoV-2 evolves and new variants emerge, the role and accuracy of antigen tests remain active questions. To describe recent test performance, the detection of SARS-CoV-2 by antigen testing was compared with that by reverse transcription-polymerase chain reaction (RT-PCR) and viral culture testing during November 2022-May 2023. Participants who were enrolled in a household transmission study completed daily symptom diaries and collected two nasal swabs (tested for SARS-CoV-2 via RT-PCR, culture, and antigen tests) each day for 10 days after enrollment. Among participants with SARS-CoV-2 infection, the percentages of positive antigen, RT-PCR, and culture results were calculated each day from the onset of symptoms or, in asymptomatic persons, from the date of the first positive test result. Antigen test sensitivity was calculated using RT-PCR and viral culture as references. The peak percentage of positive antigen (59.0%) and RT-PCR (83.0%) results occurred 3 days after onset, and the peak percentage of positive culture results (52%) occurred 2 days after onset. The sensitivity of antigen tests was 47% (95% CI=44%-50%) and 80% (95% CI=76%-85%) using RT-PCR and culture, respectively, as references. Clinicians should be aware of the lower sensitivity of antigen testing compared with RT-PCR, which might lead to false-negative results. This finding has implications for timely initiation of SARS-CoV-2 antiviral treatment, when early diagnosis is essential; clinicians should consider RT-PCR for persons for whom antiviral treatment is recommended. Persons in the community who are at high risk for severe COVID-19 illness and eligible for antiviral treatment should seek testing from health care providers with the goal of obtaining a more sensitive diagnostic test than antigen tests (i.e., an RT-PCR test).

Fukuchi-Manabe Score for Infection Control Measures During the Very Early COVID-19 Pandemic Period When Access to Reverse Transcription-Polymerase Chain Reaction Testing Was Poor in Japan: A Single-Center Observational Prospective Cohort Study.

During the early stages of the COVID-19 pandemic in Japan, access to reverse transcription-polymerase chain reaction (RT-PCR) testing was limited. All patients with COVID-19 required hospitalization, and isolation of suspected COVID-19 patients had not yet been implemented. With the recently acquired evidence on COVID-19, it is important to develop a risk stratification system for isolation rooms in the context of limited resources for better resource management. This study aimed to develop and validate a COVID-19 risk-scoring strategy, the Fukuchi-Manabe score, to safely stratify and manage isolation rooms, personal protective equipment (PPE), and RT-PCR testing in the context of limited RT-PCR testing and a short supply of PPE. This single-center prospective study consecutively enrolled suspected COVID-19 adult inpatients between March 1 and August 31, 2020. The primary and secondary outcomes were a positive RT-PCR test and the occurrence of nosocomial infections during the study period, respectively. Factors related to patient history, symptoms, chest computed tomography findings, and laboratory data suggestive of COVID-19 were scored, totaled, and divided into four categories ("probable," "possible," "less likely," and "non-suspicious") based on the likelihood of COVID-19. Sensitivity, specificity, and positive and negative predictive values were evaluated for each probability category. Twenty of 224 inpatients were positive on the RT-PCR test, including 18 "probable" patients (90.0%), one "possible" patient, and one "less likely" patient. The area under the curve (AUC) (95% confidence interval: 0.841-0.977), sensitivity, and specificity were 0.909, 90.0%, and 80.4%, respectively. The positive and negative predictive values and accuracy for the "probable" category were 0.90, 0.80, and 0.82, respectively. The mean and standard deviation of AUCs, validated by bootstrap analysis, were 0.910±0.034. No nosocomial infections were observed. The Fukuchi-Manabe score will be helpful when other novel pathogens emerge in the future before the availability of genetic testing methods.

Estimating infection prevalence using the positive predictive value of self-administered rapid antigen diagnostic tests: An exploration of SARS-CoV-2 surveillance data in the Netherlands from May 2021 to April 2022.

Measuring the severity of the disease of SARS-CoV-2 is complicated by the lack of valid estimations for the prevalence of infection. Self-administered rapid antigen diagnostic tests (Ag-RDTs) were available in the Netherlands since March 2021, requiring confirmation by reverse-transcription polymerase chain reaction (RT-PCR) for positive results. We explored the possibility of utilizing the positive predictive value (PPV) of Ag-RDTs to estimate SARS-CoV-2 prevalence. We used data from all Public Health service testing facilities between 3 May 2021 and 10 April 2022. The PPV was calculated by dividing the number of positive RT-PCR results by the total number of confirmation tests performed, and used to estimate the prevalence and compared with the number of COVID-19 hospital admissions. In total 3,599,894 cases were included. The overall PPV was 91.8% and 88.8% were symptomatic. During our study period, the estimated prevalence ranged between 2-22% in symptomatic individuals and 2-14% in asymptomatic individuals, with a correlation between the estimated prevalence and hospital admissions two weeks later (r = 0.68 (p<0.01) and r = 0.60 (p<0.01) for symptomatic/asymptomatic individuals). The PPV of Ag-RDTs can help estimate changes in SARS-CoV-2 prevalence, especially when used in conjunction with other surveillance systems. However, the used method probably overestimated the true prevalence because of unmonitored differences in test propensity between individuals.

Evaluation of a New Standardized Nasal Sampling Method for Detection of SARS-CoV-2 RNA via RT-PCR.

The aim of this study was to compare the diagnostic accuracy of nasal sampling using a novel anterior nasal swab (ANS) (Rhinoswab) versus combined oro-nasopharyngeal (OP/NP) sampling in COVID-19 suspected patients. This prospective observational study was performed from 11 November to 2 December 2021 (part 1), and from 16 January to 22 February 2022 (part 2). Adult patients who attended the emergency room with suspected COVID-19 were asked to participate. One ANS and one OP/NP sample were consecutively collected, and both were analyzed via reverse transcription polymerase chain reaction (RT-PCR). The result of the OP/NP sample was considered to be the reference standard. A total of 412 patients were included, of whom 171 (41.5%) had a positive RT-PCR of the OP/NP swab, whereas 139 (33.7%) were positive on the ANS sample. The overall diagnostic accuracy for ANS sampling in terms of sensitivity, specificity, positive predictive value, and negative predictive value was 80.7% (95% CI 73.8-86.2), 99.6% (95% CI 97.3-100), 99.3% (95% CI 95.5-100), and 87.9% (95% CI 83.3-91.4), respectively. In conclusion, ANS sampling with the Rhinoswab identified 80.7% of all presented COVID-19 patients in an emergency department. Future studies should investigate if nasal Rhinoswab self-sampling is suitable for reliable diagnosis of COVID-19 in an outpatient setting.

A comparative study of diagnostic performance of COVID-19 Reporting and Data System and computed tomography severity score in clinically suspected COVID-19 patients

Purpose: The aim of this study was to compare the diagnostic performance of COVID-19 Reporting and Data System (CO-RADS) and computed tomography (CT) severity score (CT-SS) in patients with clinically suspected coronavirus disease. Methods: A cross-sectional study was done. Patients presenting to the emergency department with symptoms suspicious for COVID-19 were participated. Patients referred with a positive reverse transcription polymerase chain reaction (RT-PCR) had chest CT evaluation done by CO-RADS and CT-SS, respectively, by an independent investigator. A binomial logistic regression analysis was performed to calculate the sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the two scoring systems in diagnosing COVID infection, considering RT-PCR as the reference standard. Results: A total of 400 cases were evaluated. Two hundred sixty-eight patients with a clinical suspicion of COVID-19 had a positive RT-PCR. The mean duration of symptoms was 5.5 ± 3.4 (range, 1–21 days). The mean CO-RADS and CT-SS scores were 3.7 ± 1.4 (range, 1–5) and 9.1 ± 7.5 (range, 0–28), respectively. Air leaks, including pneumothorax, pneumomediastinum, and surgical emphysema, were observed in six cases. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of CO-RADS was 93.8, 80, 90.7, 92.1, and 90%, respectively. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of CT-SS were 95, 76, 86, 89, and 85%, respectively. The area under the curve (AUC) for CO-RADS was 0.943 [95% confidence interval (CI), 0.909–0.976, P &lt; 0.001] and AUC for CT-SS was 0.877 (95% CI, 0.821–0.933, P &lt; 0.001), respectively. The cut-off values of CT-SS and CO-RADS were 7.1 and 4.2, respectively. Conclusion: Both scoring systems had good sensitivity, specificity, and diagnostic accuracy in comparison to RT-PCR test to diagnose COVID-19 infection.

Influenza Vaccine Effectiveness against Hospitalization, Season 2021/22: A Test-Negative Design Study in Barcelona.

Vaccination is considered the most effective measure for preventing influenza and its complications. The influenza vaccine effectiveness (IVE) varies annually due to the evolution of influenza viruses and the update of vaccine composition. Assessing the IVE is crucial to facilitate decision making in public health policies. to estimate the IVE against hospitalization and its determinants in the 2021/22 season in a Spanish tertiary hospital. We conducted a prospective observational test-negative design study within the Development of Robust and Innovative Vaccine Effectiveness (DRIVE) project. Hospitalized patients with severe acute respiratory infection (SARI) and an available influenza reverse transcription polymerase chain reaction (RT-PCR) were selected and classified as cases (positive influenza RT-PCR) or controls (negative influenza RT-PCR). Vaccine information was obtained from electronic clinical records shared by public healthcare providers. Information about potential confounders was obtained from hospital clinical registries. The IVE was calculated by subtracting the ratio of the odds of vaccination in cases and controls from one, as a percentage (IVE = (1 - odds ratio (OR)) × 100). Multivariate IVE estimates were calculated using logistic regression. In total, 260 severe acute respiratory infections (SARI) were identified, of which 34 were positive for influenza, and all were subtype A(H3N2). Fifty-three percent were vaccinated. Adjusted IVE against hospitalization was 26.4% (95% CI -69% to 112%). IVE determinants could not be explored due to sample size limitations. Our data revealed non-significant moderate vaccine effectiveness against hospitalization for the 2021/2022 season.

Diagnostic accuracy of Panbio™ rapid antigen test for SARS-CoV-2 in paediatric population

BackgroundRapid antigen-detection tests (Ag-RDTs) are used to diagnose SARS-CoV-2 infection. Real-world studies of Ag-RDTs are necessary to evaluate their diagnostic yield in paediatric patients. Our aim was to evaluate the accuracy of the Panbio™ Rapid Antigen Test for SARS-CoV-2 in the setting of a primary health care centre (PHC), with use of the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) as gold standard.MethodsThis prospective diagnostic study was conducted at PHCs in Mallorca, Spain. Patients were ≤ 18 years-old that attended sites for RT-PCR testing due to symptoms suggestive of infection (fever, headache, nasal congestion and dry cough, among others) or epidemiological exposure (close contacts). Two samples were collected: a nasal mid-turbinate sample for Ag-RDTs and a nasopharyngeal swab for RT-PCR testing. The sensitivity, specificity, and predictive values of the AgRDT were calculated using the RT-PCR results as the reference.ResultsWe examined 1142 participants from 0 to 18 years (47.5% female, mean age 8.9 ± 4.8 years, median 9.0 [5.0–13.0]). There were 84 positive RT-PCR results (pre-test probability of 7.3%) and 52 positive Ag-RDT results. The sensitivity of the Ag-RDT was 59.5% (95% Confidence Interval (CI): 48.2–69.9%), the specificity was 99.8% (95%CI: 99.2–99.9%), the positive predictive value was 96.1% (95%CI: 85.6–99.4%), and the negative predictive value was 96.8% (95%CI: 95.6–97.7%). The sensitivity for individuals referred by a general practitioner (GP) or paediatrician due to symptoms was 71.4% (95%CI: 51.5–86.0%) and for asymptomatic individuals was 50.0% (95%CI: 9.1–90.8%). The specificity was greater than 98.9% overall and in all subgroups. The sensitivity was 73.0% (95%CI: 52.0–87.5%) for referred patients due to symptoms and who were tested within 5 days since symptom onset. No significant statistical differences between any groups were found. There were 34 false-negative Ag-RDT results (40.5%) and 2 false-positive Ag-RDT results (0.2%).ConclusionThe sensitivity of the Panbio™ Test in paediatric individuals is below the minimum of 80% recommended by the World Health Organization for Ag-RDTs. This test had better accuracy in individuals referred by a GP or paediatrician due to symptoms, rather than those who were asymptomatic or referred due to epidemiological exposure. The RT-PCR test using a nasopharyngeal swab is accurate, but a less invasive alternative that has better sensitivity than the Panbio™ Test is needed for paediatric populations.

Enhancing Olfactory Loss in COVID-19: The Impact of Body Position

Objective: To understand that COVID-19-induced hyposmia may fluctuate with spatial position. Introduction: COVID-19-induced hyposmia, exacerbated by supination, has yet to heretofore been described. Methods: Case Study: A 52-year-old right-handed woman was ansate until two years before presentation when she developed cold symptoms and sudden onset of loss of smell and taste, with a positive Reverse Transcription-Polymerase Chain Reaction test for COVID-19. Over three weeks, her smell and taste gradually returned to 85% of normal. She reported that her smell and taste would markedly worsen when she would lie down, to 30% of normal, but would improve with standing, moving, and sitting. Even reclining for a short nap would cause her sense of smell to drop, requiring her to stand for hours before her smell would recover, which caused her to fear sleeping and forced her to move around constantly. She markedly altered her lifestyle because of her fear of sleeping and assiduously avoided lying down: when so overwhelmed by tiredness that she must sleep, she would sleep sitting up. Results: Chemosensory Testing: Olfaction: Brief Smell Identification Test: 9 (normosmia). Alcohol Sniff Test: 3 (anosmia). Dirhinus amyl (pentyl) acetate Test: -7.0 (hyperosmia). Retronasal Olfaction: Retronasal Index: 8 (normosmia). Gustation: Phenylthiocarbamide Taste Test: 10 (normogeusia). Discussion: Despite cerebral autoregulation, recumbency may function to decrease venous return, altering calcium concentrations and hence olfactory ability. In the supine orientation, intrathoracic pressure increases, thus mimicking the Valsalva maneuver. This further increases intracranial pressure, decreases cerebral blood flow, and increases cerebral carbon dioxide. Perhaps this causes increased gamma-aminobutyric acid, an inhibitory neurotransmitter within the olfactory bulb, which reduces associated olfactory ability. Peradventure assuming the supine position induces general relaxation and stage. One sleep. Sleep reduces the intensity of perceptual experiences of all the senses, including the olfactory sense [1]. On the other hand, the supine and relaxed state may induce a positive effect. Based on Wolpe's reciprocal inhibition principle, such a relaxed effect causes fear inhibition, whereby there cannot be coexistent simultaneous opposite emotions [2]. Since fear has been demonstrated to improve olfactory ability, assuming the supine position induces relaxation and thus reduces fear-induced increased olfactory ability (Yakov, 2013; Keedwel, 2005). On the other hand, assuming the supine position may induce a kinesthetic distraction, changing the focus of attention away from chemosensation to a change in position. Lying in the lateral decubitus position possibly causes a modification in the olfactory cycle with greater engorgement in the inferiorly situated nostril, which may have a lesser olfactory ability [1]. In those with olfactory deficits after COVID-19 or other conditions, a reduced olfactory ability with lying down may have significant health risks. Further investigation into the impact of position on those with olfactory deficits from all sources, including COVID-19, is warranted.

Prolonged RT-PCR test positivity in hemodialysis patients with COVID-19

BackgroundThe weakened immune system of patients on hemodialysis (HD) may prolong SARS-CoV-2 infection compared to the general population. Current international guidelines recommend ending isolation in conjunction with serial testing in moderately and severely immunocompromised subjects. This study aimed to estimate SARS-CoV-2 infectivity by measuring RT-PCR test positivity in HD patients. A comparison between RT-PCR test and cycle threshold (Ct) value has been performed as a secondary endpoint.MethodsA single-center retrospective study was conducted at the University of Modena (Italy) from March 2020 to October 2022. Only patients on chronic HD therapy with COVID-19 were enrolled in the study. In our HD Center, two negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) results were used to end quarantine in this population. SARS-CoV-2 RT-PCR test positivity duration measured the time elapsed from a positive RT-PCR to a second negative test. Ct cut-off of 35 cycles was used to definite “high Ct value,” a condition characterized by a large number of cycles of PCR amplification to register a positive RT-PCR test.ResultsDuring the observational period, 159 cases of SARS-CoV-2 infections were diagnosed in 151 patients. Median age was 70.1 (54.3–81.6) years and males accounted for 59.6% of the COVID-19 population. Median duration of SARS-CoV-2 RT-PCR test positivity on the nasal mucosa accounted for 30 (IQR, 21–40.5) days. Unvaccinated patients experienced significantly longer RT-PCR test positivity compared to vaccinated patients (42 [IQR,31–56] vs. 28 [IQR,20–35.7] days; p = < 0.001). The use of high Ct value, a laboratory surrogate of SARS-CoV-2 replication, anticipated a negative RT-PCR test of 9 (IQR, 6–12) days. Multivariate linear regression analysis showed that increased age (β coefficient 0.31; confidence interval [CI] 95%, 0.14—0.43; p = < 0.001) and the lack of anti-SARS-CoV-2 vaccination (β 0.49 CI95%, 11.9–22.5; p = < 0.001) were predictors of a prolonged RT-PCR positivity.ConclusionsPatients with COVID-19 on HD had prolonged RT-PCR test positivity. The adoption of “high Ct value” criteria led to a significant reduction in the duration of RT-PCR test positivity compared to the use of the classical nucleic acid amplification test. In our study, the lack of SARS-CoV-2 vaccination and older age were independently associated with a longer RT-PCR positivity.

Healthcare use attributable to COVID-19: a propensity-matched national electronic health records cohort study of 249,390 people in Wales, UK

BackgroundTo determine the extent and nature of changes associated with COVID-19 infection in terms of healthcare utilisation, this study observed healthcare contact 1 to 4 and 5 to 24 weeks following a COVID-19 diagnosis compared to propensity-matched controls.MethodsTwo hundred forty nine thousand three hundred ninety Welsh individuals with a positive reverse transcription–polymerase chain reaction (RT-PCR) test were identified from data from national PCR test results. After elimination criteria, 98,600 positive individuals were matched to test negative and never tested controls using propensity matching. Cohorts were split on test location. Tests could be taken in either the hospital or community. Controls were those who had tested negative in their respective environments. Survival analysis was utilised for first clinical outcomes which are grouped into primary and secondary. Primary outcomes include post-viral-illness and fatigue as an indication of long-COVID. Secondary outcomes include clinical terminology concepts for embolism, respiratory conditions, mental health conditions, fit notes, or hospital attendance. Increased instantaneous risk for positive individuals was quantified using hazard ratios (HR) from Cox regression, while absolute risk (AR) and relative risk were quantified using life table analysis.ResultsAnalysis was conducted using all individuals and stratified by test location. Cases are compared to controls from the same test location. Fatigue (HR: 1.77, 95% CI: 1.34–2.25, p = < 0.001) and embolism (HR: 1.50, 95% CI: 1.15–1.97, p = 0.003) were more likely to occur in all positive individuals in the first 4 weeks; however, anxiety and depression (HR: 0.83, 95% CI: 0.73–0.95, p = 0.007) were less likely. Positive individuals continued to be more at risk of fatigue (HR: 1.47, 95% CI: 1.24–1.75, p = < 0.001) and embolism (HR: 1.51, 95% CI: 1.13–2.02, p = 0.005) after 4 weeks. All positive individuals are also at greater risk of post-viral illness (HR: 4.57, 95% CI: 1.77–11.80, p = 0.002). Despite statistical association between testing positive and several conditions, life table analysis shows that only a small minority of the study population were affected.ConclusionsCommunity COVID-19 disease is associated with increased risks of post-viral-illness, fatigue, embolism, and respiratory conditions. Despite elevated risks, the absolute healthcare burden is low. Subsequently, either very small proportions of people experience adverse outcomes following COVID-19 or they are not presenting to healthcare.

Maternal and Perinatal Outcomes of Pregnant Patients with Coronavirus Disease 2019: Data from a University Hospital Setting in Tirana, Albania, May 2020 to November 2021.

Scientific evidence suggests an increased risk of maternal and obstetric complications in pregnant patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study is aimed at evaluating perinatal and maternal outcomes among patients with coronavirus disease 2019 (COVID-19) in a university hospital setting. This was a prospective cohort study of 177 pregnant women with confirmed SARS-CoV-2 infection at a tertiary hospital between May 2020 and November 2021. Both symptomatic and asymptomatic women with a positive reverse transcription-polymerase chain reaction test result at any time during pregnancy were included in this study. For the purpose of this study, we classified COVID-19 cases into two groups: mild and severe cases. The two groups were then compared to predict how the clinical presentation of COVID-19 affected adverse maternal and perinatal outcomes. Gestational age ≥ 20 weeks at the time of infection was significantly associated with the occurrence of severe forms of the disease (relative risk (RR) 3.98, p = 0.01). Cesarean section was the preferred mode of delivery, with 95 women (62.1%) undergoing surgery. A total of 149 neonates were delivered to women who had confirmed SARS-CoV-2 infection at any time during the course of pregnancy of which thirty-five (23.5%) were admitted to the neonatal intensive care unit (NICU). Severe forms of COVID-19 increased the risk of premature delivery (RR 6.69, p < 0.001), emergency cesarean delivery (RR 9.4, p < 0.001), intensive care hospitalization (RR 51, p < 0.001), and maternal death (RR 12.3, p = 0.02). However, severe forms of SARS-CoV-2 infection are not directly responsible for low birth weight or the need for neonatal resuscitation. Our findings suggest that pregnant women presenting with severe COVID-19 disease are at an increased risk of adverse maternal and perinatal outcomes, such as premature delivery, cesarean section, admission to the ICU, and maternal death. Infection after the 20th week of gestation increases the risk of developing severe forms of the disease.