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Introduction and aims Viral hepatitis, which appears most frequently at birth or during childhood, is a disease whose transmission routes include tears, bile, sexual fluids, sweat, milk, urine, feces, and saliva. The aim of the present study was to analyze the specificity of the immunochromatographic and ELISA diagnostic tests for hepatitis B surface antigen and compare them with PCR testing. Materials and methods The study sample was made up of 140 men and 60 women referred to the Urmia Medical University hospital to undergo PCR testing for HBV diagnosis. The ELISA test was performed using the Pioneer Medicine Company kit (Tehran, Iran). Results The results of the HBs-Ag rapid test and the ELISA test were compared with the PCR test. The HBs-Ag rapid test had 97% sensitivity and 91% specificity, whereas the ELISA test had 78% sensitivity and 76% specificity. Discussion and conclusion According to our results, the immunochromatographic test was accurate for diagnosing HBs-Ag in blood and the ELISA test had acceptable sensitivity and specificity, compared with PCR testing.

Introduction: The objective of this study was to evaluate the clinical and laboratory outcomes of solid cancer patients who were reinfected with COVID-19. Methods: Patients who were tested negative on the Coronavirus disease 2019 (COVID-19) PCR test and those with improved clinical conditions after infection with COVID-19 were enrolled in this study. Patients who received a positive COVID-19 PCR test 28 days after the initial positive PCR test were considered as reinfected. Results: A total of 1024 patients with the diagnosis of solid malignancy and COVID-19 PCR positivity were examined. The reinfection rate was 3.1%. Mortality rate of reinfection was 34.3%. The serum ferritin and creatinine values in reinfection were found to be significantly higher than the first infection (respectively; p = 0.015, p = 0.014). Conclusion: This study has demonstrated one of the first preliminary clinical results of COVID-19 reinfection in solid cancer patients., Lay abstract Solid cancer patients are at a higher risk than general population in terms of Coronavirus disease 2019 (COVID-19) infectivity and COVID-19-associated death and disease. It is also known that COVID-19 infection has a more severe course in immunocompromised patients. Solid cancer patients may be a vulnerable subgroup of patients to reinfection with COVID-19. The rate of reinfection was 3.1% (n = 32) in our study population of 1024 solid cancer patients who were tested positive on a COVID-19 PCR test. The death rate of the patients with solid cancer was 34.3% (n = 11). In addition, we demonstrated that intensive care follow-up is significantly longer during the reinfection period. It was demonstrated that the time between the last dose of chemotherapy for the patients and the reinfection COVID PCR positivity did not affect the death rate. The COVID-19 pandemic has affected people's daily lives and treatments in many aspects. Owing to the high death rate of reinfection, even if cancer patients have reinfection, our approach is to continue cancer treatment as soon as the patient is cured. Finally, we support the priority vaccination of cancer patients.

PURPOSE: We aimed to evaluate choroidal thickness (CT) in patients who have recovered from COVID-19 by using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS: We included fifty-eight patients who have recovered from COVID-19 (group 1) and fifty healthy control subjects (group 2) in this prospective study. Best corrected visual acuity, anterior segment and posterior segment examinations of all subjects were performed. CT scan and measurements were taken with the EDI mode of the Spectral Domain OCT device. RESULTS: Of the 108 subjects included in this study, 57 were female and 51 were male. The mean age was similar in both groups (36.10 ± 7.12 and 35.58 ± 7.29, respectively, p = 0.276). Group 1 had the following characteristics: the mean time since diagnosis was 53.18 ± 2.84; it had been 38.48 ± 4.07 days since the PCR test was negative; and all subjects were outpatients. It was detected that the CT of the patients in group 1 decreased in all areas compared to group 2, and this decrease was significant in subfoveal, temporal and inferior areas (257.48 ± 32.79, 273.62 ± 45.04, p = 0.04; 232.96 ± 41.79, 252.76 ± 46.09, p = 0.02, and 245.22 ± 44.58, 271.54 ± 55.07, p = 0.01, respectively). In the retinal nerve fiber layer analysis for group 1, thickening was detected in all areas, although it was not statistically significant, except in the temporal area where it was (superotemporal, superonasal, nasal, inferonasal, inferotemporal, temporal, and global [p = 0 .08, p = 0.45, p = 0.73, p = 0.64, p = 0.74, p = 0.02, and p = 0.10, respectively]). CONCLUSION: For individuals who had recovered from COVID-19, it was found that CT decreased in all areas in these patients. Therefore, this study in which we have demonstrated the decrease in the thickness of the choroidal tissue, a tissue with high blood flow, may contribute to the understanding of the systemic microvascular waste of this disease.

Our study assessed the rate of new and recurrent Chlamydia trachomatis and Neisseria gonorrhoeae infections in the third trimester at an adolescent obstetrics clinic.Between October 2016 and June 2020, routine third-trimester screening for C. trachomatis and N. gonorrhoeae was implemented according to new Canadian recommendations. Urine nucleic acid amplification was performed. Patient records were reviewed retrospectively, and demographic data; pregnancy and delivery characteristics; and information on screening at presentation to care, third-trimester screening (33-38 weeks), and other STI testing was recorded.A total of 115 adolescents (mean age 17.90 ± 1.43 y) with 125 pregnancies presented for care. Twenty-three pregnancies were excluded (12 transferred out and 11 experienced a pregnancy loss). At presentation, screening was performed in 100 of 102 pregnancies: 64 of 100 at13 weeks, 32 of 100 at 13-27 weeks, and 4 of 100 at 28-30 weeks. Nine tested positive for C. trachomatis and none tested positive for N. gonorrhoeae. In the third trimester, there were 3 positive C. trachomatis tests, but all were indicated: test of cure was due for 1 patient, 1 patient had a new sexual partner, and 1 patient presented with symptoms. The remaining 89 of 102 pregnancies were screened (with no other indication) and none were positive for C. trachomatis or N. gonorrhoeae. Ten patients could not be sampled (5 missed, 4 pre-term deliveries, and 1 non-compliant with testing).No cases of C. trachomatis or N. gonorrhoeae infection were identified on third-trimester screening in our study. Adolescent obstetrics providers implementing Canadian screening guidelines may want to monitor their screening results to determine whether their yield warrants universal implementation.

The aim of this study was to evaluate the results of an algorithm that was created to prevent coronavirus disease-2019 (COVID-19) transmission during the management of children with burns in a tertiary pediatric burn center. Children admitted to the burn center between May 2020 and November 2020 were prospectively evaluated for cause, burn depth, TBSA, length of stay, symptoms suggesting COVID-19, suspicious contact history, history of travel abroad, and COVID-19 polymerase chain reaction (PCR) test results. Patients were divided into two groups: unsuspected (group 1) and suspected (group 2), depending on any history of suspicious contact, travel abroad, and/or presence of symptoms. A total of 101 patients were enrolled in the study, which included 59 boys (58.4%) and 42 girls (41.6%). Group 1 included 79 (78.2%) patients, and group 2 consisted of 22 (21.8%) patients. The most common cause of the burns was scald injuries (74.2%). The mean age, TBSA, and length of stay were 4.5 years, 12.0%, and 13.2 days, respectively. Four patients (3.9%) had a positive PCR test (two patients in each group). Comparing groups, males were more commonly found in group 2 (P = .042), but no differences were found for the other variables. No patients or burn center staff members developed COVID-19 during the course of hospitalization. In conclusion, every child should be tested for COVID-19 upon admission to a burn unit, and a modified algorithm should be constructed for the handling and management of pediatric burn patients.

Objectives We aimed to compare the efficiency of the CapitalBioMycobacterium real-time polymerase chain reaction (PCR) detection test with the standard Xpert MTB/RIF assay for the diagnosis of tuberculous meningitis (TBM). Methods We analyzed cerebrospinal fluid (CSF) from 163 patients with suspected TBM that were collected between January 1, 2018, and December 31, 2019. For both tests, we determined the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC). Next, we compared the diagnostic accuracy of the two techniques using clinical diagnosis as a reference standard. Results The sensitivity, specificity, PPV, NPV, and AUC, of the CapitalBio Mycobacterium detection test were 48.5%, 100%, 100%, 29.6%, and 0.74, respectively, when used for the diagnosis of TBM. In comparison, the Xpert MTB/RIF assay returned values of 47.0%, 100%, 100%, 29.0%, and 0.74, respectively. Our analysis showed that the diagnostic accuracies of the CapitalBio Mycobacterium detection test and the Xpert MTB/RIF assay were very similar; the accuracy of both tests for detecting mycobacteria was significantly higher than that associated with acid­fast staining. Conclusions The CapitalBio Mycobacterium real-time PCR detection test has moderate sensitivity and very high specificity for TBM; results are very similar to those generated by the Xpert MTB/RIF assay. We recommend that the CapitalBio PCR test should be used as an initial screening method for TB.

Purpose The purpose of our study was to determine the usability of lung ultrasonography (LUS) in the diagnosis of COVID-19, and to match the morphological features of lesions detected on computed tomography (CT) with the findings observed on LUS. Methods Sixty patients with COVID-19 were included in this prospective study. Patients were examined by radiology and anesthesia clinic specialists for a visual CT score. A LUS 12-zone ultrasonography protocol was applied by the investigator blinded to the CT and PCR test results. The characteristics of abnormal findings and the relationship of lesions to the pleura and the distance to the pleura were investigated. Results Forty-five males and 25 females evaluated within the scope of the study had an average age of 61.2 ± 15.3 years. The total CT score was calculated as 14.3 ± 5.3, and the LUS score was found to be 19.9 ± 7.6. There was a statistically significant positive correlation between the measured LUS and CT scores (r = 0.857, p

Search and find methods*) such as cluster tracing1)-6) or large-scale PCR testing**) of those who exhibit no symptoms or only mild symptoms of COVID-19 is shown by data analysis to be a powerful means to suppress the spread of COVID-19 instead of, or in addition to, lockdown of the entire population. Here we investigate this issue by analyzing the data from some cities and countries and we establish that search and find method is as powerful as lockdown of a city or a country. Moreover, in contrast to lockdown, it neither causes inconvenience to citizens nor does it disrupt the economy. Generally speaking, it is advisable that both social distancing and increased test numbers be employed to suppress spread of the virus. The product of the total test number with the rate of positive cases is the crucial index.

Severe acute respiratory syndrome coronavirus 2 rapid antigen detection (RAD) test kits are widely used as primary screening test in Japan because rapid diagnosis of coronavirus disease 2019 (COVID-19) is critical for infection control. We report cases with RAD test false-positive results in a ward for patients with disabilities. RAD tests potentially evoke hospital operational risk. It is desirable that performing PCR test appropriately when patients admitted to a medical treatment ward with COVID-19 symptoms instead of RAD test.

Objectives Pneumocystis jirovecii pneumonia (PCP) is an opportunistic fungal infection with high morbidity and mortality among people living with HIV. Upper respiratory tract (URT) swabs are routinely taken for testing viral and bacterial pathogens when patients present with respiratory symptoms in our hospital. We conducted a pilot service improvement project to explore the utility of URT swabs for PCP diagnosis using in-house real-time polymerase chain reaction (PCR). Methods Ten URT swab samples obtained from HIV-positive patients with PCP and a positive PCP PCR (AusDiagnostics) from lower respiratory tract (LRT) samples were retrospectively identified. Nine HIV-positive patients with a negative PCR for PCP from LRT samples were identified. Stored aliquots of DNA extracted from these samples were retrieved and tested by an in-house real-time PCR for the presence of PCP DNA. Among PCP-positive cases, URT swabs collected after PCP treatment initiation were excluded from the study. Results In all, 10 URT samples from PCP-positive patients and nine URT samples from PCP-negative patients were tested for PCP by real-time PCR. Eighteen out of 19 URT sample had a concordant result with the LRT samples. The sensitivity and specificity for URT sample PCR were 90% [confidence interval (CI): 55.50-99.75%] and 100% (CI: 66.37-100%). The positive predictive value was 100% and the negative predictive value was 90.9% (CI: 60.90-98.47%). Conclusions Upper respiratory tract swab can reliably detect PCP DNA on real-time PCR among people living with HIV with PCP.

Background Pneumocystis pneumonia (PCP) is a disease caused by the opportunistic infection of the fungus Pneumocystis jirovecii. Several PCR methods have been developed to aid in the diagnosis of PCP. In this study, we evaluated the performance of a real-time PCR in the diagnosis of PCP, in patients with various underlying diseases. Methods Ninety-seven BAL samples and 94 sputum samples from 191 patients were used in the study. Patients were classified as PCP (121 patients) or non-PCP (70 patients) based on their clinical and radiological presentations. Results Real time PCR amplified the P. jirovecii mitochondrial large-subunit rRNA gene with a detection limit of 68 copies of DNA per reaction. Non-PCP pathogens including 32 different fungi and bacteria were also evaluated. Overall, 71.9% of the samples from PCP patients and 14.5% of those from non-PCP patients were positive for the PCR test with a CT value of the real-time PCR below 45. The main underlying diseases of the patients were hematological or solid malignancies (47.1%) and HIV infection (8.9%). The CT values of the test were significantly lower in BAL samples from PCP patients than those from non-PCP patients (p = 0.024). No non-PCP patient had a CT value below 30, whereas samples from 24.8% of PCP patients with underlying diseases had a CT value below 30. Conclusion Since false positive PCR results were obtained, perhaps due to colonization, we suggest that the diagnosis of PCP should be based on a combination of clinical symptoms, underlying diseases, and PCR results.

Purpose Based on the recent literature, chest computed tomography (CT) examination could aid for management of patients during COVID-19 pandemic. However, the role of chest CT in management of COVID-19 patients is not exactly the same for medical or surgical specialties. In orthopaedic or trauma emergency, abdomen, pelvis, cervical, dorsal, and lumbar spine CT are performed to investigate patients; the result is a thoracic CT scan incorporating usually the thorax; however, information about lung parenchyma can be obtained on this thorax CT, and manifestations of COVID-19 can be diagnosed. The objective of our study was to evaluate this role in orthopedic patients to familiarize orthopaedists with the value and limits of thoracic CT in orthopaedic surgery. Materials and methods Among the 1397 chest CT scans performed during the pandemic period from 1 March 2020 to 10 May 2020, in two centres with orthopaedic surgery, we selected all the 118 thoracic or chest CT performed for patients who presented to the Emergency Department of the hospital with a diagnosis of trauma for orthopaedic surgical treatment. Thirty-nine of these 118 patients were tested with PCR for the diagnosis of COVID-19 infection. Depending on clinical status (symptomatic or non-symptomatic), the information useful for the orthopaedist surgeon and obtained from the Chest CT scan according to the result of the PCR (gold standard) was graded from 0 (no or low value) to 3 (high value). The potential risks of chest CT as exposure to radiation, and specific pathway were analyzed and discussed. A group of patients treated during a previous similar period (1 March 2018 to 15 April 2018) was used as control for evaluation of the increase of CT scanning during the COVID-19 pandemic. Results Among the 118 patients with chest CT, there were 16 patients with positive COVID-19 chest CT findings, and 102 patients with negative chest CT scan. With PCR results as reference, the sensitivity, specificity, positive predictive value of chest CT in indicating COVID-19 infection were 81%, 93%, and 86%, respectively (p = 0.001). A useful information for the orthopaedic surgeon (graded as 1 for 71 cases, as 2 for 5 cases, and as 3 for 11 cases) was obtained from 118 chest CT scans for 87 (74%) patients, while the CT was no value in 30 (25%) cases, and negative value in one (1%) case. Roughly 20% of the total number of CT scanner performed over the pandemic period was dedicated to COVID-19, but only 2% were for orthopaedic or trauma patients. However, this was ten times higher than during the previous control period of comparison. Conclusion Although extremely valuable for surgery management, these results should not be overstated. The CT findings studied are not specific for COVID-19, and the positive predictive value of CT will be low unless disease prevalence is high, which was the case during this period.

Objective Infection by Primate erythroparvovirus 1, generally known Parvovirus B19, is highly prevalent worldwide. Although infection by this virus will not be clinically problematic in most cases, new infections during pregnancy could result in serious repercussions in the fetus. Serologic and PCR-based methods are among the available approaches for diagnosis of Parvovirus B19 infection. In this regard, the present study is aimed to investigate the frequency of Parvovirus B19 infection by these two techniques in pregnant women of Zanjan. Materials and methods In this cross sectional-descriptive study, 110 pregnant women referring to Mousavi hospital in Zanjan during one year were evaluated in terms of serologic and Real-Time PCR test results in search for Parvovirus B19 infection. The rate of positive IgG and IgM were determined in women and the Real-Time PCR results were reported. Results Overall, 18.2% of participants were above 35 years old and 4.5% of them were younger than 18 years old. 41 (44.1%) and 2 (1.8%) cases had positive anti-Parvovirus B19 IgG and IgM, respectively. Real-Time PCR results were negative in all the studied samples. Conclusion Based on the findings of this study, prevalence of acute Parvovirus B19 infection was 0 and 2% based on Real-Time PCR and IgM tests, respectively. About 40% of pregnant women had experienced infection with this virus before.

The most widely used test for the diagnosis of SARS-CoV-2 infection is a PCR test. PCR has very high sensitivity and is able to detect very low amounts of RNA. However, many individuals receiving a positive test result in a context of a PCR-based surveillance might be infected with SARS-CoV-2, but they are not contagious at the time of the test. The question arises regards if the cost effective, portable rapid antigen tests (RATs) have a better performance than PCR in identification of infectious individuals. In this direction, we examined the diagnostic performance of RATs from 14 different manufacturers in 400 clinical samples with known rRT-PCR cycles threshold (cT) and 50 control samples. Substantial variability was observed in the limit of detection (LOD) of different RATs (cT = 26.8–34.7). The fluorescence-based RAT exhibited a LOD of cT = 34.7. The use of the most effective RATs leads to true positive rates (sensitivities) of 99.1% and 90.9% for samples with cT ≤ 30 and cT ≤ 33, respectively, percentages that can guarantee a sensitivity high enough to identify contagious patients. RAT testing may also substantially reduce the quarantine period for infected individuals without compromising personal or public safety.

In this study, we quantitatively assessed the effectiveness of systems for COVID-19 testing in small groups of sport teams that are semi-isolated from the general population by countermeasures against infection. Two types of group were assumed, and the dynamics of infection within each group was modeled by using a compartment model of infectious disease. One group (Group A) comprised domestic professional sports teams that play many games over a season while remaining within a relatively small region. Polymerase chain reaction (PCR) tests were routinely conducted once every 2 weeks, and the number of infected individuals that could not be removed after identification by testing or checking for symptoms was defined as the risk. The other group (Group B) comprised teams that travel across borders for mass-gathering events like the Olympic and Paralympic Games. The teams were isolated for 2 weeks at their destination; frequent testing and checking for symptoms was conducted, and any infected individuals were removed. The number of infected individuals participating in games after the isolation period was defined as the risk. In Group A, the number of infected individuals detected by routinely conducted PCR testing was lower than the number of infected individuals detected by checking for symptoms, indicating that routine testing every 2 weeks was not very effective. In Group B, daily PCR testing was the most effective, followed by daily antigen testing. Dual testing, in which individuals with a positive antigen test were given an additional PCR test, was the least effective with an effect equal to PCR testing every other day. These results indicate that repeated testing does not necessarily increase the detection of infected individuals.

The impact of the COVID-19 pandemic in sport has been the subject of numerous studies over the past two years. However, knowledge about the direct impact of COVID-19 infection on the performance of athletes is limited, and the importance of studies on this topic is crucial during the current pandemic era. This study aimed to evaluate the changes in the match running performance (MRP) of professional soccer players that occurred as a result of COVID-19 infection after fulfilling all of the prerequisites for a safe return to play (RTP). The participants were 47 professional soccer players from a team which competed in first Croatian division (21.6 years old on average) during the 2020/21 season. The total sample was divided into two subgroups based on the results of a PCR test for COVID-19, where 31 players tested positive (infected) and 16 tested negative. We observed the PCR test results (positive vs. negative PCR), the number of days needed to return to the team, number of days needed to RTP after quarantine and isolation, and MRP (10 variables measured by a global positioning system). The number of days where the infected players were not included in the team ranged from 7 to 51 (Median: 12). Significant pre- to post-COVID differences in MRP for infected players were only found for high-intensity accelerations and high-intensity decelerations (t-test = 2.11 and 2.13, respectively; p < 0.05, moderate effect size differences), with poorer performance in the post-COVID period. Since a decrease of the MRP as a result of COVID-19 infection was only noted in two variables, we can highlight appropriateness of the applied RTP. However, further adaptations and improvements of the RTP are needed with regard to high-intensity activities., peer-reviewed

The purpose of this study was to characterize the diagnostic performance of a newly developed enzyme-linked immunosorbent assay (ELISA) for detection of SARS-CoV-2 nucleocapsid protein (NP) in blood. Blood samples were collected during hospitalization of 165 inpatients with PCR-confirmed SARS-CoV-2 infection and from 505 outpatients predominantly with relevant symptoms of COVID-19 simultaneously with PCR testing. For the 143 inpatients who had their first blood sample collected within 2 weeks after PCR-confirmed infection, the diagnostic sensitivity of the ELISA was 91.6%. The mean NP concentration of the 131 ELISA-positive blood samples was 1,734 pg/ml (range, 10 to 3,840 pg/ml). An exponential decline in NP concentration was observed for 368 blood samples collected over the first 4 weeks after PCR-confirmed SARS-CoV-2 infection, and all blood samples taken later had an NP concentration below the 10-pg/ml diagnostic cutoff. The diagnostic sensitivity of the ELISA was 81.4% for the 43 blood samples collected from outpatients with a simultaneous positive PCR test, and the mean NP concentration of the 35 ELISA-positive samples was 157 pg/ml (range, 10 to 1,377 pg/ml). For the 462 outpatients with a simultaneous negative PCR test, the diagnostic specificity of the ELISA was 99.8%. In conclusion, the SARS-CoV-2 NP ELISA is a suitable laboratory diagnostic test for COVID-19, particularly for hospitals, where blood samples are readily available and screening of serum or plasma by ELISA can facilitate prevention of nosocomial infections and reduce the requirement for laborious swab sampling and subsequent PCR analysis to confirmatory tests only.

Background Most children recover quickly after coronavirus disease 2019 (COVID-19), but some may have ongoing symptoms. Follow-up studies have been limited by small sample sizes and lack of appropriate controls. Methods We used national testing data to identify children aged 2–16 years with a SARS-CoV-2 PCR test during 1–7 January 2021 and randomly selected 1500 PCR-positive cases and 1500 matched PCR-negative controls. Parents were asked to complete a questionnaire about the acute illness and prespecified neurological, dermatological, sensory, respiratory, cardiovascular, gastrointestinal, mental health (including emotional and behavioral well-being), and other symptoms experienced ≥5 times at 1 month after the PCR test. Results Overall, 35.0% (859/2456) completed the questionnaire, including 38.0% (472/1242) of cases and 32% (387/1214) of controls, of whom 68% (320/472) and 40% (154/387) were symptomatic, respectively. The most prevalent acute symptoms were cough (249/859, 29.0%), fever (236/859, 27.5%), headache (236/859, 27.4%), and fatigue (231/859, 26.9%). One month later, 21/320 (6.7%) of symptomatic cases and 6/154 (4.2%) of symptomatic controls (P = .24) experienced ongoing symptoms. Of the 65 ongoing symptoms solicited, 3 clusters were significantly (P Conclusions Children with symptomatic COVID-19 had a slightly higher prevalence of ongoing symptoms than symptomatic controls, and not as high as previously reported. Healthcare resources should be prioritized to support the mental health of children.

lt;bgt;Background and Objective:lt;/bgt; Coronavirus disease 2019 (COVID-19), also known as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), became a global health issue that influenced the lives of billions of people all over the world. The goal of this study was to investigate the clinical findings and routine laboratory evaluations of COVID-19 patients in both average- and high-altitude settings in Saudi Arabia.lt;bgt;Materials and Methods:lt;/bgt; A comparative study to explore the clinical characteristics and Laboratory tests results of COVID-19 patients at both high and average altitudes in Saudi Arabia has been conducted. The study included a total number of 103 patients (53 patients comprising the high-altitude group living in Taif, Saudi Arabia and 50 patients comprising the average-altitude group living in Al Ahsa, Saudi Arabia) were included in the study. Patients were diagnosed with SARS-CoV-2-positive by PCR test. Clinical characteristics, laboratory test results and symptoms of adult patients were collected and expressed as mean and standard deviation. Statistical analysis was done using SPSS software to compare between both groups and significance was considered when the p-value is less than 0.05.lt;bgt;Results:lt;/bgt; Approximately 55.3% of the total cases were male with a mean age of 40.16±12.47 years. There were highly statistically significant differences between the groups in age, heart rate (p0.001). There were also statistically significant differences between the groups in temperature, SpOlt;subgt;2lt;/subgt;, fever, myalgia, shortness of breath and loss of smell and taste.lt;bgt;Conclusion:lt;/bgt; The current study provides an understanding of the clinical and laboratory investigations of COVID-19 patients in two regions (high altitude and average altitude) in Saudi Arabia.

Introduction COVID19 has raised concerns for resource allocation across various sectors of healthcare. At the frontlines, emergency departments are required to triage a wide range of acuity and non-specific symptomology. Methods This retrospective study aimed to pave the way for more concrete detection and triage of patients by analyzing symptomology, physical findings, diagnostic testing and relevant hospital course of the 458 suspected cases that initially presented to an academic level one trauma center emergency department between March and August 2020. A total of 202 COVID positive cases were analyzed. Results The most common symptoms were cough (70.63%), fatigue (77%), and shortness of breath (59%). There was a significantly higher percentage of abnormal chest imaging in inpatient groups compared to the ED discharge group (42.86% vs 79%, p

The COVID-19 outbreak began in December 2019 and has dreadfully affected our lives since then. More than three million lives have been engulfed by this newest member of the corona virus family. With the emergence of continuously mutating variants of this virus, it is still indispensable to successfully diagnose the virus at early stages. Although the primary technique for the diagnosis is the PCR test, the non-contact methods utilizing the chest radiographs and CT scans are always preferred. Artificial intelligence, in this regard, plays an essential role in the early and accurate detection of COVID-19 using pulmonary images. In this research, a transfer learning technique with fine tuning was utilized for the detection and classification of COVID-19. Four pre-trained models i.e., VGG16, DenseNet-121, ResNet-50, and MobileNet were used. The aforementioned deep neural networks were trained using the dataset (available on Kaggle) of 7232 (COVID-19 and normal) chest X-ray images. An indigenous dataset of 450 chest X-ray images of Pakistani patients was collected and used for testing and prediction purposes. Various important parameters, e.g., recall, specificity, F1-score, precision, loss graphs, and confusion matrices were calculated to validate the accuracy of the models. The achieved accuracies of VGG16, ResNet-50, DenseNet-121, and MobileNet are 83.27%, 92.48%, 96.49%, and 96.48%, respectively. In order to display feature maps that depict the decomposition process of an input image into various filters, a visualization of the intermediate activations is performed. Finally, the Grad-CAM technique was applied to create class-specific heatmap images in order to highlight the features extracted in the X-ray images. Various optimizers were used for error minimization purposes. DenseNet-121 outperformed the other three models in terms of both accuracy and prediction.

Considering the increasing prevalence and burden of coronavirus disease 2019 (COVID-19) disease and false-negative results in routine reverse transcription-polymerase chain reaction (RT-PCR) tests, additional diagnostic methods are needed to diagnose active cases of this disease. This prospective study was conducted on patients, in whom clinical and radiological symptoms/signs were in favor of COVID-19 while their first PCR test was negative. Later on, a second RT-PCR was performed and serological evaluation was carried out and results were compared with each other. Out of 707 patients who had been referred to the hospital and were clinically and radiologically suspicious of disease, 137 patients with negative RT-PCR tests entered the study. RT-PCR assay became positive for the second time in 45 (32.8%). Anti-COVID-19 IgM and IgG antibodies were positive in 83 (60.6%) and 86 (62.8%) patients, respectively. Finally, it was determined that serological test was diagnostic in 73% of patients and the diagnostic yield of serology was significantly higher after the first week of illness (54.8% in the first week and 88% after that). Taking advantage of both serological tests and RT-PCR helps in diagnosing 83.9% of cases. Based on the present study, the serology may be useful as a complementary test and in parallel to RT-PCR assay for diagnosis of COVID-19 among admitted symptomatic cases.

Introduccion La COVID-19 se ha convertido en una amenaza para la salud publica mundial. Sin embargo, las formas graves en ninos son poco frecuentes. Se presenta el caso de un lactante con sindrome inflamatorio multisistemico relacionado con COVID-19. Caso clinico Lactante de 8 meses que estuvo en contacto con adultos positivos para COVID-19. El lactante inicio con una forma leve de la enfermedad que progreso con rapidez a una forma critica de presentacion inicialmente con estado epileptico, y a su ingreso con evidencia de inflamacion en laboratorios, afeccion sistemica grave con falla multiorganica y prueba de reaccion en cadena de la polimerasa para SARS-CoV-2 nasofaringea positiva. El lactante fallecio 7 dias despues de su ingreso. Conclusiones El espectro de presentacion de la COVID-19 en ninos menores de 1 ano es variable y aun no se cuentan con criterios consensuados para el diagnostico y el tratamiento. Todo lactante con enfermedad grave con compromiso multiorganico al ingreso en tiempos de pandemia obliga a realizar una meticulosa historia clinica y considerar la infeccion por SARS-CoV-2 hasta su confirmacion. Background COVID-19 has become a threat to global public health. However, severe forms of COVID-19 presentation in children are rare. We present the case of an infant with COVID 19-related multisystem inflammatory syndrome. Case report We describe the case of an 8-month-old infant who had contact with COVID-19 positive adults. The infant began with mild symptoms of the disease but rapidly progressed to a critical form of presentation:initially with epileptic status, and upon admission with laboratory evidence of inflammation, severe systemic condition with multiple organ failure, and a positive nasopharyngeal SARS-CoV-2 PCR test. The infant died 7 days after admission. Conclusions The spectrum of COVID-19 presentation in children under one year of age is variable, and there are still no established criteria for diagnosis and treatment. All infants presenting a severe disease with multiple organ involvement at admission in times of pandemic require a thorough medical history to consider SARS-CoV-2 infection until proven otherwise.

OBJECTIVES: This study aimed to investigate public use of lateral flow tests (LFT) and polymerase chain reaction (PCR) tests when experiencing key COVID-19 symptoms. STUDY DESIGN: In this study, data from two waves of a cross-sectional nationally representative online survey (data collected 1 and 2 June, and 14 and 15 June 2021; n = 3665 adults aged ≥18 years living in England or Scotland) were used. METHODS: We report data investigating which type of test, if any, the public think Government guidance asks people to use if they have COVID-19 symptoms. In people with key COVID-19 symptoms (high temperature / fever; new, continuous cough; loss of sense of smell; loss of taste), we also describe the uptake of testing, if any. RESULTS: Ten percent of respondents thought Government guidance stated that they should take an LFT if symptomatic, whereas 18% of people thought that they should take a PCR test; 60% of people thought they should take both types of test (12% did not select either option). In people who were symptomatic, 32% reported taking a test to confirm whether they had COVID-19. Of these, 53% reported taking a PCR test and 44% reported taking an LFT. CONCLUSIONS: Despite Government guidance stating that anyone with key COVID-19 symptoms should complete a PCR test, a significant percentage of the population use LFT tests when symptomatic. Communications should emphasise the superiority of, and need for, PCR tests in people with symptoms.

To address the need for simple, safe, sensitive, and scalable SARS-CoV-2 tests, we validated and implemented a PCR test that uses a saliva collection kit use at home. Individuals self-collected 300 μl saliva in vials containing Darnell Rockefeller University Laboratory (DRUL) buffer and extracted RNA was assayed by RT-PCR (the DRUL saliva assay). The limit of detection was confirmed to be 1 viral copy/μl in 20 of 20 replicate extractions. Viral RNA was stable in DRUL buffer at room temperature up to seven days after sample collection, and safety studies demonstrated that DRUL buffer immediately inactivated virus at concentrations up to 2.75x106 PFU/ml. Results from SARS-CoV-2 positive nasopharyngeal (NP) swab samples collected in viral transport media and assayed with a standard FDA Emergency Use Authorization (EUA) test were highly correlated with samples placed in DRUL buffer. Direct comparison of results from 162 individuals tested by FDA EUA oropharyngeal (OP) or NP swabs with co-collected saliva samples identified four otherwise unidentified positive cases in DRUL buffer. Over six months, we collected 3,724 samples from individuals ranging from 3 months to 92 years of age. This included collecting weekly samples over 10 weeks from teachers, children, and parents from a pre-school program, which allowed its safe reopening while at-risk pods were quarantined. In sum, we validated a simple, sensitive, stable, and safe PCR-based test using a self-collected saliva sample as a valuable tool for clinical diagnosis and screening at workplaces and schools.

OBJECTIVES: This study aims to determine the prognostic significance of the lymphocyte/mean platelet volume ratio (LMR) in terms of the clinical course of the disease in patients with COVID-19. METHODS: Patients over 18 who were evaluated for COVID-19 during the period from April 1, to April 30, 2020 were retrospectively scanned. Patients with at least 1 positive PCR test result were as assigned to Group 1 while patients with negative test results were assigned to Group 2. The LMR ratio was calculated by dividing the lymphocyte value by that of MPV. The relationship between LMR, severity of patients' CT findings and 28-day mortality was evaluated. RESULTS: A total of 938 patients were included in the study. It was observed that the lymphocyte and LMR levels were significantly different in those who died within 28 days (p < 0.001, p ≤ 0.001). In the ROC analysis for the LMR level, the area under the curve (AUC) was found to be 0.737 (95% CI 0.639‒0.834). When the cut­off value of LMR was 0.045, the sensitivity was found to be 99.0 % and specificity was 15.2 %. CONCLUSION: LMR can be a guide in multiple cases of care provided to critical patients, as is the case in the COVID-19 pandemic and can be used in recognizing critical patients (Tab. 5, Fig. 1, Ref. 21).

The gold standard for the diagnosis of coronavirus disease 2019 (COVID-19) is a nucleic acid detection test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may occasionally reveal false-positive or false-negative results. Herein, we describe a case of a patient infected with human coronavirus NL63 (HCoV-NL63) who was falsely diagnosed with COVID-19 using the Ampdirect™ 2019-nCoV detection kit (Shimadzu Corporation, Japan) and SARS-CoV-2 Detection Kit (TOYOBO co., ltd.), and was admitted to a COVID-19 hospital ward. We suspected a cross-reaction between HCoV-NL63 and SARS-CoV-2; however, the reported genome sequences of HCoV-NL63 and N1/N2 primers for SARS-CoV-2 do not correspond. Thus, the PCR result was supposed to be a false positive possibly due to contamination or human error. Although the issue of a false-negative result has been the focus of much attention to prevent the spread of the disease, a false positive is fraught with problems as well. Physicians should recognize that unnecessary isolation violates human rights and a careful diagnosis is indispensable when the results of laboratory testing for COVID-19 are unclear. Generally, in cases such as a duplicate PCR test was partially positive, either N1 or N2 alone was positive, PCR testing for two or more target regions resulted in a positive only for single region, a high cycle threshold >35 was obtained, a false positive should be suspected. Especially, when these conditions coincide, we should recognize the high likelihood of a false positive.

Author(s): Bonadio, William; Jackson, Kaedrea; Gottlieb, Lindsey; Legome, Eric | Abstract: Introduction: We assessed the utility of an emergency department (ED) protocol using clinical parameters to rapidly distinguish likelihood of novel coronavirus 2019 (COVID-19) infection; the applicability aimed to stratify infectious-risk pre-polymerase chain reaction (PCR) test results and accurately guide early patient cohorting decisions.Methods: We performed this prospective study over a two-month period during the initial surge of the 2020 COVID-19 pandemic in a busy urban ED of patients presenting with respiratory symptoms who were admitted for in-patient care. Per protocol, each patient received assessment consisting of five clinical parameters: presence of fever; hypoxia; cough; shortness of breath/dyspnea; and performance of a chest radiograph to assess for bilateral pulmonary infiltrates. All patients received nasopharyngeal COVID-19 PCR testing.Results: Of 283 patients studied, 221 (78%) were PCR+ and 62 (22%) PCR-. Chest radiograph revealed bilateral pulmonary infiltrates in 85%, which was significantly more common in PCR+ (94%) vs PCR- (52%) patients (P l 0.0001). The rate of manifesting all five positive clinical parameters was significantly greater in PCR+ (63%) vs PCR- (6.5%) patients (P l 0.0001). For PCR+ outcome, the presence of all five positive clinical parameters had a specificity of 94%, positive predictive value of 98%, and positive likelihood ratio of 10.Conclusions: Using an ED protocol to rapidly assess five clinical parameters accurately distinguishes likelihood of COVID-19 infection prior to PCR test results, and can be used to augment early patient cohorting decisions.

Background: During the COVID-19 pandemic, many patients admitted to hospital for treatment have recovered and been discharged; however, in some instances, these same patients are re-admitted due to a second fever or a positive COVID-19 PCR test result. To ascertain whether it is necessary to treat these patients in hospitals, especially in asymptomatic cases, we summarize and analyze the clinical and treatment characteristics of patients re-admitted to hospital with a second COVID-19 infection.Methods: Of the 141 COVID-19 cases admitted to the Wenzhou Central Hospital between January 17, 2020, to March 5, 2020, which were followed until March 30, 2020, 12 patients were re-admitted with a second COVID-19 infection. Data was collected and analyzed from their clinical records, lab indexes, commuted tomography (CT), and treatment strategies.Results: Most of the 141 patients had positive outcomes from treatment, with only 12 (8.5%) being re-admitted. In this sub-group: one (8.3%) had a fever, a high white blood cell count (WBC), and progressive CT changes; and one (8.3%) had increased transaminase. The PCR tests of these two patients returned negative results. Another 10 patients were admitted due to a positive PCR test result, seven of which were clinically asymptomatic. Compared to the CT imaging following their initial discharge, the CT imaging of all patients was significantly improved, and none required additional oxygen or mechanical ventilation during their second course of treatment.Conclusions: The prognoses of the re-admitted patients were good with no serious cases. We conclude that home treatment with concentrated medical observation is a safe and feasible course of treatment if the patient returns a positive PCR test result but does not display serious clinical symptoms. During medical observation, patients with underlying conditions should remain a primary focus, but most do not need to be re-admitted to the hospital.

Aims The objective of the present study was to investigate the presence of SARS-CoV-2 in aerosol and COVID-19 contamination distance asssociated with ultrasonic scaling and tooth preparation. Methods Twenty-four patients with COVID-19 were included in this study. Removal of supragingival plaque with ultrasonic instruments for 10 minutes and high-speed air-turbine using for the simulation of cutting the maxillary right canine tooth with a round diamond bur for 5 minutes were performed. Patients were randomly assigned to 2 groups: In group A, medium-volume suction was used during treatment. In group B, high-volume suction with an aerosol cannula was added to medium-volume suction. Prior to treatment, 5 glass petri dishes containing viral transport medium were placed in the operating room. After treatment, petri dishes were immediately delivered to a microbiology laboratory for real-time polymerase chain reaction (RT-PCR) analysis. Results RT-PCR test results were negative for all specimens in group B. However, 5 positive test results for COVID-19 were detected in group A specimens. Conclusions Suction with an aerosol cannula is very important to prevent COVID-19 viral contamination via aerosol. In addition, a high-volume suction capacity (air volume) of 150 mm Hg or 325 L/min is sufficient for elimination of viral contamination. Thus, high-volume suction should be used during dental treatments in COVID-19 patients.

From the point of view of the pandemic officer of a 300-bed specialty care hospital, the first year of the SARS-CoV‑2 (Severe Acute Respiratory Syndrome Coronavirus Type 2) pandemic with all the challenges for daily clinical routine was reviewed on the basis of the data collected with the aim of making future pandemic management easier to plan.The Caritas Hospital St. Josef in Regensburg employs around 1330 employees and treats almost 20,000 inpatients annually. All records of the pandemic officer between 1 March 2020 and 28 February 2021 were included in the present descriptive study.In all, 280 SARS-CoV-2-positive patients (mean age 68 ± 19 years) were treated during the observation period; 81% (n = 227) of these were treated as inpatients between November 2020 and February 2021. In addition to the analysis of these patients, an analysis of the test concept was carried out, both for the patients (53% of the tests in the so-called 2nd wave) and for the employees; 1633 PCR tests were carried out, with 5.6% of all employees being infected with SARS-CoV‑2 in the course of the pandemic. In addition, other measures such as reducing the surgical program and other general measures were evaluated.Many established processes had to be changed in the hospital during the pandemic. Both staff shortages due to SARS-CoV-2-positive employees and the quarantine measures of contact persons led to further tension in the already tight staffing levels, especially in the nursing care sector, and made patient care more difficult. The test concept in the hospital was very complex and asymptomatic tests in particular showed a low hit rate, while being associated with high personnel costs.HINTERGRUND: Aus dem Blickwinkel der Pandemiebeauftragten eines Schwerpunktkrankenhauses mit 300 Betten wurde das erste Jahr der SARS-CoV‑2(„Severe Acute Respiratory Syndrome Coronavirus Type 2“)-Pandemie mit allen Herausforderungen für den klinischen Alltag anhand der erhobenen Datenlage mit dem Ziel aufgearbeitet, das zukünftige Pandemiemanagement besser planbar zu machen.Das Caritas-Krankenhaus St. Josef in Regensburg beschäftigt rund 1330 Mitarbeitende (MA) und versorgt jährlich fast 20.000 stationäre Patienten. Sämtliche Aufzeichnungen des Pandemiebeauftragten zwischen dem 01.03.2020 und 28.02.2021 wurden in die vorliegende deskriptive Studie eingeschlossen.Im Beobachtungszeitraum wurden 280 SARS-CoV-2-positiv getestete Patienten (durchschnittliches Alter 68 ± 19 Jahre) behandelt. Zwischen 11/2020 und 02/2021 wurden 81 % (n = 227) dieser Patienten im Haus behandelt. Neben der Analyse dieser Patienten erfolgte eine Analyse des Testkonzepts sowohl der Patienten (53 % der Tests i. R. der sog. 2. Welle) als auch der MA; hier erfolgten 1633 PCR-Tests, wobei sich 5,6 % aller MA im Verlauf der Pandemie mit SARS-CoV‑2 infizierten. Zudem wurden auch weitere Maßnahmen wie die Reduktion des OP-Programms und andere Allgemeinmaßnahmen im Haus evaluiert.Viele etablierte Prozesse mussten im Krankenhaus während der Pandemie verändert werden. Sowohl der Ausfall der positiv getesteten MA wie auch die Quarantänezeiten von Kontaktpersonen führten zu einer weiteren Anspannung der insbesondere im Pflegesektor ohnehin engen Personaldecke und erschwerte die Patientenversorgung. Das Testkonzept im Krankenhaus war sehr komplex und gerade asymptomatische Tests wiesen eine geringe Trefferquote bei gleichzeitig hohem Personalaufwand auf.

A door-to-door survey was organised in Cuenca, Ecuador, to determine the prevalence of COVID-19 infection and adherence of the population to COVID-19 preventive measures. A total of 2457 persons participated in the study, 584 (23.7%) reported having experienced at least one flu-like symptom since the onset of the pandemic. The maximum SARS-CoV-2 seroprevalence in Cuenca was 13.2% (CI: 12–14.6%) (IgM or IgG positive). Considering PCR confirmed infections, the prevalence was 11% (CI: 10–12.4%). There was no significant difference in seroprevalence between rural and urban areas. Participants aged 35–49 years old, living with a COVID-19 positive person, at least six people in a household, physical contact with someone outside the household, a contact with a person outside the home with flu-like symptoms, using public transport, and not having enough resources for living, significantly increased the odds for SARS-CoV-2 seropositivity. Overall, there was good adherence to COVID-19 preventive measures. Having known someone who tested positive for COVID-19, having a primary or secondary level of education, and having enough resources for living, significantly increased the odds for higher adherence. In conclusion, despite good overall adherence of the population of Cuenca with COVID-19 preventive measures, our study suggests high ongoing COVID-19 transmission in Cuenca, particularly in certain parishes. Prevention should not only focus on behavioural change, but on intensified testing strategies in demographical risk groups.

BackgroundRoutine 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)

Viral tests including polymerase chain reaction (PCR) tests are recommended to diagnose COVID-19 infection during the acute phase of infection. A test should have high sensitivity; however, the sensitivity of the PCR test is highly influenced by viral load, which changes over time. Because it is difficult to collect data before the onset of symptoms, the current literature on the sensitivity of the PCR test before symptom onset is limited. In this study, we used a viral dynamics model to track the probability of failing to detect a case of PCR testing over time, including the presymptomatic period. The model was parametrized by using longitudinal viral load data collected from 30 hospitalized patients. The probability of failing to detect a case decreased toward symptom onset, and the lowest probability was observed 2 days after symptom onset and increased afterwards. The probability on the day of symptom onset was 1.0% (95% CI: 0.5 to 1.9) and that 2 days before symptom onset was 60.2% (95% CI: 57.1 to 63.2). Our study suggests that the diagnosis of COVID-19 by PCR testing should be done carefully, especially when the test is performed before or way after symptom onset. Further study is needed of patient groups with potentially different viral dynamics, such as asymptomatic cases.

Rapid point-of-care (POC) quantification of low virus RNA load would significantly reduce the turn-around time for the PCR test and help contain a fast-spreading epidemic. Herein, we report a droplet digital PCR (ddPCR) platform that can achieve this sensitivity and rapidity without bulky lab-bound equipment. The key technology is a flattened pipette tip with an elliptical cross-section, which extends a high aspect-ratio microfluidic chip design to pipette scale, for rapid (

To assess the effectiveness of the containment strategies proposed in Japan, an SEIAQR (susceptible-exposed-infected-asymptomatic-quarantined-recovered) model was established to simulate the transmission of COVID-19. We divided the spread of COVID-19 in Japan into different stages based on policies. The effective reproduction number Re and the transmission parameters were determined to evaluate the measures conducted by the Japanese Government during these periods. On 7 April 2020, the Japanese authority declared a state of emergency to control the rapid development of the pandemic. Based on the simulation results, the spread of COVID-19 in Japan can be inhibited by containment actions during the state of emergency. The effective reproduction number Re reduced from 1.99 (before the state of emergency) to 0.92 (after the state of emergency). The transmission parameters were fitted and characterized with quantifiable variables including the ratio of untracked cases, the PCR test index and the proportion of COCOA app users (official contact confirming application). The impact of these variables on the control of COVID-19 was investigated in the modelling analysis. On 8 January 2021, the Japanese Government declared another state of emergency. The simulated results demonstrated that the spread could be controlled in May by keeping the same strategies. A higher intensity of PCR testing was suggested, and a larger proportion of COCOA app users should reduce the final number of infections and the time needed to control the spread of COVID-19.

Background In a response to the pandemic, urgent care centers (UCCs) have gained a critical role as a common location for COVID-19 testing. We sought to characterize the changes in testing accessibility at UCCs between March and August 2020 on the basis of testing availability (including rapid antigen testing), wait time for test results, cost of visits, and cost of tests. Methods Data were collected using a secret shopper methodology. Researchers contacted 250 UCCs in 10 states. Investigators used a standardized script to survey centers on their COVID-19 testing availability and policies. UCCs were initially contacted in March and re-called in August. T-tests and chi-square tests were conducted to identify differences between March and August data and differences by center classification. Results Our results indicate that both polymerase chain reaction (PCR) tests to detect COVID-19 genetic material and rapid antigen COVID-19 tests have increased in availability. However, wait times for PCR test results have significantly increased to an average of 5.79 days. Additionally, a high proportion of UCCs continue to charge for tests and visits and no significant decrease was found in the proportion of UCCs that charge for COVID-19 testing from March to August. Further, no state reported a majority of UCCs with rapid testing available, indicating an overall lack of rapid testing. Conclusions From March to August, COVID-19 testing availability gradually improved. However, many barriers lie in access to COVID-19 testing, including testing costs, visit costs, and overall lack of availability of rapid testing in the majority of UCCs. Despite the passage of the CARES Act, these results suggest that there is room for additional policy to improve accessibility to testing, specifically rapid testing.

The purpose of the present study was to create a real-time PCR test system allowing simultaneous detection of nontuberculous mycobacteria (NTM) and Mycobacterium tuberculosis complex (MTBC) both in culture and sputum. NTM cultures (18 strains, 18 species), MTBC cultures (16 strains, 2 species) and non-mycobacterial microorganisms from the collection of the Central Research TB Institute (CTRI) were used for the preliminary evaluation of the test system. 301 NTM cultures from patients with mycobacteriosis were used to assess the sensitivity of the developed test system. Clinical respiratory samples (sputum) from 104 patients with mycobacteriosis, 3627 patients with tuberculosis and 118 patients with other lung diseases were used for diagnostic sensitivity and specificity testing. The specificity and sensitivity of the assay for MTBC was found to be 100% both in culture and sputum samples; for NTM, the specificity was 100% in culture and sputum, the sensitivity reached 100% in culture and 73.1% in sputum samples. Positive predictive value (PPV) and negative predictive value (NPV) of the assay for culture were both 100%, for clinical material 100% and 80.8%, respectively. The limit of detection at the probability of detection 95% (LoD95%) was estimated to be 16 cfu/ml for M. tuberculosis H37RV and 1200 cfu/ml for M. avium.

Objective: Aims to describe the initial symptoms most related to the prognosis of Covid-19. Design: This is a retrospective cross sectional, quantitative, data analyzed study. Site: This study was made in the family medicine centers (n = 82) of Çorlu district of Tekirdağ province, in Turkey. Participants: The study included patients (n = 1.506) who had a positive PCR test for Covid-19 from March to September 2020. And we asked them their initial symptoms which bring them to the family medicine centers before the test. Main measurements: The participants’ age, gender, presence of chronic disease, and initial symptoms which they come to a healthcare facility were evaluated. These variables were analyzed in terms of length of hospital stay, intensive care unit admission and mortality rates. Results: The most common initial symptom in Covid-19 patients was cough. The presence of a chronic disease, the shortness of breath, malaise, the loss of smell and taste, and vomiting were found to be associated with an increased mortality rate. Advanced age, the presence of cough, malaise, the loss of smell and taste, and vomiting as the initial symptoms were found to have increased the likelihood of being admitted to the intensive care unit. Conclusions: The authors advise placing more attention on the initial symptoms of cough, malaise, the loss of smell and taste and vomiting in Covid-19 patients. Because these symptoms are related with severe prognosis indicators. Resumen: Objetivo: Describir los síntomas iniciales más relacionados con el pronóstico de COVID-19. Diseño: Este es un estudio retrospectivo de análisis de datos transversales, cuantificativos. Emplazamiento: Este estudio se realizó en los centros de medicina familiar (n = 82) del distrito de Çorlu de la proviencia de Tekirdağ, en Turquía. Participantes: El estudio incluyó pacientes (n = 1.506) que tuvieron una prueba de PCR positiva para COVID-19 de marzo a septiembre de 2020. Se les preguntaron sus síntomas iniciales que los llevan a los centros de medicina familiar antes de la prueba. Mediciones principales: Se evaluaron la edad, el sexo, la presencia de enfermedad crónica y los síntomas iniciales de los participantes que llegaron a un centro de atención médica. Estas variables se analizaron en términos de duración de la estancia hospitalaria, ingreso a la unidad de cuidados intensivos y tasas de mortalidad. Resultados: El síntoma inicial de presentación más común en los pacientes con COVID-19 fue la tos. La presencia de una enfermedad crónica, la falta de aliento, el malestar, la pérdida de olor y sabor y los vómitos se asociaron a una mayor tasa de mortalidad. La edad avanzada, la presencia de tos, malestar, la pérdida de olor y sabor, y vómitos fueron los síntomas iniciales que se encontraron para incrementar la probabilidad de ser admitido en la unidad de cuidados intensivos. Conclusiones: Los autores aconsejan prestar más atención a los síntomas iniciales de tos, malestar, pérdida de olor y sabor y vómitos en pacientes con COVID-19, porque estos síntomas están relacionados con indicadores de pronóstico severo.

Background Previous studies showed that recovered coronavirus disease 2019 (COVID-19) patients can have a subsequent positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after they are discharged from the hospital. Understanding the epidemiological characteristics of recovered COVID-19 patients who have a re-positive test is vital for preventing a second wave of COVID-19. Methods This retrospective study analyzed the epidemiological and clinical features of 20,280 COVID-19 patients from multiple centers in Wuhan who had a positive PCR test between December 31, 2019, and August 4, 2020. The RT-PCR test results for 4079 individuals who had close contact with the re-positive cases were also obtained. Results In total, 2466 (12.16%) of the 20,280 patients had a re-positive SARS-CoV-2 PCR test after they were discharged from the hospital, and 4079 individuals had close contact with members of this patient group. All of these 4079 individuals had a negative SARS-CoV-2 PCR test. Conclusions This retrospective study in Wuhan analyzed the basic characteristics of recovered COVID-19 patients with re-positive PCR test and found that these cases may not be infectious.

Highlights • In the literature, the additional contribution of a second PCR test to the diagnosis is unknown. • Performing a second nasopharyngeal test causes the excessive use of tests and personal protective equipment, the loss of labor and time, and can be costly. • A second PCR test was performed in 91.6% the patients whose first tests were negative. Of them, only 6.6% were detected positive. • The strategy of using the second nasopharyngeal PCR test to confirm or exclude the diagnosis should be reconsidered, because its additional contribution to the first test is very low., Objective The World Health Organization (WHO) recommends performing a second test in patients with a high suspicion of novel coronavirus disease (COVID-19) whose first PCR test is negative. However, the additional contribution of the second PCR test to the diagnosis is unknown. Patients and methods In this study, we aimed to investigate the contribution of second SARS-CoV-2 PCR to diagnosis in patients with a suspicion of COVID-19 whose initial test was negative. Results A total of 1449 patients were hospitalized in infectious disease clinics with the suspicion of COVID-19 infection during the study period. We performed the second PCR test (697 nasopharyngeal sample, 5 tracheal aspirate) in 702/766 (91.6%) patients whose first tests were negative and only 6.6% (46) of them were positive. Conclusions The strategy of using the second nasopharyngeal PCR test to confirm or exclude the diagnosis seems to cause the loss of labor and time, and is costly, because its additional contribution to the first test is very low.

The aim of the study was to compare the performance of various computed tomography (CT) reporting tools, including zonal CT visual score (ZCVS), the number of involved lobes, and Radiological Society of North America (RSNA) categorization in predicting adverse outcomes among patients hospitalized due to the lower respiratory symptoms during the coronavirus disease 2019 (COVID-19) pandemic. A total of 405 patients admitted with severe respiratory symptoms who underwent a chest CT were enrolled. The primary adverse outcome was intensive care unit (ICU) admission of patients. Predictive performances of reporting tools were compared using the area under the receiver operating characteristic curves (AUC ROC). Among the 405 patients, 39 (9.63%) required ICU support during their hospital stay. At least two or more observers reported a typical and indeterminate COVID-19 pneumonia CT pattern according to RSNA categorization in 70% (285/405) of patients. Among these, 63% (179/285) had a positive polymerase chain reaction (PCR test for the SARS-CoV-2 virus. The median number of lobes involved according to CT was higher in patients who required ICU support (median interquartile range [IQR], 5[3; 5] vs. 3[0; 5]). The median ZCVS score was higher among the patients that subsequently required ICU support (median [IQR], 4[0; 12] vs. 13[5.75; 24]). The bootstrap comparisons of AUC ROC showed significant differences between reporting tools, and the ZCVS was found to be superior (AUC ROC, 71-75%). The ZCVS score at the first admission showed a linear and significant association with adverse outcomes among patients with the lower respiratory tract symptoms during the COVID-19 pandemic.

Seroprevalence survey, for antibodies to SARS-CoV-2, of healthcare workers (HCW) working in three Government run hospitals in Mumbai was carried out in June 2020. Among the 801 HCWs tested, seroprevalence was 11.1%. Males (13.5% vs. 8.9% in females) and ancillary workers (18.5% vs 6.9% in doctors and nurses) were more likely to be seropositive. Sixty-two (7.74%) had been previously diagnosed with RT PCR test for SARS-CoV-2. Of these, 44 (71%) were seronegative. Upto 28 days after a positive PCR test, 90% of subjects were found to be seropositive. This reduced to less than half (38.5%) between 29 and 42 days. None of 28 infected HCWs who had the RT-PCR more than 50 days ago tested positive for antibodies. It seems likely that cellular immunity plays a larger role in defence against the illness.

CASE REPORT OF COVID 19—Recurrence We describe as case series of 7 patients who presented with a recurrence of COVID 19 by PCR test an average of 94.9 days after their initial symptomatic presentation of illness. Patients had tested negative by PCR or had evidence of antibodies in between the 2 episodes. The majority of patients were asymptomatic on the second presentation and were found incidentally on prescreen for procedures, surgery. The subsequent positive COVID-19 PCR tests resulted in cancellations of clinic, procedures, surgery, and impacted patients’ home and employment status. Further studies are needed to understand the mechanisms and ultimate outcomes of these recurrences.

In diphtheria laboratory examinations, the PCR test can be applied to isolates and clinical specimens. This study aimed to develop a PCR assay to identify the species and toxigenicity of diphtheria-causing bacteria, including the prediction of some NTTB types. Seven reference isolates, four synthetic DNA samples, 36 stored isolates, and 487 clinical samples used for PCR optimization. The PCR results was confirmed by DNA sequence analysis. The results of the PCR examination of the 7 reference isolates and 36 stored isolates were similar to the results obtained using conventional methods as gold standard, both for diphtheria-causing and non-diphtheria-causing bacteria. The validation of the PCR results using DNA sequence analysis showed that there was no mispriming or misamplification. The multiplex PCR assay developed in this study could correctly identify the species and toxigenicity of diphtheria-causing bacteria, including the prediction of some NTTB types not yet covered by established PCR methods.

Aims The impact of ongoing PCR positivity on COVID‐19 patients and the strategy and period of isolation were not fully understood. We aimed to investigate the factors that cause prolonged PCR positivity and its clinical impact on COVID‐19 infection. In addition, we searched for an answer on what length of time would be best for isolation. Methods Patients with confirmed COVID‐19 infection were included in this retrospective study. Patients with PCR positivity (after symptom onset) longer than 14 days and PCR positivity less than 14 days were compared. The relationship between duration of symptoms and PCR negation time was examined. Results A total of 339 patients were included in this study. Fifty (14%) patients had prolonged PCR positivity after 14 days. Demographic and clinical features, and clinical outcomes (disease severity and mortality) were similar among the two groups. Age (p 0.035) and symptom duration at admission (P

Background Studies of outpatients with mild or moderate COVID-19 are uncommon. We studied: 1) association of symptoms with reverse transcriptase polymerase chain reaction (RT-PCR) test results; and 2) association of initial RT-PCR cycle threshold (Ct) in relation to duration of RT-PCR positivity in outpatients with mild or moderate COVID-19. Methods This was a cohort study of outpatients with confirmed COVID-19 and at least one symptom. Participants had repeat nasopharyngeal swabs and symptom checklists every 3–5 days until two consecutive RT-PCR tests were negative. RT-PCR tests were used to assess viral load. Antibody tests for COVID-19 were performed at 2 weeks, 4 weeks, and 8 weeks after symptom onset. Results Twenty-five patients (nine females) were enrolled, ranging in age from 19–58 (median age 28 years). All patients reported at least one symptom, with a median of six symptoms per patient. Symptoms persisted for 6–67 days (median duration 18 days). In all 25 patients, blood samples collected a median of 13 days after symptom onset were positive for SARS-CoV-2 antibodies in 15 (60%). After a median of 28 days following symptom onset, 23/23 patients with available samples tested positive for antibodies. The longest duration of positive RT-PCR test was 49 days from first positive PCR test (Mean = 27.4, SD = 12.5, Median = 24). Initial Ct was significantly associated with longer duration (β = -1.3, SE = 0.3, p Conclusions In mildly or moderately ill COVID-19 outpatients, RT-PCT tests remained positive for as long as 49 days and test positivity and symptom duration correlated with initial viral load.

Background To mitigate SARS-CoV-2 transmission risks from international air travellers, many countries implemented a combination of up to 14 days of self-quarantine upon arrival plus PCR testing in the early stages of the COVID-19 pandemic in 2020. Aim To assess the effectiveness of quarantine and testing of international travellers to reduce risk of onward SARS-CoV-2 transmission into a destination country in the pre-COVID-19 vaccination era. Methods We used a simulation model of air travellers arriving in the United Kingdom from the European Union or the United States, incorporating timing of infection stages while varying quarantine duration and timing and number of PCR tests. Results Quarantine upon arrival with a PCR test on day 7 plus a 1-day delay for results can reduce the number of infectious arriving travellers released into the community by a median 94% (95% uncertainty interval (UI): 89–98) compared with a no quarantine/no test scenario. This reduction is similar to that achieved by a 14-day quarantine period (median > 99%; 95% UI: 98–100). Even shorter quarantine periods can prevent a substantial amount of transmission; all strategies in which travellers spend at least 5 days (mean incubation period) in quarantine and have at least one negative test before release are highly effective (median reduction 89%; 95% UI: 83–95)). Conclusion The effect of different screening strategies impacts asymptomatic and symptomatic individuals differently. The choice of an optimal quarantine and testing strategy for unvaccinated air travellers may vary based on the number of possible imported infections relative to domestic incidence.