Identification and Localization of COVID-19Abnormalities on Chest Radiographs using Computer Vision

The Corona Virus (COVID 19) pandemic is quickly becoming the world's most deadly disease. The spreading rate is higher and the early detection helps in faster recovery. The existence of COVID 19 in individuals shall be detected using molecular analysis or through radiographs of lungs. As time and test kit are limited RT- PCR is not suitable to test all. The RT- PCR being a time-consuming process, diagnosis using chest radiographs needs no transportation as the modern X-ray systems are digitized. Deep learning takes an edge over other techniques as it deduces the features automatically and performs massively parallel computations. Multiple feature maps will help in accurate prediction. The objective of the proposed work is to develop a Computer Aided Deep Learning System identify and localize COVID-19 virus from other viruses and pneumonia. It helps to detect COVID-19 within a short period of time thereby improving the lifetime of the individuals. SIIM-FISABIO-RSNA benchmark datasets are used to examine the proposed system. Recall, Precision, Accuracy-rate, and F-Measure are the metrics used to prove the integrity of the system. © 2023 IEEE.

Strategies for Safely Maintaining Surgical Volume During the COVID-19 Pandemic: A Mixed-Methods Study.

Resuming elective surgeries that were canceled during the COVID-19 pandemic necessitated a change to preprocedure patient preparation at a pediatric tertiary care center in middle Tennessee. We conducted a prospective, observational, mixed-methods study to determine the effectiveness of a preprocedure COVID-19 testing team to prevent COVID-19-related cancellations among pediatric patients receiving planned anesthesia. The intervention involved family member and patient education and a change in health record reporting to include COVID-19 test results. A team tasked with follow-up reviewed test results, consulted with families, and coordinated the administration of rapid tests if necessary. We compared preimplementation and postimplementation cancellation rates in four procedural areas and found no significant difference in the cancellation or rescheduling rates (P = .89, 95% confidence interval = -4.29 to 3.09). The team-based intervention was associated with the preservation of low procedural cancellation rates by mitigating barriers to preprocedural testing.

A CENTRIFUGAL MICROFLUIDIC METHOD FOR ENRICHMENT AND ENZYMATIC EXTRACTION OF SARS-COV-2 RNA FROM CLINICAL SAMPLES

The requirement for diversification of methods for sample preparation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is increasingly important to circumvent analysis bottlenecks and continue widespread surveillance testing. We report a centrifugally-driven microfluidic platform for automated affinity nanoparticle enrichment and enzymatic RNA extraction of SARS-CoV-2. The microfluidic disc (μCD) and accompanying mechatronic system(s) are capable of sample preparation from up to six patient samples simultaneously and under 20 minutes. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

Resumption of professional football league with spectators during the COVID-19 pandemic: The implementation of Bio-secure bubble protocol.

BACKGROUND: Elite professional sports events involving mass gatherings carry a high risk of viral transmission during the coronavirus disease of 2019 (COVID-19) pandemic. We describe the potential impact of resuming professional football leagues involving international participants adhering to a strict Bio-secure bubble protocol and investigate the consequences of spectators/fan attendance at such mass events during the ongoing COVID-19 pandemic in Qatar. METHODS: We conducted a descriptive cohort study involving football players, referees, match officials, local organizing committee (LOC) members, hotel and security staff working in close coordination, and over 10,000 spectators from the Asian Football Confederation (AFC) Champions League (East) and the final match. The study covered almost four weeks of the event (November 19 to December 19, 2020) under a robust Bio-secure bubble protocol. It included extensive severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RT-PCR (reverse transcription-polymerase chain reaction) every 3-6 days and clinical symptom monitoring on and off the field. Target variables included positive RT-PCR results and clinical symptom monitoring among participants, and rapid antigen testing for fan attendance to examine their safe return to the stadiums. RESULTS: A total of 12,250 RT-PCR tests involving 3158 individuals in the Bio-secure bubble were done over one month for all the AFC (East) matches, including the final match. Overall, 44 matches involving 16 teams were played. During the championship, only five individuals (three LOC members and two match officials) returned positive for COVID-19 infections. Four individuals (three team staff/officials and one person outside the Bio-secure bubble) had reactive results. None of the players tested positive for COVID-19 infection. All individuals testing positive were asymptomatic or had mild symptoms, with no one requiring hospitalization other than symptomatic treatment. The overall positivity rate was 0.15% for the entire duration of the AFC (East) Champions League. For the final match, a total of 10,320 rapid antigen tests were done for spectators, of which only one test was positive for COVID-19. CONCLUSIONS: This report shows a very low incidence rate of COVID-19 infections during mass gathering events at the international level. For the resumption of football with spectators, careful mitigation strategies should be considered to reduce the risk of transmission to a sufficiently safe level. This may require proper coordination and measures (i.e., physical distancing, testing, entry, and exit routes in the stadium, and seating arrangement inside the stadium with limited attendance). Based on this, during the ongoing COVID-19 pandemic, the supervised and controlled resumption of football matches with spectators can be done safely provided that a strict Bio-secure bubble protocol has been implemented.

Variable levels of spike and ORF1ab RNA in post-mortem lung samples of SARS-CoV-2-positive subjects: comparison between ISH and RT-PCR.

Post-mortem examination plays a pivotal role in understanding the pathobiology of the SARS-CoV-2; thus, the optimization of virus detection on the post-mortem formalin-fixed paraffin-embedded (FFPE) tissue is needed. Different techniques are available for the identification of the SARS-CoV-2, including reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. The main goal of this study is to compare ISH versus RT-PCR to detect SARS-CoV-2 on post-mortem lung samples of positive deceased subjects. A total of 27 samples were analyzed by RT-PCR targeting different viral RNA sequences of SARS-CoV-2, including envelope (E), nucleocapsid (N), spike (S), and open reading frame (ORF1ab) genes and ISH targeting S and Orf1ab. All 27 cases showed the N gene amplification, 22 out of 27 the E gene amplification, 26 out of 27 the S gene amplification, and only 6 the ORF1ab gene amplification. The S ISH was positive only in 12 out of 26 cases positive by RT-PCR. The S ISH positive cases with strong and diffuse staining showed a correlation with low values of the number of the amplification cycles by S RT-PCR suggesting that ISH is a sensitive assay mainly in cases carrying high levels of S RNA. In conclusion, our findings demonstrated that ISH assay has lower sensitivity to detect SARS-CoV-2 in FFPE compared to RT-PCR; however, it is able to localize the virus in the cellular context since it preserves the morphology.

Routine SARS-CoV-2 RT-PCR testing before digestive endoscopy during the peak of the pandemic - a single tertiary center experience.

BACKGROUND AND AIMS: COVID-19 pandemic has impacted on all endoscopy centers in the Czech Republic, that belongs to the most affected countries in the world. The aim of our study was to analyze all procedures following routine RT-PCR testing in our tertiary center during the peak of the pandemic. METHODS: We retrospectively analyzed all procedures performed from October 2020 to January 2021 after a new RT-PCR center had been set up. Main outcomes were type of scheduled procedure, indication, rate of therapeutic interventions and rate of new relevant and malignant findings. Comparison to the same period before the pandemic and SARS-CoV-2 infection in endoscopy staff are also reported. RESULTS: A total of 1,953 procedures were performed. 624 patients were referred with a negative RT-PCR test and the remaining 1,346 patients were tested in the new center. 1,293 negative tests led to 1,329 procedures. A new relevant finding was reported in 589 (44.3%), including new malignancy in 56 (4.2%). 53 patients tested positive (3.9%). There was a reduction by 9% in the number of all procedures compared to the same period before the pandemic and an increase in the number of screening colonoscopies and ERCP procedures. In the study period, 9 of 54 staff members contracted SARS-CoV-2 infection. CONCLUSIONS: Routine RT-PCR testing of patients scheduled for elective endoscopy during the peak of COVID-19 pandemic enabled us to essentially maintain our unit productivity, including activities such as screening colonoscopy, endoscopic resection and pancreatobiliary endoscopy.

A mask-based diagnostic platform for point-of-care screening of Covid-19.

Diagnostics of SARS-CoV-2 infection using real-time reverse-transcription polymerase chain reaction (RT-PCR) on nasopharyngeal swabs is now well-established, with saliva-based testing being lately more widely implemented for being more adapted for self-testing approaches. In this study, we introduce a different concept based on exhaled breath condensate (EBC), readily collected by a mask-based sampling device, and detection with an electrochemical biosensor with a modular architecture that enables fast and specific detection and quantification of COVID-19. The face mask forms an exhaled breath vapor containment volume to hold the exhaled breath vapor in proximity to the EBC collector to enable a condensate-forming surface, cooled by a thermal mass, to coalesce the exhaled breath into a 200-500 µL fluid sample in 2 min. EBC RT-PCR for SARS-CoV-2 genes (E, ORF1ab) on samples collected from 7 SARS-CoV-2 positive and 7 SARS-CoV-2 negative patients were performed. The presence of SARS-CoV-2 could be detected in 5 out of 7 SARS-CoV-2 positive patients. Furthermore, the EBC samples were screened on an electrochemical aptamer biosensor, which detects SARS-CoV-2 viral particles down to 10 pfu mL-1 in cultured SARS-CoV-2 suspensions. Using a "turn off" assay via ferrocenemethanol redox mediator, results about the infectivity state of the patient are obtained in 10 min.

Sinonasal manifestations and dynamic profile of RT-PCR results for SARS-CoV-2 in COVID-19 patients.

BACKGROUND: Sinonasal symptoms were usually reported to appear initially, yielding the symptoms important for the early detection of coronavirus disease 2019 (COVID-19). This study was conducted retrospectively to investigate the detailed sinonasal manifestations and dynamic profile of real-time reverse transcription polymerase chain reaction (RT-PCR) results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in COVID-19 patients longitudinally. METHODS: This retrospective study included 11 consecutive patients. The prevalence, timing and severity of sinonasal manifestations were analyzed. Oropharyngeal, nasal, sputum and stool specimens were collected to detect RT-PCR for SARS-CoV-2 over COVID-19 period. RESULTS: Among the 11 patients, 6 (54.5%) were female, and the median age was 51 (IQR, 36-62) years. Seven patients (63.6%) experienced sinonasal symptoms, with 6 (54.5%) exhibiting sinonasal symptoms on the onset day. Seven patients (63.6%) demonstrated nasal obstruction, 5 (45.5%) had rhinorrhea, and 4 (36.4%) exhibited olfactory dysfunction. All six patients with sinonasal symptoms on the onset day had non-severe infections. Most patients (85.7%) with sinonasal symptoms had non-severe infections. Sinonasal symptoms commonly appeared early. The positive RT-PCR rate for SARS-CoV-2 in various specimens was highest in the first week (73.3%), then gradually decreased over the disease course, but 3 patients (27.3%) had experienced a long-lasting fluctuated positive RT-PCR results since 29 days of illness in both groups, especially for two patients with airway comorbidities. CONCLUSIONS: Sinonasal symptoms were more prevalent in patients with mild or moderate COVID-19 and usually appeared early. In addition, regular nucleic acid testing for SARS-CoV-2 should be considered for COVID-19 patients with certain airway comorbidities.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) universal screening in gravids during labor and delivery.

OBJECTIVE: To screen pregnant women at risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during delivery using reverse-transcription polymerase chain reaction (RT-PCR) test and serum immunoglobulin (Ig) testing. METHOD: Between March 31 st and August 31 st of 2020, consecutive pregnant women admitted for labor and delivery in a single hospital were screened for SARS-CoV-2 with nasopharyngeal RT-PCR swab tests and detection of serum IgG and IgM. RESULTS: We studied 266 pregnant women admitted for labor and delivery. The prevalence of acute or past SARS-CoV-2 infection was 9.0 %, including (i) two cases with respiratory symptoms of SARS-Co-V-2 infection and positive RT-PCR; (ii) four asymptomatic women with positive RT-PCR without clinical symptoms and negative serological tests between two and 15 weeks later; and (iii) two women with false positive RT-PCR due to technical problems. All newborns of the 6 pregnant women with RT-PCR positive had negative RT-PCR and did not require Neonatal Intensive Care Unit admission. There were eighteen asymptomatic women with positive serological IgG tests and negative RT-PCR. CONCLUSION: In our cohort of gravids, we found 2.2 % of women with positive RT-PRC tests and 6.7 % with positive serological tests during the first wave of the SARS-CoV-2 pandemic.

Predictors of SARS-CoV-2 Positivity Based on RT-PCR Swab Tests at a Drive-Through Outpatient Clinic for COVID-19 Screening in Japan.

In response to the COVID-19 pandemic caused by SARS-CoV-2 in 2020, we conducted drive-through nasopharyngeal swab testing for COVID-19 in Sendai city, Japan, since April 2020. All tested individuals were judged in advance by public health centers for the necessity of undergoing the test with possible contact history and/or symptoms suggestive of COVID-19. In this study, to identify the predictors of SARS-CoV-2 test positivity for more efficient and evidenced selection of suspected individuals, we enrolled 3,540 consecutive individuals, tested in the first 7 months of the testing program, with data regarding to the history of close contact with COVID-19 patients, including those involved in cluster outbreaks. This cohort included 284 foreign students (257 males and 27 females) from a vocational school involved in the largest cluster outbreak in the area. Close contact history was present in 952 (26.9%) of the participants. The reverse transcription-polymerase chain reaction (RT-PCR) test results showed that 164 participants (4.6%) were positive and 3,376 participants (95.4%) were negative for the SARS-CoV-2 nucleocapsid gene (N2). In the univariate and multivariate analyses, history of close contact with COVID-19 patients, higher age, cough symptoms, and non-native ethnicity were predictors for SARS-CoV-2 test positivity. However, the significance of age and foreign nationality disappeared or declined upon excluding the foreign students from the aforementioned largest cluster outbreak. In conclusion, a history of close contact with COVID-19 patients and the presence of cough symptoms are significant predictors of SARS-CoV-2 test positivity.

Clinical Performance of the Point-of-Care cobas Liat for Detection of SARS-CoV-2 in 20 Minutes: a Multicenter Study.

Highly accurate testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the point of care (POC) is an unmet diagnostic need in emergency care and time-sensitive outpatient care settings. Reverse transcription-PCR (RT-PCR) technology is the gold standard for SARS-CoV-2 diagnostics. We performed a multisite U.S. study comparing the clinical performance of the first U.S. Food and Drug Administration (FDA)-authorized POC RT-PCR for detection of SARS-CoV-2 in 20 min, the cobas Liat SARS-CoV-2 and influenza A/B nucleic acid test, to the most widely used RT-PCR laboratory test, the cobas 68/8800 SARS-CoV-2 test. Clinical nasopharyngeal swab specimens from 444 patients with 357 evaluable specimens at five U.S. clinical laboratories were enrolled from 21 September 2020 to 23 October 2020. The overall agreement between the Liat and 68/8800 systems for SARS-CoV-2 diagnostics was 98.6% (352/357). Using Liat, positive percent agreement for SARS-CoV-2 was 100% (162/162) and the negative percent agreement was 97.4% (190/195). The Liat is an RT-PCR POC test that provides highly accurate SARS-CoV-2 results in 20 min with performance equivalent to that of high-throughput laboratory molecular testing. Rapid RT-PCR testing at the POC can enable more timely infection control and individual care decisions for coronavirus disease 2019.

Laboratory-Based Resources for COVID-19 Diagnostics: Traditional Tools and Novel Technologies. A Perspective of Personalized Medicine.

The coronavirus infection 2019 (COVID-19) pandemic, caused by the highly contagious SARS-CoV-2 virus, has provoked a global healthcare and economic crisis. The control over the spread of the disease requires an efficient and scalable laboratory-based strategy for testing the population based on multiple platforms to provide rapid and accurate diagnosis. With the onset of the pandemic, the reverse transcription polymerase chain reaction (RT-PCR) method has become a standard diagnostic tool, which has received wide clinical use. In large-scale and repeated examinations, these tests can identify infected patients with COVID-19, with their accuracy, however, dependent on many factors, while the entire process takes up to 6-8 h. Here we also describe a number of serological systems for detecting antibodies against SARS-CoV-2. These are used to assess the level of population immunity in various categories of people, as well as for retrospective diagnosis of asymptomatic and mild COVID-19 in patients. However, the widespread use of traditional diagnostic tools in the context of the rapid spread of COVID-19 is hampered by a number of limitations. Therefore, the sharp increase in the number of patients with COVID-19 necessitates creation of new rapid, inexpensive, sensitive, and specific tests. In this regard, we focus on new laboratory technologies such as loop mediated isothermal amplification (LAMP) and lateral flow immunoassay (LFIA), which have proven to work well in the COVID-19 diagnostics and can become a worthy alternative to traditional laboratory-based diagnostics resources. To cope with the COVID-19 pandemic, the healthcare system requires a combination of various types of laboratory diagnostic testing techniques, whodse sensitivity and specificity increases with the progress in the SARS-CoV-2 research. The testing strategy should be designed in such a way to provide, depending on the timing of examination and the severity of the infection in patients, large-scale and repeated examinations based on the principle: screening-monitoring-control. The search and development of new methods for rapid diagnostics of COVID-19 in laboratory, based on new analytical platforms, is still a highly important and urgent healthcare issue. In the final part of the review, special emphasis is made on the relevance of the concept of personalized medicine to combat the COVID-19 pandemic in the light of the recent studies carried out to identify the causes of variation in individual susceptibility to SARS-CoV-2 and increase the efficiency and cost-effectiveness of treatment.

COVID-19 diagnostic laboratory strategies: modern technologies and development trends (review of literature).

The COVID-19 pandemic, associated with the new coronavirus SARS-CoV-2, has caused a surge in incidence worldwide, as well as a severe crisis in global health and economy. Therefore, fast and accurate diagnosis of infection is key to timely treatment and elimination of the spread of the virus. Currently, the standard method for detecting coronavirus is reverse transcription polymerase chain reaction (RT-PCR). However, this method requires expensive equipment and trained personnel, which limits the conduct of mass testing and lengthens the time to obtain a research result. Serological tests for antibodies against SARS-CoV-2 and the determination of protective immunity in various populations are used to retrospectively identify patients with asymptomatic and mild forms of infection, monitor the course of infection in hospitalized patients, and also track contacts and epidemiological surveillance. The use of standard methods for diagnosing COVID-19 in conditions of mass morbidity, especially in conditions of insufficient resources and lack of appropriate infrastructure, is associated with a number of limitations. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. The review examines new laboratory technologies for diagnosing a new infection - loop isothermal amplification (LAMP) and immunochromatographic analysis (ICA), which can become a real alternative to the used molecular and enzyme immunoassay methods. The dynamic development of these methods in recent years expands the prospects for their use both for diagnosing COVID-19 and monitoring a pandemic.

Profile of Patients Suspected to be COVID-19: A Retrospective Analysis of Early Pandemic Data.

Background and Objectives Coronavirus disease 2019 (COVID-19), a global public health emergency of profound magnitude, has brought life to an unprecedented near-standstill. The clinical profile of the disease is still emerging and is marked by considerable geographical variability in terms of transmissibility, clinical profile, virulence, and mortality of the disease. As clinical data is being reported from around the globe, it becomes important to focus on local subjects in a global milieu, lest one misses the trees for the forest. Our study is a short retrospective analysis of the demographic and clinical profiles of subjects presenting with a mild flu-like illness to our hospital who were tested for COVID-19. It compares the differences in age and sex of those who tested positive with those negative. In addition, it reviews the length of time it might take for a case testing positive on reverse transcriptase-polymerase chain reaction (RT-PCR) test to become negative. Methodology A retrospective analysis of data from adults who presented to our hospital with a mild flu-like illness between the months of March and May 2020 was conducted to understand the disease profile. The nasal/oropharyngeal swabs were collected from each patient and were transported to state-approved laboratories chain for RT-PCR analysis. Information was collected from reports received, clinical information forms, and sample collection forms that were being maintained as a part of the clinical management protocol. Data were analysed using Stata software, version 13 (StataCorp LLC, College Station, TX, USA). Observations and Results Three thousand twenty-six subjects presented to our hospital with either mild flu-like symptoms or with suspected exposure to a confirmed case of COVID-19. The subjects had a mean age of 37.3 (± 15.1) years and 1,805 (60.3%) were males. A regression analysis revealed an adjusted odds of 1.6 (95% confidence interval (CI): 1.2, 2.1) for testing positive for males as compared to females. For every one year increase in age, the odds for testing positive increased by 1.02 (95% CI: 1.01, 1.03). Of the 2,592 individuals for whom data was available, 201 (7.6%) were found positive on RT-PCR analysis. Those testing positive were significantly older (41.0 years vs 36.8 years; p = 0.001) and more likely to be male (number: 138; 9.0% vs 6.7%; p = 0.05). Cough, followed by fever, was a common presenting feature. A survival time analysis using data from 54 participants documented 455 days of the total observation period. A median time of eight days was required for the test to convert from positive to negative if the patient remained mildly symptomatic and did not develop a severe complicated illness. The time to conversion did not differ with age or sex. Conclusions Our analysis shows that patients with COVID-19 have presented with milder symptoms and have recovered well. The low test positivity rate is indicative of the early phase of the pandemic in the country and is a reflection of active infection control measures.

Vital role of chest CT in diagnosis of coronavirus disease 2019 (COVID-19).

In December 2019, a new virus called coronavirus disease 2019 (COVID-19) causing severe acute respiratory syndrome emerged in Wuhan, China, and rapidly spread to other areas of China and other regions of the world. Since it was a discovery, COVID-19 has spread to several countries and to this date, affecting about 2,329,651 people and caused about 160,721 deaths. Since most COVID-19 infected cases were diagnosed with pneumonia and characteristic chest computed tomography (CT) scan patterns, radiological examinations have become an important tool in early diagnosis. Nowadays, CT findings combined with normal blood cells (WBCs), lymphopenia and a history of epidemiological exposure have been used as criteria for clinical diagnosis of COVID-19. It is noteworthy that reverse transcription polymerase chain reaction (RT-PCR) test is still gold standard for the diagnosis. This review focuses on role of chest CT in the clinical evaluation of disease progression and more accurate diagnosis.

Monitoring of viral load by RT-PCR caused decision making to continue ECMO therapy for a patient with COVID-19.

Most patients with coronavirus disease 2019 (COVID-19) have just only mild symptoms, but about 5% are very severe. Although extracorporeal membranous oxygenation (ECMO) is sometimes used in critically patients with COVID-19, ECMO is only an adjunct, not the main treatment. If the patient's condition deteriorates and it is determined to be irreversible, it is necessary to decide to stop ECMO. A 54-year-old man was admitted on day 6 of onset with a chief complaint of high fever and cough. Computed tomography (CT) showed a ground glass opacity in both lungs, and reverse transcription-polymerase chain reaction (RT-PCR) diagnosed COVID-19. He was admitted to the hospital and started to receive oxygen and favipiravir. After that, his respiratory condition deteriorated, and he was intubated and ventilated on day 9 of onset, and ECMO was introduced on day 12. Two days after the introduction of ECMO, C-reactive protein (CRP) increased, chest X-p showed no improvement in pneumonia, and PaO2/FiO2 decreased again. As D-dimer rose and found a blood clot in the ECMO circuit, we had to decide whether to replace the circuit and continue with ECMO or stop ECMO. At this time, the viral load by RT-PCR was drastically reduced to about 1/1750. We decided to continue ECMO therapy and replaced the circuit. The patient's respiratory status subsequently improved and ECMO was stopped on day 21 of onset. In conclusion, viral load measurement by RT-PCR may be one of the indicators for promoting the treatment of severe COVID-19 patients.

Chest CT for triage during COVID-19 on the emergency department: myth or truth?

PURPOSE: We aimed to investigate the diagnostic performance of chest CT compared with first RT-PCR results in adult patients suspected of COVID-19 infection in an ED setting. We also constructed a predictive machine learning model based on chest CT and additional data to improve the diagnostic accuracy of chest CT. METHODS: This study's cohort consisted of 319 patients who underwent chest CT and RT-PCR testing at the ED. Patient characteristics, demographics, symptoms, vital signs, laboratory tests, and chest CT results (CO-RADS) were collected. With first RT-PCR as reference standard, the diagnostic performance of chest CT using the CO-RADS score was assessed. Additionally, a predictive machine learning model was constructed using logistic regression. RESULTS: Chest CT, with first RT-PCR as a reference, had a sensitivity, specificity, PPV, and NPV of 90.2%, 88.2%, 84.5%, and 92.7%, respectively. The prediction model with CO-RADS, ferritin, leucocyte count, CK, days of complaints, and diarrhea as predictors had a sensitivity, specificity, PPV, and NPV of 89.3%, 93.4%, 90.8%, and 92.3%, respectively. CONCLUSION: Chest CT, using the CO-RADS scoring system, is a sensitive and specific method that can aid in the diagnosis of COVID-19, especially if RT-PCR tests are scarce during an outbreak. Combining a predictive machine learning model could further improve the accuracy of diagnostic chest CT for COVID-19. Further candidate predictors should be analyzed to improve our model. However, RT-PCR should remain the primary standard of testing as up to 9% of RT-PCR positive patients are not diagnosed by chest CT or our machine learning model.

Chest CT study of fifteen COVID-19 patients with positive RT-PCR retest results after discharge.

BACKGROUND: Our hospital is a designated institution for COVID-19 patients in Chengdu, China. This study aimed to analyze the clinical and chest CT features of 15 COVID-19 patients with positive reverse transcription-polymerase chain reaction (RT-PCR) retest results after discharge. Patients who met the current standards of discharge could still carry the SARS-CoV-2 virus. METHODS: Clinical manifestations, laboratory data, and chest CT images were retrospectively reviewed and analyzed. RESULTS: The most common symptoms at Covid-19COVID-19 initial onset were fever (12/15, 80%) and cough (11/15, 73.3%). Most of the patients had a normal white blood cells (12/15, 80%), neutrophils (12/15, 80%), and lymphocytes count (13/15, 86.7%); some patients had increased C-reactive protein (CRP) (5/15, 33.3%), and increased lactate dehydrogenase (LDH) (4/15, 26.7%) during first admission. Five patients (33.3%) had a cough before their first discharge. The average interval from the first discharge to re-admission was 17 days (range, 9-30 days). At re-admission, two (13.3%) patients presented with cough, and one (6.6%) had chest pain with anxiety. At re-admission, all patients had normal clinical results except five (33.3%) patients had increased CRP compared with first discharging, two (13.3%) patients had increased neutrophils count, and one (6.6%) had increased CRP. The majority of patients had normal procalcitonin. Ground glass opacities (GGOs) and reticulation in the peripheral and subpleural areas were the most common CT manifestations, and six patients (40%) showed a transformation from reticulation to GGOs when re-admitted. CONCLUSIONS: There may be no specific clinical characteristics to predict the re-detectability of the virus. A regular medical observation and a bi-monthly follow-up is recommended.

A case of imported COVID-19 diagnosed by PCR-positive lower respiratory specimen but with PCR-negative throat swabs.

A 35-year-old woman presented with fever and mild diarrhoea without any respiratory symptoms 9 days after travelling to Japan from Wuhan, China. Her computed tomography scan revealed pneumonia. The first polymerase chain reaction (PCR) test on throat swab for the novel corona virus upon admission was negative. Therefore, she was treated for community-acquired pneumonia, but fever persisted. On hospital day 5, PCR test on induced sputum was positive, but a second polymerase chain reaction test on throat swab remained negative. She was discharged, fully recovered, on hospital day 12. A lower respiratory tract specimen should be obtained for better diagnosis of corona virus disease 2019, even in the absence of respiratory symptoms for patients with significant travel or exposure history.

Pregnancy and Perinatal Outcomes of Women With Coronavirus Disease (COVID-19) Pneumonia: A Preliminary Analysis.

OBJECTIVE. The purpose of this study was to describe the clinical manifestations and CT features of coronavirus disease (COVID-19) pneumonia in 15 pregnant women and to provide some initial evidence that can be used for guiding treatment of pregnant women with COVID-19 pneumonia. MATERIALS AND METHODS. We reviewed the clinical data and CT examinations of 15 consecutive pregnant women with COVID-19 pneumonia in our hospital from January 20, 2020, to February 10, 2020. A semiquantitative CT scoring system was used to estimate pulmonary involvement and the time course of changes on chest CT. Symptoms and laboratory results were analyzed, treatment experiences were summarized, and clinical outcomes were tracked. RESULTS. Eleven patients had successful delivery (10 cesarean deliveries and one vaginal delivery) during the study period, and four patients were still pregnant (three in the second trimester and one in the third trimester) at the end of the study period. No cases of neonatal asphyxia, neonatal death, stillbirth, or abortion were reported. The most common early finding on chest CT was ground-glass opacity (GGO). With disease progression, crazy paving pattern and consolidations were seen on CT. The abnormalities showed absorptive changes at the end of the study period for all patients. The most common onset symptoms of COVID-19 pneumonia in pregnant women were fever (13/15 patients) and cough (9/15 patients). The most common abnormal laboratory finding was lymphocytopenia (12/15 patients). CT images obtained before and after delivery showed no signs of pneumonia aggravation after delivery. The four patients who were still pregnant at the end of the study period were not treated with antiviral drugs but had achieved good recovery. CONCLUSION. Pregnancy and childbirth did not aggravate the course of symptoms or CT features of COVID-19 pneumonia. All the cases of COVID-19 pneumonia in the pregnant women in our study were the mild type. All the women in this study-some of whom did not receive antiviral drugs-achieved good recovery from COVID-19 pneumonia.