Nasopharyngeal RT-PCR Research Articles

Sensitivity of Rapid Antigen Testing and RT-PCR Performed on Nasopharyngeal Swabs versus Saliva Samples in COVID-19 Hospitalized Patients: Results of a Prospective Comparative Trial (RESTART).

Saliva sampling could serve as an alternative non-invasive sample for SARS-CoV-2 diagnosis while rapid antigen tests (RATs) might help to mitigate the shortage of reagents sporadically encountered with RT-PCR. Thus, in the RESTART study we compared antigen and RT-PCR testing methods on nasopharyngeal (NP) swabs and salivary samples. We conducted a prospective observational study among COVID-19 hospitalized patients between 10 December 2020 and 1 February 2021. Paired saliva and NP samples were investigated by RT-PCR (Cobas 6800, Roche-Switzerland, Basel, Switzerland) and by two rapid antigen tests: One Step Immunoassay Exdia® COVID-19 Ag (Precision Biosensor, Daejeon, Korea) and Standard Q® COVID-19 Rapid Antigen Test (Roche-Switzerland). A total of 58 paired NP-saliva specimens were collected. A total of 32 of 58 (55%) patients were hospitalized in the intensive care unit, and the median duration of symptoms was 11 days (IQR 5-19). NP and salivary RT-PCR exhibited sensitivity of 98% and 69% respectively, whereas the specificity of these RT-PCRs assays was 100%. The NP RATs exhibited much lower diagnostic performance, with sensitivities of 35% and 41% for the Standard Q® and Exdia® assays, respectively, when a wet-swab approach was used (i.e., when the swab was diluted in the viral transport medium (VTM) before testing). The sensitivity of the dry-swab approach was slightly better (47%). These antigen tests exhibited very low sensitivity (4% and 8%) when applied to salivary swabs. Nasopharyngeal RT-PCR is the most accurate test for COVID-19 diagnosis in hospitalized patients. RT-PCR on salivary samples may be used when nasopharyngeal swabs are contraindicated. RATs are not appropriate for hospitalized patients.

Emergence of E484K Mutation Following Bamlanivimab Monotherapy among High-Risk Patients Infected with the Alpha Variant of SARS-CoV-2.

An Emergency Use Authorization was issued in the United States and in Europe for a monoclonal antibody monotherapy to prevent severe COVID-19 in high-risk patients. This study aimed to assess the risk of emergence of mutations following treatment with a single monoclonal antibody. Bamlanivimab was administered at a single dose of 700 mg in a one-hour IV injection in a referral center for the management of COVID-19 in France. Patients were closely monitored clinically and virologically with nasopharyngeal RT-PCR and viral whole genome sequencing. Six patients were treated for a nosocomial SARS-CoV-2 infection, all males, with a median age of 65 years and multiple comorbidities. All patients were infected with a B.1.1.7 variant, which was the most frequent variant in France at the time, and no patients had E484 mutations at baseline. Bamlanivimab was infused in the six patients within 4 days of the COVID-19 diagnosis. Four patients had a favorable outcome, one died of complications unrelated to COVID-19 or bamlanivimab, and one kidney transplant patient treated with belatacept died from severe COVID-19 more than 40 days after bamlanivimab administration. Virologically, four patients cleared nasopharyngeal viral shedding within one month after infusion, while two presented prolonged viral excretion for more than 40 days. The emergence of E484K mutants was observed in five out of six patients, and the last patient presented a Q496R mutation potentially associated with resistance. CONCLUSIONS: These results show a high risk of emergence of resistance mutants in COVID-19 patients treated with monoclonal antibody monotherapy.

SARS-CoV-2 Drive/Walk-Thru screening centers in Colombia: The CoVIDA project

Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model’s performance were based on international experiences and scientific literature. Two screening centers were implemented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bogotá. Low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.

Presence of SARS-CoV-2 Antibodies in Spent Peritoneal Dialysate.

Presence of SARS-CoV-2 Antibodies in Spent Peritoneal Dialysate.

Diagnostic Accuracy of SARS-CoV-2 Antigen Detection Test in Children: A Real-Life Study.

Naso-pharyngeal RT-PCR is the gold standard for the diagnosis of COVID-19, but there is a need for rapid and reliable tests. Some validation studies have used frozen aliquots mainly from adults. The aim of this real-life study was to test the performance of a SARS-CoV-2 rapid antigen test (SC2-RAT) in children. Symptomatic patients aged 0 to 17 years were recruited in the emergency department of the University Hospital of Creteil and in primary care pediatric practices from October 10, 2020 for 7 weeks. Each enrolled child had a SARS-CoV-2 RT-PCR test and a SC2-RAT from two distinct nasopharyngeal swabs. Among the 308 patients (mean [SD] age 4.9 [5.3] years), fever was the main symptom (73.4%), with no difference between COVID-19–negative and –positive groups. The prevalence of COVID-19 was 10.7% (95% CI 7.5–14.7). On the whole cohort, the sensitivity and specificity of the SC2-RAT compared to RT-PCR was 87.9% (95% CI 71.8–96.6) and 98.5% (95% CI 96.3–99.6). Considering samples with cycle threshold >25, the sensibility was lower: 63.6% (95% CI 30.8–89.1) and the specificity 99.6% (95% CI 98.0–100.0). The mean delay to obtain an SC2-RAT result was <15 min but was 3.2 h (SD 5.5) for an RT-PCR result. Contact with a COVID-19–positive person was more frequent for COVID-19–positive than –negative patients (n = 21, 61.6%, vs. n = 64, 24.6%; p < 0.01). In real life, SC2-RAT seems reliable for symptomatic children, allowing to detect contagious children.

Neumonía COVID-19: relación entre la radiografía de tórax inicial y los datos analíticos

ObjectiveTo analyze the initial findings in chest X-rays of patients with RT-PCR positive for SARS-CoV-2, and to determine whether there is a relationship between the severity of these findings and the clinical and laboratory findings. Materials and methodsThis retrospective study analyzed the relationship between initial chest X-rays and initial laboratory tests in symptomatic adults with nasopharyngeal RT-PCR results positive for SARS-CoV-2 seen at our center between February 29 and March 23, 2020. Among other radiologic findings, we analyzed ground-glass opacities, consolidations, linear opacities, and pleural effusion. We also used a scale of radiologic severity to assess the distribution and extent of these findings. Among initial laboratory findings, we analyzed leukocytes, lymphocytes, platelets, neutrophil-to-lymphocyte ratio, and C-reactive protein. ResultsOf 761 symptomatic patients, 639 (84%) required hospitalization and 122 were discharged to their homes. The need for admission increased with increasing scores on the scale of radiologic severity. The extent of initial lung involvement was significantly associated with the laboratory parameters analyzed (p<0.05 for platelets, p<0.01 for lymphocytes, and p<0.001 for the remaining parameters), as well as with the time from the onset of symptoms (p<0.001). ConclusionIt can be useful to use a scale of radiologic severity to classify chest X-ray findings in diagnosing patients with COVID-19, because the greater the radiologic severity, the greater the need for hospitalization and the greater the alteration in laboratory parameters.

Low performance of a SARS-CoV-2 point-of-care lateral flow immunoassay in symptomatic children during the pandemic

Objectiveto evaluate the accuracy of an antibody point-of-care lateral flow immunoassay (LFI - Wondfo Biotech Co., Guangzhou, China) in a pediatric population. Methodschildren and adolescents (2 months to 18 years) with signs and symptoms suggestive of acute SARS-CoV-2 infection were prospectively investigated with nasopharyngeal RT-PCR and LFI at the emergency room. RT-PCR was performed at baseline, and LFI at the same time or scheduled for those with less than 7 days of the clinical picture. Overall accuracy, sensitivity and specificity were assessed, as well as according to the onset of symptoms (7-13 or ≥14 days) at the time of the LFI test. ResultsIn 175 children included, RT-PCR and LFI were positive in 51 (29.14%) and 36 (20.57%), respectively. The overall sensitivity, specificity, positive and negative predictive value was 70.6% (95%CI 56.2-82.5), 96.8% (95%CI 91.9-99.1), 90.0% (95%CI 77.2-96.0), and 88.9% (95%CI 83.9-92.5), respectively. At 7-13 and ≥14 days after the onset of symptoms, sensitivity was 60.0% (95%CI 26.2-87.8) and 73.2% (95%CI 57.1-85.8) and specificity was 97.9% (95%CI 88.7-99.9) and 96.1% (95%CI 89.0-99.2), respectively. ConclusionDespite its high specificity, in the present study the sensitivity of LFI in children was lower (around 70%) than most reports in adults. Although a positive result is informative, a negative LFI test cannot rule out COVID-19 in children.

Safety and immunogenicity of one versus two doses of the COVID-19 vaccine BNT162b2 for patients with cancer: interim analysis of a prospective observational study

SummaryBackgroundThe efficacy and safety profiles of vaccines against SARS-CoV-2 in patients with cancer is unknown. We aimed to assess the safety and immunogenicity of the BNT162b2 (Pfizer–BioNTech) vaccine in patients with cancer.MethodsFor this prospective observational study, we recruited patients with cancer and healthy controls (mostly health-care workers) from three London hospitals between Dec 8, 2020, and Feb 18, 2021. Participants who were vaccinated between Dec 8 and Dec 29, 2020, received two 30 μg doses of BNT162b2 administered intramuscularly 21 days apart; patients vaccinated after this date received only one 30 μg dose with a planned follow-up boost at 12 weeks. Blood samples were taken before vaccination and at 3 weeks and 5 weeks after the first vaccination. Where possible, serial nasopharyngeal real-time RT-PCR (rRT-PCR) swab tests were done every 10 days or in cases of symptomatic COVID-19. The coprimary endpoints were seroconversion to SARS-CoV-2 spike (S) protein in patients with cancer following the first vaccination with the BNT162b2 vaccine and the effect of vaccine boosting after 21 days on seroconversion. All participants with available data were included in the safety and immunogenicity analyses. Ongoing follow-up is underway for further blood sampling after the delayed (12-week) vaccine boost. This study is registered with the NHS Health Research Authority and Health and Care Research Wales (REC ID 20/HRA/2031).Findings151 patients with cancer (95 patients with solid cancer and 56 patients with haematological cancer) and 54 healthy controls were enrolled. For this interim data analysis of the safety and immunogenicity of vaccinated patients with cancer, samples and data obtained up to March 19, 2021, were analysed. After exclusion of 17 patients who had been exposed to SARS-CoV-2 (detected by either antibody seroconversion or a positive rRT-PCR COVID-19 swab test) from the immunogenicity analysis, the proportion of positive anti-S IgG titres at approximately 21 days following a single vaccine inoculum across the three cohorts were 32 (94%; 95% CI 81–98) of 34 healthy controls; 21 (38%; 26–51) of 56 patients with solid cancer, and eight (18%; 10–32) of 44 patients with haematological cancer. 16 healthy controls, 25 patients with solid cancer, and six patients with haematological cancer received a second dose on day 21. Of the patients with available blood samples 2 weeks following a 21-day vaccine boost, and excluding 17 participants with evidence of previous natural SARS-CoV-2 exposure, 18 (95%; 95% CI 75–99) of 19 patients with solid cancer, 12 (100%; 76–100) of 12 healthy controls, and three (60%; 23–88) of five patients with haematological cancers were seropositive, compared with ten (30%; 17–47) of 33, 18 (86%; 65–95) of 21, and four (11%; 4–25) of 36, respectively, who did not receive a boost. The vaccine was well tolerated; no toxicities were reported in 75 (54%) of 140 patients with cancer following the first dose of BNT162b2, and in 22 (71%) of 31 patients with cancer following the second dose. Similarly, no toxicities were reported in 15 (38%) of 40 healthy controls after the first dose and in five (31%) of 16 after the second dose. Injection-site pain within 7 days following the first dose was the most commonly reported local reaction (23 [35%] of 65 patients with cancer; 12 [48%] of 25 healthy controls). No vaccine-related deaths were reported.InterpretationIn patients with cancer, one dose of the BNT162b2 vaccine yields poor efficacy. Immunogenicity increased significantly in patients with solid cancer within 2 weeks of a vaccine boost at day 21 after the first dose. These data support prioritisation of patients with cancer for an early (day 21) second dose of the BNT162b2 vaccine.FundingKing's College London, Cancer Research UK, Wellcome Trust, Rosetrees Trust, and Francis Crick Institute.

COVID-19 herd immunity by immunisation: are children in the herd?

COVID-19 herd immunity by immunisation: are children in the herd?

Prevalence of Symptoms in Patients Discharged from COVID Care Facility of NIMS Hospital: Is RT PCR Negativity Truly Reflecting Recovery? A Single-Centre Observational Study.

PurposeTo assess the prevalence of post-COVID symptoms in patients with recovered COVID-19 (nasopharyngeal RT PCR negative) who were discharged from an acute COVID care facility at a tertiary care teaching hospital in North India.MethodsThis study was an observational study with retrospective data collection, conducted in the COVID follow-up clinic, a combined clinic of medicine and endocrinology. Patients discharged from the acute COVID care facility were recruited after 14 days of discharge if they fulfilled inclusion and exclusion criteria. The retrospective data was collected from the hospital records/EMR and analysed by the SPSSv23.ResultsFifty patients, who fulfilled the inclusion and exclusion criteria, were included in the study. The Mean age of patients was 53.4±13.8 years (range 28–77). Seventy six percent were male, and 38% had type 2 diabetes. Fever (94%), cough (78%) and breathlessness (68%), were the most common symptoms at presentation to acute care facility. Oxygen saturation at presentation had a negative correlation with D-Dimer, age, and C reactive protein. When patients were evaluated clinically, after 14 days (range 15 to 50 days) of the discharge, 82% of patients had at least one persistent symptom. Fatigue (74%) was the most common symptoms in follow-up followed by breathlessness (44%), and muscle weakness (36%). Two patients had persistent fever, even after negative RT PCR status.ConclusionPatients discharged from the acute COVID care facility had a high prevalence of post-COVID symptoms even after 14 days.

Gemelli decision tree Algorithm to Predict the need for home monitoring or hospitalization of confirmed and unconfirmed COVID-19 patients (GAP-Covid19): preliminary results from a retrospective cohort study.

To develop a deep learning-based decision tree for the primary care setting, to stratify adult patients with confirmed and unconfirmed coronavirus disease 2019 (COVID-19), and to predict the need for hospitalization or home monitoring. We performed a retrospective cohort study on data from patients admitted to a COVID hospital in Rome, Italy, between 5 March 2020 and 5 June 2020. A confirmed case was defined as a patient with a positive nasopharyngeal RT-PCR test result, while an unconfirmed case had negative results on repeated swabs. Patients' medical history and clinical, laboratory and radiological findings were collected, and the dataset was used to train a predictive model for COVID-19 severity. Data of 198 patients were included in the study. Twenty-eight (14.14%) had mild disease, 62 (31.31%) had moderate disease, 64 (32.32%) had severe disease, and 44 (22.22%) had critical disease. The G2 value assessed the contribution of each collected value to decision tree building. On this basis, SpO2 (%) with a cut point at 92 was chosen for the optimal first split. Therefore, the decision tree was built using values maximizing G2 and LogWorth. After the tree was built, the correspondence between inputs and outcomes was validated. We developed a machine learning-based tool that is easy to understand and apply. It provides good discrimination in stratifying confirmed and unconfirmed COVID-19 patients with different prognoses in every context. Our tool might allow general practitioners visiting patients at home to decide whether the patient needs to be hospitalized.

A Child with Influenza A and Large Pneumatocele

: Necrotizing pneumonia (NP) is a rare complication of community-acquired pneumonia, which occurs in patients with viral pneumonia such as influenza and secondary bacterial infection. We present a five-year-old boy with cough and dyspnea and low SpO2, who was admitted to PICU. He was intubated, and two-sided chest tubes were placed because of pleural effusion. Nasopharyngeal RT-PCR for H1N1 was positive. Subcutaneous and mediastinal emphysema and a large pneumatocele developed concomitantly, and the patient underwent three times percutaneous aspiration of pneumatocele under anesthesia and CT scan guide without surgery. The size of the pneumatocele decreased, and the patient was extubated. After one month of admission, he was discharged in good condition and no pulmonary sequela.

Determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection

Objective: To evaluate determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection. Materials and methods: Hospitalized patients with SARS-CoV-2 positive nasopharyngeal RT-PCR were included in a single-center, retrospective study. Patients were divided in 2 groups according to the timing of viral clearance [≤14 days, “early clearance (EC)” and >14 days, “late clearance (LC)”]. Results: 179 patients were included in the study (101 EC, 78 LC), with median age 62 years. Median time of viral shedding was 14 days (EC/LC 10 and 19 days, respectively, P < 0.0001). Univariate analyses showed that age, male gender, receiving corticosteroids, receiving tocilizumab, ICU admission, low albumin and NLR ratio were associated with late viral clearance. In the multivariable analysis, older age (P = 0.016), albumin level (P = 0.048), corticosteroids (P = 0.021), and tocilizumab (P = 0.015) were significantly associated with late viral clearance. Conclusions: Age, albumin, tocilizumab and corticosteroid treatment were independently associated with a prolonged SARS-CoV-2 RNA shedding.

Incidence of Electrographic Seizures in Patients With COVID-19.

Critical illness and sepsis are commonly associated with subclinical seizures. COVID-19 frequently causes severe critical illness, but the incidence of electrographic seizures in patients with COVID-19 has been reported to be low. This retrospective case series assessed the incidence of and risks for electrographic seizures in patients hospitalized with COVID-19 who underwent continuous video electroencephalography monitoring (cvEEG) between March 1st, 2020 and June 30th, 2020. One hundred and twenty-two patients were initially identified who resulted SARS-CoV-2 nasopharyngeal RT-PCR swab positivity with any electroencephalography order placed in the EMR. Seventy-nine patients met study inclusion criteria: age ≥18 years, >1 h of cvEEG monitoring, and positive SARS-CoV-2 nasopharyngeal swab PCR. Six (8%) of the 79 patients suffered electrographic seizures (ES), three of whom suffered non-convulsive status epilepticus. Acute hyperkinetic movements were the most common reason for cvEEG in patients with ES (84%). None of the patients undergoing cvEEG for persistent coma (29% of all patients) had ES. Focal slowing (67 vs. 10%), sporadic interictal epileptiform discharges (EDs; 33 vs. 6%), and periodic/rhythmic EDs (67 vs. 1%) were proportionally more frequent among patients with electrographic seizures than those without these seizures. While 15% of patients without ES had generalized periodic discharges (GPDs) with triphasic morphology on EEG, none of the patients with ES had this pattern. Further study is required to assess the predictive values of these risk factors on electrographic seizure incidence and subsequent outcomes.

Sociodemographic risk factors for coronavirus disease 2019 (COVID-19) infection among Massachusetts healthcare workers: A retrospective cohort study.

To better understand coronavirus disease 2019 (COVID-19) transmission among healthcare workers (HCWs), we investigated occupational and nonoccupational risk factors associated with cumulative COVID-19 incidence among a Massachusetts HCW cohort. The retrospective cohort study included adult HCWs in a single healthcare system from March 9 to June 3, 2020. The SARS-CoV-2 nasopharyngeal RT-PCR results and demographics of the study participants were deidentified and extracted from an established occupational health, COVID-19 database at the healthcare system. HCWs from each particular job grouping had been categorized into frontline or nonfrontline workers. Incidence rate ratios (IRRs) and odds ratios (ORs) were used to compare subgroups after excluding HCWs involved in early infection clusters before universal masking began. A sensitivity analysis was performed comparing jobs with the greatest potential occupational risks with others. Of 5,177 HCWs, 152 (2.94%) were diagnosed with COVID-19. Affected HCWs resided in areas with higher community attack rates (median, 1,755.2 vs 1,412.4 cases per 100,000; P < .001; multivariate-adjusted IRR, 1.89; 95% CI, 1.03-3.44 comparing fifth to first quintile of community rates). After multivariate adjustment, African-American and Hispanic HCWs had higher incidence of COVID-19 than non-Hispanic white HCWs (IRR, 2.78; 95% CI, 1.78-4.33; and IRR, 2.41, 95% CI, 1.42-4.07, respectively). After adjusting for race and residential rates, frontline HCWs had a higher IRR (1.73, 95% CI, 1.16-2.54) than nonfrontline HCWs overall, but not within specific job categories nor when comparing the highest risk jobs to others. After universal masking was instituted, the strongest risk factors associated with HCW COVID-19 infection were residential community infection rate and race.

COVID-19 and orthopaedic surgery in a large trauma centre in India

Background: We are in the midst of a pandemic caused by the novel SARS-Cov-2 virus. A large percentage of the patients are asymptomatic and hospitals around the world are struggling to restart routine services. We report the results of a universal testing protocol of all patients who underwent orthopaedic surgery in the month of July 2020 in a large orthopaedic speciality hospital in Bangalore, India. Methods: A retrospective study of all patients who underwent orthopaedic surgery in the month of July 2020 at a tertiary care orthopaedic speciality hospital in Bangalore, India. All patients underwent nasopharyngeal swab test before surgery. A questionnaire was used to assess the patient before the RT-PCR nasopharyngeal swab test. Data regarding imaging, investigations and follow up was recorded. Results: In the month of July 2020, 168 patients underwent routine nasopharyngeal RT-PCR swab test for COVID-19 prior to planned orthopaedic surgical procedure (Both trauma and elective cases). 16 of the RT-PCR tests were positive. However vascular cases and absolute emergencies were done without a RT-PCR test with PPE and all universal precautions. 11 patients underwent emergency surgery without a RT-PCR test. All 16 cases who were positive were asymptomatic. The asymptomatic positive rate was 9.52%. Of the 11 patients who underwent emergency surgery without a RT-PCR test, only one patient had a positive test post-operatively. Conclusions: Routine nasopharyngeal RT-PCR testing revealed a high rate of asymptomatic cases. If the RT-PCR test is positive, it is best to defer the case till the test returns negative. All precautions must be taken while performing emergency surgeries. Our algorithm in managing patients has proven to be effective and can be replicated with ease to continue operating and taking care of orthopaedic patients during this pandemic.

Secondary Bacterial Organizing Pneumonia in a Patient Recovered from COVID-19 Disease: A Case Report

COVID-19 disease is a global pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) that mainly presents with pneumonia, but has variable multi-systemic manifestations. Concomitant bacterial infections associated with the acute stage of COVID-19 disease have been rarely reported in the literature. However, to our knowledge, post viral organizing pneumonia (OP) secondary to bacterial infection after recovery from SARS-CoV2 infection has not been noted before. We report a 27-year-old male patient with Type 1 Diabetes Mellitus who presented with fever post recovery from COVID-19 disease for seven weeks and was found to have OP secondary to Klebsiella pneumoniae. Furthermore, the bronchoalveolar lavage was positive for SARS-CoV2 by RT-PCR despite multiple negative nasopharyngeal RT-PCR. The patient was successfully treated with antibiotics only. Therefore, we conclude that early recognition of OP secondary to bacterial infection in patients with COVID-19 disease and prompt antibiotic treatment could avoid the use of a prolonged course of steroids.

402. Spontaneous pneumothorax in COVID-19

BackgroundPneumothorax has been reported with the use of positive pressure ventilation in COVID-19 pneumonia. Literature on spontaneous pneumothorax (PTX) in COVID-19 patients is scant. We present a case series of 7 patients with COVID-19 pneumonia, who developed spontaneous pneumothorax without prior mechanical ventilation.MethodsA retrospective chart review of 7 cases was performed from two different hospitals in the US between 4/6/2020–5/15/2020. Hospitalized patients with confirmed COVID-19 by nasopharyngeal RT-PCR who developed spontaneous pneumothorax were included. Collected data included demographics, co-morbidities, inflammatory biomarkers, chest imaging and management strategies. Length of stay, transfer to intensive care unit and death were the assessed outcomes. A descriptive analysis was done.ResultsThere were 3 patients from Henry Ford Health System, Michigan and 4 patients from Silver Cross Hospital, Illinois. Median age was 75 years and 6 out of 7 (85.7%) were males (Table 1). There were no co-morbidities associated with spontaneous pneumothorax except for one patient with COPD. None of the patients’ imaging prior to diagnosis of pneumothorax revealed any underlying blebs. Median time from symptom onset to diagnosis of pneumothorax was 17 days. One of the patients had tension pneumothorax, two had bilateral pneumothorax and three had pneumomediastinum (Figure 1). Four patients required chest tube placement, three required escalation to ICU, of which two died.Table 1. Demographics and Clinical Characteristics of Patients with Spontaneous Pneumothorax Figure 1. CT imaging before (left) and after (right) Spontaneous Pneumothorax ConclusionSpontaneous pneumothorax may be an unrecognized late complication of COVID-19 pneumonia. In hospitalized patients with acute respiratory decompensation, spontaneous pneumothorax should be considered as part of the differential diagnosis. Repeat chest imaging should be considered in these cases.Disclosures All Authors: No reported disclosures

534. Halting a SARS-COV2 Outbreak in a Veterans Affairs Nursing Home

BackgroundHealth care systems have been significantly overwhelmed during the SARS-CoV-2 (SC2) pandemic. Cases in the USA have exceeded 1.9 million with over 40% of deaths occurring in nursing homes and assisting living facilities. We describe our experience in controlling an outbreak in our community living centers (CLC)MethodsWe retrospectively reviewed the charts of Veterans with positive nasopharyngeal (NP) RT-PCR for SC2 from March 24 to April 18, 2020 in 2 neighboring CLC units (80 bed capacity), at Northport Affairs Medical Center.ResultsTwenty five Veterans (24 men) tested positive for SC2. Of these, 5 remained asymptomatic, 9 got hospitalized, 6 died. No coinfection with influenza or other respiratory viruses identified. 11 health care workers (HCW) tested positive. Figure 1 shows test results by date. Table 1 summarizes the demographic characteristics, medical history, and laboratory findings. The median age was 74 years, with no difference in age between recovered and deceased, 73 vs. 77, P:0.105. Simplified acute physiology score (SAPS) II score was higher in the deceased group (P=0.001) and so were D-dimer (admission and peak levels), CRP, LDH, and peak ferritin/procalcitonin levels. There was no ICU admission. Figure 2 illustrates the CLC 1 and 2 outline of beds depicting positive cases in sequence of detection. Initial spread of the virus was fast, affecting residents and HCW. CLC visits were prohibited, floating of staff minimized, internal group activities halted, infection control measures and education on proper use of personal protective equipment provided. A SC2 (or “COVID”) unit was created in CLC1 and all patients and staff got tested. Withdrawal of isolation precautions required resolution of symptoms, and two sequential negative NP PCR tests which were obtained after 14 days from diagnosis. If the PCR was positive, a repeat test was obtained in 72 hours. 13 patients had persistent positive PCR for average 32 days (19 to 52) since diagnosis. 7/13 got tested and all were positive for SC2 IgG antibody.SARS-CoV -2 Outbreak in VA Nursing Home, Dates of Tests Bed Outline of CLCs Depicting the Location And Numerical Sequence of Positive Tests Comparison Between Recovered vs Deceased Nursing Home Veterans with COVID-19 ConclusionControlling SARS-CoV-2 outbreaks in nursing homes is a unique challenge as the virus can spread quickly among residents and staff. Mortality rate in our cohort was 24%. Prompt, effective isolation and broad testing was instrumental in halting the SC2 (COVID-19) outbreak.Disclosures All Authors: No reported disclosures

403. Study of early and late readmissions with COVID-19: A retrospective analysis

BackgroundMichigan was one of the severely impacted regions during the initial COVID-19 surge. An institutional protocol with early methylprednisolone (MP) to treat COVID-19 patients requiring supplemental oxygen was implemented. We sought to study characteristics of these patients who were readmitted with infectious and non-infectious diagnoses.MethodsA retrospective analysis of 21 COVID-19 readmitted patients initially admitted between 3/10/2020 and 4/20/2020 (early 0–7, late 8–30 days) was done. Total of 455 COVID-19 patients, confirmed by a positive nasopharyngeal RT-PCR were admitted during this time period. Demographic data, clinical characteristics, laboratory and radiographic results and treatments were compared among the early and late readmission groups. Univariate and logistic regression analysis were performed to study the risk factors associated with early readmission and worsening of COVID-19 pneumonia. Secondary analyses were performed comparing worsening COVID-19 pneumonia with other readmission diagnoses.Results4.6% (21/455) were readmitted, 14 early vs 7 late (median age 75 vs 65 yrs). Most early readmissions were COVID-19 related and 8 out of 14 had worsening COVID-19 pneumonia based on clinical picture, laboratory and imaging findings. Readmitted patients with worsening COVID-19 related pneumonia had significantly elevated CRP and lower ALC compared to last discharge value (Table 1). None of the late readmissions required MP. A total of 8 readmissions had bacterial coinfections (1/8 COVID-19 related) (Table 2). Bacterial infections unrelated to COVID-19 were aspiration pneumonia (2), urinary tract infection (2), enterococcal bacteremia from stercoral colitis (1), sacral osteomyelitis (1), and infected BKA stump (1). Each increasing day of MP duration during the first admission reduced the likelihood of early readmission by approximately 10% (OR 0.90, 95% CI 0.63–1.2, p=0.56) (Table 3). 1/14 and 0/7 patients died amongst early and late readmissions respectively.Table 1: Characteristics of early and late readmissions in COVID-19 patients Table 2: Readmission Diagnosis Table 3: Univariate and Multivariate Analysis of Readmissions ConclusionEarly MP in COVID-19 pneumonia was not associated with increased risk of early secondary bacterial infections in the readmitted patients. Optimal duration of MP in patients with COVID-19 pneumonia needs to be defined.Disclosures All Authors: No reported disclosures