COMPARISON OF MOLECULAR AND SEROLOGICAL TESTS FOR SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 (SARS-COV-2) IN POST-EXPOSURE EMPLOYEES OF THE NEPHROLOGY DEPARTMENT.

OBJECTIVE: Introduction: A novel coronavirus SARS-CoV-2 RNA, detected by reverse-transcription polymerase chain reaction (RT-PCR) was identified as the cause of a cluster of pneumonia cases in Wuhan, China. It rapidly spread, at first in China, then resulting in an epidemic in other countries throughout the world. One of such controversial topics is the issue of diagnostics and interpretation of test for COVID-19. According to Polish and global guidelines, the basis for diagnosis is molecular testing - real-time reverse transcriptasepolymerase chain reaction (RT-PCR). Taking all these data into consideration, the aim of the study was to compare RT-PCR with serological test in our employees post-exposure. According to Polish and global guidelines, the basis for diagnosis is molecular testing, real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The aim: To compare RT-PCR with serological test in our employees post-exposure. PATIENTS AND METHODS: Material and methods: 79 employees of the Clinic, 19 men and 60 women in the age range 27-69 years were evaluated. Tests were begun four days after information about the positive test in our "Employee 0" and lasted for 7 days. At first, we made RT-PCR tests on the specimen from nasopharyngeal swab. Then, we accomplished rapid antibodies tests. This test is based on the qualitative assessment of the presence of IgM and IgG antibodies by immunochromatography using a sample of capillary blood from the fingertip. RESULTS: Results: All the tests were negative. No employee developed symptoms during the 7-day follow-up after the end of the tests. CONCLUSION: Conclusions: As routine tests for patients have been implemented widely, but similar solutions for employees have not gained popularity. Use of personal protective equipment (PPE) e.g. facemask and shields, transparent screens, disposable medical uniforms, minimalization the contact time, increasing distance from both colleagues and patients (if possible), and strictly follow sanitary procedures largely contributed to the absence of illness in the surveyed group of employees.

Ventilation and air cleaning to limit aerosol particle concentrations in a gym during the COVID-19 pandemic.

SARS-CoV-2 can spread by close contact through large droplet spray and indirect contact via contaminated objects. There is mounting evidence that it can also be transmitted by inhalation of infected saliva aerosol particles. These particles are generated when breathing, talking, laughing, coughing or sneezing. It can be assumed that aerosol particle concentrations should be kept low in order to minimize the potential risk of airborne virus transmission. This paper presents measurements of aerosol particle concentrations in a gym, where saliva aerosol production is pronounced. 35 test persons performed physical exercise and aerosol particle concentrations, CO2 concentrations, air temperature and relative humidity were obtained in the room of 886 m³. A separate test was used to discriminate between human endogenous and exogenous aerosol particles. Aerosol particle removal by mechanical ventilation and mobile air cleaning units was measured. The gym test showed that ventilation with air-change rate ACH = 2.2 h-1, i.e. 4.5 times the minimum of the Dutch Building Code, was insufficient to stop the significant aerosol concentration rise over 30 min. Air cleaning alone with ACH = 1.39 h-1 had a similar effect as ventilation alone. Simplified mathematical models were engaged to provide further insight into ventilation, air cleaning and deposition. It was shown that combining the above-mentioned ventilation and air cleaning can reduce aerosol particle concentrations with 80 to 90% , depending on aerosol size. This combination of existing ventilation supplemented with air cleaning is energy efficient and can also be applied for other indoor environments.

SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 outbreak in Milan.

BACKGROUND: The Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The aim of this study was to examine the seroprevalence trends of SARS-CoV-2 in healthy asymptomatic adults, and the risk factors and laboratory correlates of positive tests. MATERIALS AND METHODS: We conducted a cross-sectional study in a random sample of blood donors, who were asymptomatic at the time of evaluation, at the beginning of the first phase (February 24th to April 8th 2020; n=789). Presence of IgM/IgG antibodies against the SARS-CoV-2-Nucleocapsid protein was assessed by a lateral flow immunoassay. RESULTS: The test had a 100/98.3 sensitivity/specificity (n=32/120 positive/negative controls, respectively), and the IgG test was validated in a subset by an independent ELISA against the Spike protein (n=34, p<0.001). At the start of the outbreak, the overall adjusted seroprevalence of SARS-CoV-2 was 2.7% (95% CI: 0.3-6%; p<0.0001 vs 120 historical controls). During the study period, characterised by a gradual implementation of social distancing measures, there was a progressive increase in the adjusted seroprevalence to 5.2% (95% CI: 2.4-9.0; 4.5%, 95% CI: 0.9-9.2% according to a Bayesian estimate) due to a rise in IgG reactivity to 5% (95% CI: 2.8-8.2; p=0.004 for trend), but there was no increase in IgM+ (p=not significant). At multivariate logistic regression analysis, IgG reactivity was more frequent in younger individuals (p=0.043), while IgM reactivity was more frequent in individuals aged >45 years (p=0.002). DISCUSSION: SARS-CoV-2 infection was already circulating in Milan at the start of the outbreak. The pattern of IgM/IgG reactivity was influenced by age: IgM was more frequently detected in participants aged >45 years. By the end of April, 2.4-9.0% of healthy adults had evidence of seroconversion.

SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 outbreak in Milan.

BACKGROUND: The Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The aim of this study was to examine the seroprevalence trends of SARS-CoV-2 in healthy asymptomatic adults, and the risk factors and laboratory correlates of positive tests. MATERIALS AND METHODS: We conducted a cross-sectional study in a random sample of blood donors, who were asymptomatic at the time of evaluation, at the beginning of the first phase (February 24th to April 8th 2020; n=789). Presence of IgM/IgG antibodies against the SARS-CoV-2-Nucleocapsid protein was assessed by a lateral flow immunoassay. RESULTS: The test had a 100/98.3 sensitivity/specificity (n=32/120 positive/negative controls, respectively), and the IgG test was validated in a subset by an independent ELISA against the Spike protein (n=34, p<0.001). At the start of the outbreak, the overall adjusted seroprevalence of SARS-CoV-2 was 2.7% (95% CI: 0.3-6%; p<0.0001 vs 120 historical controls). During the study period, characterised by a gradual implementation of social distancing measures, there was a progressive increase in the adjusted seroprevalence to 5.2% (95% CI: 2.4-9.0; 4.5%, 95% CI: 0.9-9.2% according to a Bayesian estimate) due to a rise in IgG reactivity to 5% (95% CI: 2.8-8.2; p=0.004 for trend), but there was no increase in IgM+ (p=not significant). At multivariate logistic regression analysis, IgG reactivity was more frequent in younger individuals (p=0.043), while IgM reactivity was more frequent in individuals aged >45 years (p=0.002). DISCUSSION: SARS-CoV-2 infection was already circulating in Milan at the start of the outbreak. The pattern of IgM/IgG reactivity was influenced by age: IgM was more frequently detected in participants aged >45 years. By the end of April, 2.4-9.0% of healthy adults had evidence of seroconversion.

Development of a Parallel Reaction Monitoring Mass Spectrometry Assay for the Detection of SARS-CoV-2 Spike Glycoprotein and Nucleoprotein.

There is an urgent need for robust and high-throughput methods for SARS-CoV-2 detection in suspected patient samples to facilitate disease management, surveillance, and control. Although nucleic acid detection methods such as reverse transcription polymerase chain reaction (RT-PCR) are the gold standard, during the current pandemic, the deployment of RT-PCR tests has been extremely slow, and key reagents such as PCR primers and RNA extraction kits are at critical shortages. Rapid point-of-care viral antigen detection methods have been previously employed for the diagnosis of respiratory viruses such as influenza and respiratory syncytial viruses. Therefore, the direct detection of SARS-CoV-2 viral antigens in patient samples could also be used for diagnosis of active infection, and alternative methodologies for specific and sensitive viral protein detection should be explored. Targeted mass spectrometry techniques have enabled the identification and quantitation of a defined subset of proteins/peptides at single amino acid resolution with attomole level sensitivity and high reproducibility. Herein, we report a targeted mass spectrometry assay for the detection of SARS-CoV-2 spike protein and nucleoprotein in a relevant biological matrix. Recombinant full-length spike protein and nucleoprotein were digested and proteotypic peptides were selected for parallel reaction monitoring (PRM) quantitation using a high-resolution Orbitrap instrument. A spectral library, which contained seven proteotypic peptides (four from spike protein and three from nucleoprotein) and the top three to four transitions, was generated and evaluated. From the original spectral library, we selected two best performing peptides for the final PRM assay. The assay was evaluated using mock test samples containing inactivated SARS-CoV-2 virions, added to in vitro derived mucus. The PRM assay provided a limit of detection of ∼200 attomoles and a limit of quantitation of ∼ 390 attomoles. Extrapolating from the test samples, the projected titer of virus particles necessary for the detection of SARS-CoV-2 spike and nucleoprotein detection was approximately 2 × 105 viral particles/mL, making it an attractive alternative to RT-PCR assays. Potentially, mass spectrometry-based methods for viral antigen detection may deliver higher throughput and could serve as a complementary diagnostic tool to RT-PCR. Furthermore, this assay could be used to evaluate the presence of SARS-CoV-2 in archived or recently collected biological fluids, in vitro-derived research materials, and wastewater samples.

Extremely high-dose insulin requirement in a diabetic patient with COVID-19: a case report.

BACKGROUND: Detailed description of hyperglycemia management in diabetic patients infected with SARS-CoV-2 remain limited, although patients with diabetes show higher complication and mortality rate than patients without diabetes. Transient non-severe increased insulin requirement in patients hospitalized for medical conditions such as sepsis or myocardial infarction is a well-known phenomenon. However, extremely high-dose insulin requirement remains a very rarely reported entity. Here, we report the case of an extreme and transitory insulin requirement episode in a type 2 diabetic patient presenting an acute respiratory distress syndrome caused by SARS-CoV-2. CASE PRESENTATION: A 57-year-old man resident in Geneva, Switzerland, previously known for type 2 diabetes for 3 years was admitted for an aggravation of his dyspnea. His type 2 diabetes was treated only with metformin and his latest Hb1Ac was 6.1%. Chest CT SCAN showed a bilateral multilobar ground-glass opacification. Twenty-four hours after his admission he presented a worsening of dyspnea and severe hypoxemia requiring a transfer to the intensive care unit rapidly followed by oro-tracheal intubation for mechanical ventilation support. A bronchoalveolar lavage was performed and test of SARS-CoV-2 by RT-qPCR assay was positive. At day 3, he presented a rapidly progressive insulin requirement at a rate of up to 50 units/hour intravenous insulin aspart. Despite the high insulin doses, he maintained an elevated plasma glucose level at 270 mg/dL on average. His extremely high-dose insulin requirement "resolved" at day 9, and the insulin infusion rate was rapidly reduced. CONCLUSIONS: This case may reflect a specific and profound impact of SARS-CoV-2 on metabolic homeostasis, in particular in diabetic patients that appear more prone to complications of COVID-19 infection. Yet, the mechanisms behind this remain to be elucidated. The optimal management of hyperglycemia of diabetic patients infected with SARS-CoV-2 has yet not be defined, however insulin remain the mainstay of treatment approach. Report of extreme dysregulation of chronic conditions such as diabetes in patients with COVID-19 may help clinicians to better take care of patients during the pandemic of SARS-CoV-2. To the best of our knowledge this is the first description of extremely high-dose insulin requirement in patient with COVID-19.

Test sensitivity is secondary to frequency and turnaround time for COVID-19 surveillance.

The COVID-19 pandemic has created a public health crisis. Because SARS-CoV-2 can spread from individuals with pre-symptomatic, symptomatic, and asymptomatic infections, the re-opening of societies and the control of virus spread will be facilitated by robust surveillance, for which virus testing will often be central. After infection, individuals undergo a period of incubation during which viral titers are usually too low to detect, followed by an exponential viral growth, leading to a peak viral load and infectiousness, and ending with declining viral levels and clearance. Given the pattern of viral load kinetics, we model surveillance effectiveness considering test sensitivities, frequency, and sample-to-answer reporting time. These results demonstrate that effective surveillance depends largely on frequency of testing and the speed of reporting, and is only marginally improved by high test sensitivity. We therefore conclude that surveillance should prioritize accessibility, frequency, and sample-to-answer time; analytical limits of detection should be secondary.

Development of a Parallel Reaction Monitoring Mass Spectrometry Assay for the Detection of SARS-CoV-2 Spike Glycoprotein and Nucleoprotein.

There is an urgent need for robust and high-throughput methods for SARS-CoV-2 detection in suspected patient samples to facilitate disease management, surveillance, and control. Although nucleic acid detection methods such as reverse transcription polymerase chain reaction (RT-PCR) are the gold standard, during the current pandemic, the deployment of RT-PCR tests has been extremely slow, and key reagents such as PCR primers and RNA extraction kits are at critical shortages. Rapid point-of-care viral antigen detection methods have been previously employed for the diagnosis of respiratory viruses such as influenza and respiratory syncytial viruses. Therefore, the direct detection of SARS-CoV-2 viral antigens in patient samples could also be used for diagnosis of active infection, and alternative methodologies for specific and sensitive viral protein detection should be explored. Targeted mass spectrometry techniques have enabled the identification and quantitation of a defined subset of proteins/peptides at single amino acid resolution with attomole level sensitivity and high reproducibility. Herein, we report a targeted mass spectrometry assay for the detection of SARS-CoV-2 spike protein and nucleoprotein in a relevant biological matrix. Recombinant full-length spike protein and nucleoprotein were digested and proteotypic peptides were selected for parallel reaction monitoring (PRM) quantitation using a high-resolution Orbitrap instrument. A spectral library, which contained seven proteotypic peptides (four from spike protein and three from nucleoprotein) and the top three to four transitions, was generated and evaluated. From the original spectral library, we selected two best performing peptides for the final PRM assay. The assay was evaluated using mock test samples containing inactivated SARS-CoV-2 virions, added to in vitro derived mucus. The PRM assay provided a limit of detection of ∼200 attomoles and a limit of quantitation of ∼ 390 attomoles. Extrapolating from the test samples, the projected titer of virus particles necessary for the detection of SARS-CoV-2 spike and nucleoprotein detection was approximately 2 × 105 viral particles/mL, making it an attractive alternative to RT-PCR assays. Potentially, mass spectrometry-based methods for viral antigen detection may deliver higher throughput and could serve as a complementary diagnostic tool to RT-PCR. Furthermore, this assay could be used to evaluate the presence of SARS-CoV-2 in archived or recently collected biological fluids, in vitro-derived research materials, and wastewater samples.

Nosocomial outbreak of SARS-CoV-2 infection in a haematological unit - High mortality rate in infected patients with haematologic malignancies.

BACKGROUND: Here we report nosocomial outbreak of COVID-19 among patients in a haematological unit. To our knowledge this is the first report from Central Europe comparing morbidity and mortality in infected and non-infected patients after exposure to SARS-CoV-2. METHODS: The outbreak involved 39 individuals: 19 patients and 20 health care workers. The SARS-CoV-2 test by nasopharyngeal swabs was performed by real-time RT-PCR. Exposed patients were divided into two groups: quarantine patients with and without COVID-19. All patients were prospectively examined at the following time points: 0, 7 days, 14 days, 21 days and 28 days after confirmation or exclusion of SARS-CoV-2. RESULTS: Infection was confirmed in a total of 5/20 health care workers and 10/19 patients. Among the patients positive for SARS-CoV-2 infection, the mortality rate was 36.8 %. The probability of death in patients infected with SARS-CoV-2 increased 8-fold (p = 0.03). Bacterial, fungal, and viral co-infection significantly decreased survival in these patients (p < 0.05). Additionally, the probability of death was much higher in patients older than 40 years of age (p = 0.032). CONCLUSION: This study showed significantly higher mortality rate in COVID-19 patients with haematologic diseases compared to the non-infected patient group. Haematologic patients with COVID-19 have 50 % less chance of survival.

The Loss of Smell and Taste in the COVID-19 Outbreak: a Tale of Many Countries.

PURPOSE OF REVIEW: Olfactory dysfunction in upper airway viral infections (common cold, acute rhinosinusitis) is common (> 60%). During the COVID-19 outbreak, frequency of sensory disorders (smell and/or taste) in affected patients has shown a high variability from 5 to 98%, depending on the methodology, country, and study. RECENT FINDINGS: A sudden, severe, isolated loss of smell and/or taste, in the absence of other upper airway inflammatory diseases (allergic rhinitis, chronic rhinosinusitis, nasal polyposis), should alert individuals and physicians on being potentially affected by COVID-19. The evaluation of smell/taste disorders with a visual analogue scale or an individual olfactory or gustatory test, at the hospital or by telemedicine, to prevent contamination might facilitate an early detection of infected patients and reduce the transmission of SARS-CoV-2. During the COVID-19 outbreak, patients with sudden loss of smell should initiate social distancing and home isolation measures and be tested for SARS-CoV-2 diagnostic test when available. Olfactory training is recommended when smell does not come back after 1 month but can be started earlier.