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1.
Br J Ophthalmol ; 106(9): 1313-1317, 2022 09.
Article in English | MEDLINE | ID: covidwho-2253912

ABSTRACT

PURPOSE: Presence of SARS-CoV-2 RNA in human retinal biopsies (RBs) was previously reported by us. In this consecutive study, we analysed RB and optic nerve biopsies (ONBs) in deceased patients with confirmed COVID-19 assessing viral RNA load, possible virus replication and infectivity. PATIENTS AND METHODS: In this case series, 14 eyes of 14 deceased patients with COVID-19 were enucleated during autopsy. RB and ONB were subjected to molecular detection of viral RNA, virus cultivation and immunohistochemistry. SARS-CoV-2 RNA loads were compared with RNA loads in the respective throat swabs, vitreous humour and blood samples. RESULTS: SARS-CoV-2 RNA was detected in 7/14 RBs and in 10/13 ONBs. While virus isolation failed and immunohistochemistry of SARS-CoV-2 spike protein was negative, subgenomic RNA (sgRNA) was detectable (40% RB; 60% ONB). CONCLUSION: SARS-CoV-2 RNA is detectable in RB and ONB of patients with COVID-19. Presence of sgRNA could point to a SARS-CoV-2 infection of neuronal tissue, but as virus isolation failed and immunohistochemistry of SARS-CoV-2 spike protein was negative, an active infection seems unlikely.


Subject(s)
COVID-19 , SARS-CoV-2 , Genomics , Humans , Optic Nerve , RNA, Viral/analysis , RNA, Viral/genetics , Retina , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus
2.
Microbiol Spectr ; 11(1): e0410322, 2023 02 14.
Article in English | MEDLINE | ID: covidwho-2246385

ABSTRACT

In vitro data suggest the monoclonal antibody sotrovimab may have lost inhibitory capability against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant. We aimed to provide real-life data on clinical outcomes in hospitalized patients. We retrospectively analyzed patients who were treated at the University Medical Center Hamburg-Eppendorf, Germany, between December 2021 and June 2022. Out of all 1,254 patients, 185 were treated with sotrovimab: 147 patients received sotrovimab monotherapy, and 38 received combination treatment with sotrovimab and remdesivir. We compared in-hospital mortality for the different treatment regimens for patients treated on regular wards and the intensive care unit separately and performed propensity score matching by age, sex, comorbidities, immunosuppression, and additional dexamethasone treatment to select patients who did not receive antiviral treatment for comparison. No difference in in-hospital mortality was observed between any of the treatment groups and the respective control groups. These findings underline that sotrovimab adds no clinical benefit for hospitalized patients with SARS-CoV-2 Omicron variant infections. IMPORTANCE This study shows that among hospitalized patients with SARS-CoV-2 Omicron variant infection at risk of disease progression, treatment with sotrovimab alone or in combination with remdesivir did not decrease in-hospital mortality. These real-world clinical findings in combination with previous in vitro data about lacking neutralizing activity of sotrovimab against SARS-CoV-2 Omicron variant do not support sotrovimab as a treatment option in these patients.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Retrospective Studies , Propensity Score , Antibodies, Neutralizing
3.
Emerg Infect Dis ; 29(3): 652-656, 2023 03.
Article in English | MEDLINE | ID: covidwho-2241406

ABSTRACT

We performed autopsies on persons in Germany who died from COVID-19 and observed higher nasopharyngeal SARS-CoV-2 viral loads for variants of concern (VOC) compared with non-VOC lineages. Pulmonary inflammation and damage appeared higher in non-VOC than VOC lineages until adjusted for vaccination status, suggesting COVID-19 vaccination may mitigate pulmonary damage.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Autopsy , COVID-19 Vaccines , Germany
4.
J Clin Immunol ; 2022 Sep 19.
Article in English | MEDLINE | ID: covidwho-2240406

ABSTRACT

Almost 2 years into the pandemic and with vaccination of children significantly lagging behind adults, long-term pediatric humoral immune responses to SARS-CoV-2 are understudied. The C19.CHILD Hamburg (COVID-19 Child Health Investigation of Latent Disease) Study is a prospective cohort study designed to identify and follow up children and their household contacts infected in the early 2020 first wave of SARS-CoV-2. We screened 6113 children < 18 years by nasopharyngeal swab-PCR in a low-incidence setting after general lockdown, from May 11 to June 30, 2020. A total of 4657 participants underwent antibody testing. Positive tests were followed up by repeated PCR and serological testing of all household contacts over 6 months. In total, the study identified 67 seropositive children (1.44%); the median time after infection at first presentation was 83 days post-symptom onset (PSO). Follow-up of household contacts showed less than 100% seroprevalence in most families, with higher seroprevalence in families with adult index cases compared to pediatric index cases (OR 1.79, P = 0.047). Most importantly, children showed sustained seroconversion up to 9 months PSO, and serum antibody concentrations persistently surpassed adult levels (ratio serum IgG spike children vs. adults 90 days PSO 1.75, P < 0.001; 180 days 1.38, P = 0.01; 270 days 1.54, P = 0.001). In a low-incidence setting, SARS-CoV-2 infection and humoral immune response present distinct patterns in children including higher antibody levels, and lower seroprevalence in families with pediatric index cases. Children show long-term SARS-CoV-2 antibody responses. These findings are relevant to novel variants with increased disease burden in children, as well as for the planning of age-appropriate vaccination strategies.

6.
Int J Environ Res Public Health ; 19(24)2022 12 19.
Article in English | MEDLINE | ID: covidwho-2166578

ABSTRACT

SARS-CoV-2 RNA is frequently identified in patient rooms and it was speculated that the viral load quantified by PCR might correlate with infectivity of surfaces. To evaluate Ct values for the prediction of infectivity, we investigated contaminated surfaces and Ct-value changes after disinfection. Viral RNA was detected on 37 of 143 investigated surfaces of an ICU. However, virus isolation failed for surfaces with a high viral RNA load. Also, SARS-CoV-2 could not be cultivated from surfaces artificially contaminated with patient specimens. In order to evaluate the significance of Ct values more precisely, we used surrogate enveloped bacteriophage Φ6. A strong reduction in Φ6 was achieved by three different disinfection methods. Despite a strong reduction in viability almost no change in the Ct values was observed for UV-C and alcoholic surface disinfectant. Disinfection using ozone resulted in a lack of Φ6 recovery as well as a detectable shift in Ct values indicating strong degradation of the viral RNA. The observed lack of significant effects on the detectable viral RNA after effective disinfection suggest that quantitative PCR is not suitable for predicting the infectivity of SARS-CoV-2 on inanimate surfaces. Ct values should therefore not be considered as markers for infectivity in this context.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , RNA, Viral/genetics , Trust , Patients' Rooms , Disinfection
7.
Emerg Infect Dis ; 28(9): 1765-1769, 2022 09.
Article in English | MEDLINE | ID: covidwho-1974607

ABSTRACT

Beginning in May 2022, a rising number of monkeypox cases were reported in non-monkeypox-endemic countries in the Northern Hemisphere. We adapted 2 published quantitative PCRs for use as a dual-target monkeypox virus test on widely used automated high-throughput PCR systems. We determined analytic performance by serial dilutions of monkeypox virus reference material, which we quantified by digital PCR. We found the lower limit of detection for the combined assays was 4.795 (95% CI 3.6-8.6) copies/mL. We compared clinical performance against a commercial manual orthopoxvirus research use only PCR kit by using clinical remnant swab samples. Our assay showed 100% positive (n = 11) and 100% negative (n = 56) agreement. Timely and scalable PCR tests are crucial for limiting further spread of monkeypox. The assay we provide streamlines high-throughput molecular testing for monkeypox virus on existing broadly established platforms used for SARS-CoV-2 diagnostic testing.


Subject(s)
COVID-19 , Monkeypox , Humans , Molecular Diagnostic Techniques , Monkeypox/diagnosis , Monkeypox/epidemiology , Monkeypox virus/genetics , SARS-CoV-2/genetics , Sensitivity and Specificity
8.
J Reprod Immunol ; 153: 103685, 2022 09.
Article in English | MEDLINE | ID: covidwho-1966885

ABSTRACT

Breast milk is a pivotal source to provide passive immunity in newborns over the first few months of life. Very little is known about the antibody transfer levels over the period of breastfeeding. We conducted a prospective study in which we evaluated concentrations of anti-SARS-CoV-2 Spike IgA and RBD IgG/M/A antibodies in maternal serum and breast milk over a duration of up to 6 months after delivery. We compared antibody levels in women with confirmed COVID-19 infection during pregnancy (n = 16) to women with prenatal SARS-CoV-2 vaccination (n = 5). Among the recovered women, n = 7 (44%) had been vaccinated during the lactation period as well. We observed intraindividual moderate positive correlations between antibody levels in maternal serum and breast milk (r = 0.73, p-value<0.0001), whereupon the median levels were generally higher in serum. Anti-RBD IgA/M/G transfer into breast milk was significantly higher in women recovered from COVID-19 and vaccinated during lactation (35.15 AU/ml; IQR 21.96-66.89 AU/ml) compared to the nonvaccinated recovered group (1.26 AU/ml; IQR 0.49-3.81 AU/ml), as well as in the vaccinated only group (4.52 AU/ml; IQR 3.19-6.23 AU/ml). Notably, the antibody level in breast milk post SARS-CoV-2 infection sharply increased following a single dose of vaccine. Breast milk antibodies in all groups showed neutralization capacities against an early pandemic SARS-CoV-2 isolate (HH-1) and moreover, also against the Omicron variant, although with lower antibody titer. Our findings highlight the importance of booster vaccinations especially after SARS-CoV-2 infection in pregnancy in order to optimize protection in mother and newborn.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Viral , Breast Feeding , COVID-19/prevention & control , COVID-19 Vaccines , Cohort Studies , Female , Humans , Immunoglobulin A , Immunoglobulin G , Infant, Newborn , Lactation , Milk, Human , Prospective Studies , SARS-CoV-2 , Vaccination
9.
J Med Virol ; 94(10): 5038-5043, 2022 10.
Article in English | MEDLINE | ID: covidwho-1888757

ABSTRACT

We aimed to provide in vitro data on the neutralization capacity of different monoclonal antibody (mAb) preparations against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delta and omicron variant, respectively, and describe the in vivo RNA kinetics of coronavirus disease 2019 (COVID-19) patients treated with the respective mAbs. Virus neutralization assays were performed to assess the neutralizing effect of the mAb formulations casirivimab/imdevimab and sotrovimab on the SARS-CoV-2 delta and omicron variant. Additionally, respiratory tract SARS-CoV-2 RNA kinetics are provided for 25 COVID-19 patients infected with either delta variant (n = 18) or omicron variant (n = 7) treated with the respective mAb formulations during their hospital stay. In the virus neutralization assay, sotrovimab exhibits neutralizing capacity at therapeutically achievable concentrations against the SARS-CoV-2 delta and omicron variant. In contrast, casivirimab/imdevimab had neutralizing capacity against the delta variant but failed neutralization against the omicron variant except for a very high concentration above the currently recommended therapeutic dosage. In patients with delta variant infections treated with casivirimab/imdevimab, we observed a rapid decrease of respiratory viral RNA at day 3 after mAb therapy. In contrast, no such prompt decline was observed in patients with delta variant or omicron variant infections receiving sotrovimab.


Subject(s)
Antineoplastic Agents, Immunological , COVID-19 Drug Treatment , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized , Antibodies, Neutralizing , Antibodies, Viral , Humans , Membrane Glycoproteins/genetics , Neutralization Tests , RNA, Viral , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Treatment Outcome , Viral Envelope Proteins/genetics
10.
J Clin Med ; 11(12)2022 Jun 09.
Article in English | MEDLINE | ID: covidwho-1884245

ABSTRACT

In the tissue donation field, to prevent pathogen transmission, all donors are screened by postmortem swabs for SARS-CoV-2 using qRT-PCR. Corneas from donors who tested positive for SARS-CoV-2 were subjected to further investigations. Corneal transplants and culture medium from positive donors were cultured under appropriate safety conditions for further analyses. Cornea tissue samples, including sclera/limbus/cornea, and culture media were taken at different time points for testing for SARS-CoV-2 using qRT-PCR, immunohistochemistry (IHC) and subgenomic RNA (sgRNA) analysis. Between January and May 2021, in four donors with initial negative premortem rapid tests, SARS-CoV-2 was detected post-mortem using qRT-PCR. In these cases, SARS-CoV-2 was observed at the beginning of cultivation in both tissue and culture medium using qRT-PCR and IHC. The virus was mainly localized in the limbus epithelial cells, with a stable detection level. Premortem rapid tests are potentially insufficient to exclude SARS-CoV-2 infection in corneal donors. While, for SARS-CoV-2, the risk of infection via transplants is considered low, a residual risk remains for presymptomatic new infections. However, our investigations provide the first indications that, with organ cultures, the risk of virus transmission is minimized due to the longer minimum culture period.

11.
Viruses ; 14(3)2022 03 15.
Article in English | MEDLINE | ID: covidwho-1742730

ABSTRACT

BACKGROUND: The recently emerged SARS-CoV-2 B.1.1.529 lineage and its sublineages (Omicron variant) pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized populations and its resistance to currently available monoclonal antibody therapies. RT-PCR-based variant tests can be used to screen large sample-sets rapidly and accurately for relevant variants of concern (VOC). The aim of this study was to establish and validate a multiplex assay on the cobas 6800/8800 systems to allow discrimination between the two currently circulating VOCs, Omicron and Delta, in clinical samples. METHODS: Primers and probes were evaluated for multiplex compatibility. Analytic performance was assessed using cell culture supernatant of an Omicron variant isolate and a clinical Delta variant sample, normalized to WHO-Standard. Clinical performance of the multiplex assay was benchmarked against NGS results. RESULTS: In silico testing of all oligos showed no interactions with a high risk of primer-dimer formation or amplification of human DNA/RNA. Over 99.9% of all currently available Omicron variant sequences are a perfect match for at least one of the three Omicron targets included in the multiplex. Analytic sensitivity was determined as 19.0 IU/mL (CI95%: 12.9-132.2 IU/mL) for the A67V + del-HV69-70 target, 193.9 IU/mL (CI95%: 144.7-334.7 IU/mL) for the E484A target, 35.5 IU/mL (CI95%: 23.3-158.0 IU/mL) for the N679K + P681H target and 105.0 IU/mL (CI95%: 80.7-129.3 IU/mL) for the P681R target. All sequence variances were correctly detected in the clinical sample set (225/225 Targets). CONCLUSION: RT-PCR-based variant screening compared to whole genome sequencing is both rapid and reliable in detecting relevant sequence variations in SARS-CoV-2 positive samples to exclude or verify relevant VOCs. This allows short-term decision-making, e.g., for patient treatment or public health measures.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , DNA Primers/genetics , High-Throughput Screening Assays , Humans , SARS-CoV-2/genetics
12.
Int J Hyg Environ Health ; 240: 113928, 2022 03.
Article in English | MEDLINE | ID: covidwho-1648655

ABSTRACT

We describe two outbreaks of SARS-CoV-2 in daycare centers in the metropolitan area of Hamburg, Germany. The outbreaks occurred in rapid chronological succession, in neighborhoods with a very similar sociodemographic structure, thus allowing for cross-comparison of these events. We combined classical and molecular epidemiologic investigation methods to study infection entry, spread within the facilities, and subsequent transmission of infections to households. Epidemiologic and molecular evidence suggests a superspreading event with a non-variant of concern (non-VOC) SARS CoV-2 strain at the root of the first outbreak. The second outbreak involved two childcare facilities experiencing infection activity with the variant of concern (VOC) B.1.1.7 (Alpha). We show that the index cases in all outbreaks had been childcare workers, and that children contributed substantially to secondary transmission of SARS-CoV-2 infection from childcare facilities to households. The frequency of secondary transmissions in households originating from B.1.1.7-infected children was increased compared to children with non-VOC infections. Self-reported symptoms, particularly cough and rhinitis, occurred more frequently in B.1.1.7-infected children. Especially in light of the rapidly spreading VOC B.1.617.2 (Delta), our data underline the notion that rigorous SARS-CoV-2 testing in combination with screening of contacts regardless of symptoms is an important measure to prevent SARS-CoV-2 infection of unvaccinated individuals in daycare centers and associated households.


Subject(s)
COVID-19 , Child Day Care Centers , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/virology , COVID-19 Testing , Child , Disease Outbreaks , Germany/epidemiology , Humans
13.
PLoS One ; 16(12): e0258450, 2021.
Article in English | MEDLINE | ID: covidwho-1581814

ABSTRACT

BACKGROUND AND AIMS: Patients with liver cirrhosis (LC) are considered to be at increased risk for mortality when acquiring SARS-CoV-2 infection and subsequently developing Corona Virus Disease 2019 (COVID-19). During the COVID-19 pandemic, hospitals are regarded as sites with increased risk of infection. Therefore, patient contacts are often limited to urgent indications, which could negatively affect disease monitoring. However, data regarding actual infection rates in cirrhotic patients is limited. The aim of this prospective study was to assess the incidence of COVID-19 in patients with LC with/without hepatocellular carcinoma (HCC) with physical presentation at our University Medical Center. METHODS: Patients were enrolled between 1st April and 30th June 2020 at the University Medical Center Hamburg-Eppendorf, Germany. Symptoms of upper airway infection at baseline and presence of SARS-CoV-2 antibodies (IgG/IgM/IgA) were assessed at baseline and follow-up (FU) using an Electro-chemiluminescence immunoassay (Roche Elecsys). FU visits, including liver function test, clinical assessment and symptom questionnaire, were conducted after 6-8 weeks (FU-1) and 6 months (FU-2). Prior to inclusion of the first patient, obligatory face masks and personal distance were implemented as protective measures. RESULTS: A total of 150 patients were enrolled, 23% (n = 35) also had diagnosis of HCC (median age: 64 years, range: 19-86), 69% were male. Liver function according to Child-Pugh score (CPS) was: CPS A: 46% (n = 62); CPS B: 37% (n = 50); CPS C: 17% (n = 23). Clinical symptoms indicating upper airway infection were present in 53% (n = 77): shortness of breath (n = 40) and coughing (n = 28) were the most frequent. For the 150 patients enrolled, 284 outpatient visits were registered and 33 patients were admitted to the University Medical Center during the follow-up period. After a median of 52 days, n = 110 patients completed FU-1 and n = 72 completed FU-2 after a median of 6.1 months. Only in one patient, an 80-year-old man with stable liver function (CPS A) and advanced HCC, SARS-CoV-2 antibodies were detected at baseline and FU-1, while antibody testing was negative in the remaining patients at baseline, FU-1 and FU-2. CONCLUSION: The incidence of COVID-19 at our tertiary medical center during the pandemic was low in LC and HCC patients, when simple protective measures were implemented. Therefore, a routine care for patients with chronic liver diseases does not increase the risk of SARS-CoV-2 infection and should be maintained with protective measures.


Subject(s)
COVID-19/epidemiology , Carcinoma, Hepatocellular/virology , Liver Cirrhosis/virology , Adult , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/complications , Cohort Studies , Female , Germany/epidemiology , Humans , Incidence , Liver Cirrhosis/complications , Liver Neoplasms/complications , Liver Neoplasms/virology , Male , Middle Aged , Pandemics , Prospective Studies , SARS-CoV-2/pathogenicity , Tertiary Care Centers/trends
14.
J Med Virol ; 94(5): 1920-1925, 2022 05.
Article in English | MEDLINE | ID: covidwho-1589024

ABSTRACT

The role of respiratory superinfections in patients with coronavirus disease 2019 (COVID-19) pneumonia remains unclear. We investigated the prevalence of early- and late-onset superinfections in invasively ventilated patients with COVID-19 pneumonia admitted to our department of intensive care medicine between March 2020 and November 2020. Of the 102 cases, 74 (72.5%) received invasive ventilation and were tested for viral, bacterial, and fungal pathogens on Days 0-7, 8-14, and 15-21 after the initiation of mechanical ventilation. Approximately 45% developed one or more respiratory superinfections. There was a clear correlation between the duration of invasive ventilation and the prevalence of coinfecting pathogens. Male patients with obesity and those suffering from chronic obstructive pulmonary disease and/or diabetes mellitus had a significantly higher probability to develop a respiratory superinfection. The prevalence of viral coinfections was high, with a predominance of the herpes simplex virus (HSV), followed by cytomegalovirus. No respiratory viruses or intracellular bacteria were detected in our cohort. We observed a high coincidence between Aspergillus fumigatus and HSV infection. Gram-negative bacteria were the most frequent pathogen group. Klebsiella aerogenes was detected early after intubation, while Klebsiella pneumoniae and Pseudomonas aeruginosa were related to a prolonged respiratory weaning.


Subject(s)
COVID-19 , Superinfection , COVID-19/epidemiology , COVID-19/therapy , Humans , Male , Prevalence , Respiration, Artificial/adverse effects , SARS-CoV-2 , Superinfection/epidemiology , Superinfection/microbiology
15.
Open Forum Infect Dis ; 8(11): ofab509, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1526187

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA loads in patient specimens may act as a clinical outcome predictor in critically ill patients with coronavirus disease 2019 (COVID-19). METHODS: We evaluated the predictive value of viral RNA loads and courses in the blood compared with the upper and lower respiratory tract loads of critically ill COVID-19 patients. Daily specimen collection and viral RNA quantification by reverse transcription quantitative polymerase chain reaction were performed in all consecutive 170 COVID-19 patients between March 2020 and February 2021 during the entire intensive care unit (ICU) stay (4145 samples analyzed). Patients were grouped according to their 90-day outcome as survivors (n=100) or nonsurvivors (n=70). RESULTS: In nonsurvivors, blood SARS-CoV-2 RNA loads were significantly higher at the time of admission to the ICU (P=.0009). Failure of blood RNA clearance was observed in 33/50 (66%) of the nonsurvivors compared with 12/64 (19%) survivors (P<.0001). As determined by multivariate analysis, taking sociodemographic and clinical parameters into account, blood SARS-CoV-2 RNA load represents a valid and independent predictor of outcome in critically ill COVID-19 patients (odds ratio [OR; log10], 0.23; 95% CI, 0.12-0.42; P<.0001), with a significantly higher effect for survival compared with respiratory tract SARS-CoV-2 RNA loads (OR [log10], 0.75; 95% CI, 0.66-0.85; P<.0001). Blood RNA loads exceeding 2.51×103 SARS-CoV-2 RNA copies/mL were found to indicate a 50% probability of death. Consistently, 29/33 (88%) nonsurvivors with failure of virus clearance exceeded this cutoff value constantly. CONCLUSIONS: Blood SARS-CoV-2 load is an important independent outcome predictor and should be further evaluated for treatment allocation and patient monitoring.

16.
Emerg Infect Dis ; 28(1): 244-247, 2022 01.
Article in English | MEDLINE | ID: covidwho-1496968

ABSTRACT

We investigated the infectivity of 128 severe acute respiratory disease coronavirus 2-associated deaths and evaluated predictive values of standard diagnostic procedures. Maintained infectivity (20%) did not correlate with viral RNA loads but correlated well with anti-S antibody levels. Sensitivity >90% for antigen-detecting rapid diagnostic tests supports their usefulness for assessment.


Subject(s)
COVID-19 , SARS-CoV-2 , Autopsy , Diagnostic Tests, Routine , Humans , Sensitivity and Specificity , Viral Load
17.
Diagnostics (Basel) ; 11(10)2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1444133

ABSTRACT

BACKGROUND: The recent emergence of distinct and highly successful SARS-CoV-2 lineages has substantial implications for individual patients and public health measures. While next-generation-sequencing is routinely performed for surveillance purposes, RT-qPCR can be used to rapidly rule-in or rule-out relevant variants, e.g., in outbreak scenarios. The objective of this study was to create an adaptable and comprehensive toolset for multiplexed Spike-gene SNP detection, which was applied to screen for SARS-CoV-2 B.1.617 lineage variants. METHODS: We created a broad set of single nucleotide polymorphism (SNP)-assays including del-Y144/145, E484K, E484Q, P681H, P681R, L452R, and V1176F based on a highly specific multi-LNA (locked nucleic acid)-probe design to maximize mismatch discrimination. As proof-of-concept, a multiplex-test was compiled and validated (SCOV2-617VOC-UCT) including SNP-detection for L452R, P681R, E484K, and E484Q to provide rapid screening capabilities for the novel B.1.617 lineages. RESULTS: For the multiplex-test (SCOV2-617VOC-UCT), the analytic lower limit of detection was determined as 182 IU/mL for L452R, 144 IU/mL for P681R, and 79 IU/mL for E484Q. A total of 233 clinical samples were tested with the assay, including various on-target and off-target sequences. All SNPs (179/179 positive) were correctly identified as determined by SARS-CoV-2 whole genome sequencing. CONCLUSION: The recurrence of SNP locations and flexibility of methodology presented in this study allows for rapid adaptation to current and future variants. Furthermore, the ability to multiplex various SNP-assays into screening panels improves speed and efficiency for variant testing. We show 100% concordance with whole genome sequencing for a B.1.617.2 screening assay on the cobas6800 high-throughput system.

18.
J Infect ; 83(5): 589-593, 2021 11.
Article in English | MEDLINE | ID: covidwho-1401632

ABSTRACT

INTRODUCTION: The large number of asymptomatic SARS-CoV-2 infections necessitates general screening of employees. We evaluate the performance of a SARS-CoV-2 screening program in asymptomatic healthcare-workers (HCW), utilizing self-sampled gargling-solution and sample pooling for RT-qPCR. METHODS: We conducted a cross-sectional retrospective study to collect real-life data on the performance of a screening-workflow based on automated-pooling and high-throughput qPCR testing over a 3-month-period at the University Hospital Hamburg. RESULTS: Matrix validation reveals that lower limit of detection for SARS-CoV-2 RNA in gargling-solution was 180 copies/mL (5-sample-pool). A total of 55,122 self-collected gargle samples (= 7513 HCWs) was analyzed. The median time to result was 8.5 hours (IQR 7.2-10.8). Of 11,192 pools analyzed, 11,041 (98.7%) were negative, 69 (0.6%) were positive and 82 (0.7%) were invalid. Individual testing of pool participants revealed 57 SARS-CoV-2 previously unrecognized infections. All 57 HCWs were either pre-symptomatic or asymptomatic (prevalence 0.76%,CI95%0.58-0.98%). Accuracy based on HCWs with gargle-solution and NP-swab available within 3-day-interval (N = 521) was 99.5% (CI95%98.3-99.9%), sensitivity 88.9% (CI95%65.3-98.6%) while specificity 99.8% (CI95%98.9-99.9). CONCLUSION: This workflow was highly effective in identifying SARS-CoV-2 positive HCWs, thereby lowering the potential of inter-HCW and HCW-patient transmissions. Automated-sample-pooling helped to conserve qPCR reagents and represents a promising alternative strategy to antigen testing in mass-screening programs.


Subject(s)
COVID-19 , SARS-CoV-2 , Cross-Sectional Studies , Delivery of Health Care , Humans , RNA, Viral , Retrospective Studies , Workflow
20.
Infect Dis Ther ; 10(4): 2371-2379, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1347448

ABSTRACT

INTRODUCTION: Molecular testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to suffer from delays and shortages. Antigen tests have recently emerged as a viable alternative to detect patients with high viral loads, associated with elevated risk of transmission. While rapid lateral flow tests greatly improved accessibility of SARS-CoV-2 detection in critical areas, their manual nature limits scalability and suitability for large-scale testing schemes. The Elecsys® SARS-CoV-2 Antigen assay allows antigen immunoassays to be carried out on fully automated high-throughput serology platforms. METHODS: A total of 3139 nasopharyngeal and oropharyngeal swabs were collected at 3 different testing sites in Germany. Swab samples were pre-characterized by reverse transcription real-time polymerase chain reaction (RT-qPCR) and consecutively subjected to the antigen immunoassay on either the cobas e 411 or cobas e 801 analyzer. RESULTS: Of the tested respiratory samples, 392 were PCR positive for SARS-CoV-2 RNA. Median concentration was 2.95 × 104 (interquartile range [IQR] 5.1 × 102-3.5 × 106) copies/ml. Overall sensitivity and specificity of the antigen immunoassay were 60.2% (95% confidence interval [CI] 55.2-65.1) and 99.9% (95% CI 99.6-100.0), respectively. A 93.7% (95% CI 89.7-96.5) sensitivity was achieved at a viral RNA concentration ≥ 104 copies/ml (~ cycle threshold [Ct] value < 29.9). CONCLUSION: The Elecsys SARS-CoV-2 Antigen assay reliably detected patient samples with viral loads ≥ 10,000 copies/ml. It thus represents a viable high-throughput alternative for screening of patients or in situations where PCR testing is not readily available.

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