Analytical and clinical evaluation of four commercial SARS-CoV-2 serological immunoassays in hospitalized patients and ambulatory individuals

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Hospitalized patients seroconverted at ≥ 3 weeks pso.

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Ambulatory symptomatic individuals seroconverted at 14 days pso.

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Illness’ severity degree and infection phase impacted the longitudinal Ab changes.

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Five “severe-to-critically” ill patients have positive Ab levels up to 16 weeks pso.

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Total Ab immunoassay, compared to IgG, present a better sensitivity and specificity.

Background

This study aimed to compare four anti-SARS-CoV-2 immunoassays in populations presenting different clinical severity levels.

Methods

Three populations were included: “severe-to-critical” ICU-hospitalized patients (n = 18), “mild-to-moderate” hospitalized patients (n = 16) and non-hospitalized symptomatic patients (n = 24). Four commercial immunoassays were analyzed and validated: anti-IgG ARCHITECT® (Abbott), anti-Total antibodies (Ab) VITROS® (Ortho Clinical Diagnostics), anti-IgG NovaLisa® (NovaTec Immundiagnostica) and Healgen® IgM and IgG (Zhejiang Orient Gene Biotech). Sensitivities were evaluated according to days post-symptoms onset (pso). Specificities were evaluated on SARS-CoV-2-negative control sera collected before January 2020.

Results

A majority of severe-to-critically ill patients showed detectable Ab already at day 14 and sensitivities reached 100 % after 22 days pso. For patients with “mild-to-moderate” illness, sensitivities increased by at least 5-fold from day 0 to day 14 pso. Non-hospitalized symptomatic individuals already seroconverted at day 14 days pso with 100 % sensitivities for Total Ab VITROS®. Specificities were evaluated at 97 % for ARCHITECT® and NovaLisa®, 98 % for VITROS® and at 94 % for Healgen® combined IgM and IgG. Five “severe-to-critically” ill patients presented high positive Ab levels for at least 16 weeks pso.

Conclusion

The Ab levels and the evaluated sensitivities, representing the true positive rate, increased overtime and were related to the COVID-19 severity. Automated Total Ab immunoassay showed better sensitivities and specificity for immunological surveillance and vaccine evaluation.

Controlling an optical vortex array from a vortex phase plate, mode converter, and spatial light modulator

In this Letter, we propose a convenient method of generating an optical vortex (OV) array, in which the size and quantity can be controlled by employing vortex phase plates, a mode converter, and a spatial light modulator into a simple optical system. Different sizes of OV arrays are generated from the superposition of crossed Hermite-Gaussian (HG) modes possessing equal or unequal orders and mutually orthogonal circular polarizations. We experimentally and theoretically demonstrate a series of vector superposed optical fields. Here the sizes of the OV arrays, as well as the quantities of OVs, are defined in terms of specific sets of HG bases. Our results indicate that a simple setup can be used to effectively generate and control OVs and OV arrays.

Nosocomial outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae among cardiothoracic surgical patients: causes and consequences

BACKGROUND

Enterobacteriaceae are recognized as leading pathogens of healthcare-associated infections.

AIM

To report the investigation of a nosocomial outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae affecting cardiothoracic surgery patients in a Belgian academic hospital.

METHODS

Cases were defined based on epidemiological and microbiological investigations, including molecular typing using repetitive element-based polymerase chain reaction and multi-locus sequence typing. Case-control studies followed by field evaluations allowed the identification of a possible reservoir, and the retrospective assessment of human and financial consequences.

FINDINGS

Over a three-month period, 42 patients were infected or colonized by CTX-M-15-producing E. cloacae strains that belonged to the same clonal lineage. Acquisition mainly occurred in the intensive care unit (N = 23) and in the cardiothoracic surgery ward (N = 16). All but one patient had, prior to acquisition, undergone a cardiothoracic surgical procedure, monitored by the same transoesophageal echocardiography (TOE) probe in the operating room. Despite negative microbiological culture results, the exclusion of the suspected probe resulted in rapid termination of the outbreak. Overall, the outbreak was associated with a high mortality rate among infected patients (40%) as well as significant costs (€266,550).

CONCLUSION

The outbreak was indirectly shown to be associated with the contamination of a manually disinfected TOE probe used per-operatively during cardiothoracic surgery procedures, because withdrawal of the putative device led to rapid termination of the outbreak.

Kaleidoscope vortex lasers generated from astigmatic cavities with longitudinal-transverse coupling

We propose an efficient and robust method to generate the kaleidoscope vortex beam by employing an astigmatic laser cavity with an extra-cavity cylindrical lens. The kaleidoscope vortex beam is arising from the superposition of Laguerre-Gaussian modes with the longitudinal-transverse coupling effect in the laser cavity. The superposed Laguerre-Gaussian mode leads to the formation of complex phase singularities and implies the participation of different optical orbital angular momentum involved in a single kaleidoscope vortex beam. We experimentally demonstrate that a series of kaleidoscope vortex beams with different symmetry are systematically achieved by using a simple setup. The output power of the laser is dependent on the cavity length. This approach is expected to create high-order optical vortex beams and pave the way for optical entanglement.

Generation of flower high-order Poincaré sphere laser beams from a spatial light modulator

We propose and experimentally demonstrate a new complex laser beam with inhomogeneous polarization distributions mapping onto high-order Poincaré spheres (HOPSs). The complex laser mode is achieved by superposition of Laguerre-Gaussian modes and manifests exotic flower-like localization on intensity and phase profiles. A simple optical system is used to generate a polarization-variant distribution on the complex laser mode by superposition of orthogonal circular polarizations with opposite topological charges. Numerical analyses of the polarization distribution are consistent with the experimental results. The novel flower HOPS beams can act as a new light source for photonic applications.

Central skull base osteomyelitis: a rare but life-threatening disease

We present the case of a 70-year-old non-diabetic patient who presented to the emergency department with unrelenting otalgia. A severe otitis externa (OE) and mastoiditis were treated with broad spectrum antibiotics and surgical drainage. No bacteria was isolated from surgical samples. Because the otalgia persisted, a magnetic resonance (MR) was performed and showed an infiltrating process at the skull base. Biopsies failed to prove malignancy or granulomatosis. The patient's neurological state deteriorated. The suspicion of a skull base osteomyelitis (SBO) was raised and proven by CT-guided biopsies that grew Pseudomonas aeruginosa. Meropenem and ciprofloxacin, given for 8 weeks, lead to a fast clinical improvement and a full recovery. SBO is uncommon, often complicating severe OE. Pseudomonas aeruginosa is the main pathogen. Prompt diagnosis and adequate antibiotherapy are required to lower mortality and morbidity. The diagnosis may be delayed because of unawareness and large differential diagnosis including solid neoplasic tumours, malignant hemopathies and granulomatosis.

Clinical, virological and epidemiological assessment of 2009 influenza A (H1N1) pandemic in a Belgian university hospital

BACKGROUND

Recommendations were applied before and during the Belgian pandemic (2009) H1N1 influenza wave at a university hospital (420 beds), for optimizing isolation processes and therapeutic management of possible and confirmed infected cases.

METHODS

All patients presenting to the Emergency Department (ED) between August 1st and December 31st 2009 were screened for ILI symptoms, and were isolated for clinical assessment in case of positive screening. Patients categorized as possible influenza cases and who required hospitalization were isolated in dedicated wards. Specific diagnostic algorithms were implemented. Medical charts were retrospectively reviewed and matched with results of the microbiology laboratory. Patient's characteristics were analyzed, the contribution of laboratory diagnosis on therapy and lengh of stay (LOS) in isolation was also assessed.

RESULTS

310 patients out of 6068 had a positive screening for ILI, of these, 265 were retained as possible influenza cases and 139 required hospitalization. Twenty-eight children (8 requiring hospitalization) and 20 hospitalized adult patients had confirmed influenza infection. Five adult patients were admitted to the intensive care unit (ICU), 3 requiring extracorporeal membrane oxygenation (ECMO). There was no death related to the new influenza strain. The majority of confirmed patients were diagnosed during the Belgian epidemic wave, with a sensitivity of antigen detection of 50% in children and 35% in adults comparatively to real-time PCR (RT-PCR).

CONCLUSIONS

The impact of (2009) H1N1 pandemic influenza remained limited, except for ICU patients requiring ECMO. Implementation of screening, isolation, and virological diagnosis processes led to significant improvement of patient management.

Signature size in the psychiatric diagnosis: a significant clinical sign?

To test the hypothesis that patients' signatures may have a useful potential in making psychiatric diagnoses, the authors conducted a correlation study between signature sizes and psychiatric diagnoses. 252 medical records at St. Louis State Hospital in Missouri, USA, were randomized for the measurement of the signature sizes and assessment of DSM-III diagnoses. Analysis of variance and pair-wise comparison show that the signature size in the manic group is significantly larger than those of any other categories of psychiatric diagnoses (p less than 0.05), and that the signature size of organic mental disorder is significantly larger than those of the normal group (p less than 0.05). The authors suggest that further studies are needed to develop the clinical significance, if any, for interpreting patients' signatures.

Which detoxified alcoholic keeps the first clinic appointment?

One-hundred-eighty consecutive discharged alcoholic inpatients making first outpatient appointments during a 15-month period were studied. Eighty-four (47%) patients who kept their scheduled appointments differed from 96 (53%) patients who failed to keep their appointments, only in numbers of previous hospitalizations. Patients who were admitted four or less times for detoxification previously had a significantly higher rate of keeping the scheduled appointments (x = 5.82, d.f. = 2, P less than 0.05). The variables of sex, age, marital status, length of hospitalization, type of discharge, history of drug use besides marijuana, the use of disulfiram, and state of liver function, did not have significant differences between 'showed' and 'failed' patients. The authors suggest the need for a realistic reappraisal of providing physical and psychiatric care at the outpatient setting for those alcoholics with five or more previous inpatient detoxifications.