Microfluidic-based biosensor for SARS-CoV-2 antibodies

This chapter addresses the basis for designing, prototyping, and developing a biosensing platform to support the control of the current global pandemic caused by the COVID-19 disease using an acoustic-based biosensor able to detect and quantify the IgM-and-IgG-specific antibodies against the spike protein (S) receptor-binding domain (RBD) from the SARS-CoV-2 virus, analyzing patient serum samples. The antibody detection technique is a well-known indicator if the patient has been in contact with the virus and is considered the only valid test in asymptomatic patients. This chapter includes a description of required actuators, fluidics, and electronics to perform an automatic immunoassay. The established measurement format for the present biodetection platform was a direct immunoassay, using IgM/IgG antibodies in a serological sample, which comes in contact with the spike RBD domain immobilized on a Quartz Crystal Microbalance (QCM) surface. The biodetection platform can detect and quantify IgM+IgG antibodies in a concentration of 2.53μg L−1 and 17.88μg L−1, respectively. Moreover, the calculated sensitivity (I50) was 27.69μg L−1. The aforementioned analytical parameters are comparable with reports in which a QCM acoustic transducer was employed as an immunosensor for biosensing applications. © 2022 Elsevier Inc. All rights reserved.

Controversies in neuroimmunology: multiple sclerosis, vaccination, SARSCoV-2 and other dilemas

Neuroimmunology is a discipline that increasingly broadens its horizons in the understanding of neurological diseases. At the same time and in front of the pathophysiological links of neurological diseases and immunology, specific diagnostic and therapeutic approaches have been proposed. Despite the important advances in this discipline, there are multiple dilemmas that concern and filter into clinical practice. This article presents 15 controversies and a discussion about them, which are built with the most up-to-date evidence available. The topics included in this review are: steroid decline in relapses of multiple sclerosis (MS), therapeutic recommendations in MS in light of the SARS-CoV2 pandemic, evidence of vaccination in MS and other demyelinating diseases, overview current situation of isolated clinical and radiological syndrome, therapeutic failure in MS as well as criteria for suspension of disease-modifying therapies, evidence of the management of mild relapses in MS, recommendations for prophylaxis against strongyloides stercolaris, usefulness of a second course of immunoglobulin in the syndrome Guillain-Barre (GBS), criteria to differentiate an acute-onset inflammatory demyelinating chronic polyneuropathy versus GBS and the utility of angiotensin-converting enzyme in neurosarcoidosis. In each of the controversies, the general problem is presented and specific recommendations are offered that can be adopted in daily clinical practice.

Chapter 15 - Microfluidic-based biosensor for SARS-CoV-2 antibodies

This chapter addresses the basis for designing, prototyping, and developing a biosensing platform to support the control of the current global pandemic caused by the COVID-19 disease using an acoustic-based biosensor able to detect and quantify the IgM-and-IgG-specific antibodies against the spike protein (S) receptor-binding domain (RBD) from the SARS-CoV-2 virus, analyzing patient serum samples. The antibody detection technique is a well-known indicator if the patient has been in contact with the virus and is considered the only valid test in asymptomatic patients. This chapter includes a description of required actuators, fluidics, and electronics to perform an automatic immunoassay. The established measurement format for the present biodetection platform was a direct immunoassay, using IgM/IgG antibodies in a serological sample, which comes in contact with the spike RBD domain immobilized on a Quartz Crystal Microbalance (QCM) surface. The biodetection platform can detect and quantify IgM+IgG antibodies in a concentration of 2.53μg L−1 and 17.88μg L−1, respectively. Moreover, the calculated sensitivity (I50) was 27.69μg L−1. The aforementioned analytical parameters are comparable with reports in which a QCM acoustic transducer was employed as an immunosensor for biosensing applications.

Susceptible-Infected-Recovered model study using free particle dynamics

A study on the epidemiological Susceptible-Infected-Recovered (SIR) model is presented using free particle dynamics. The study is performed using a computational model consisting of randomly allocated particles in a closed domain which are free to move in random directions with the ability to collide with each other. The transmission rules for the particle-particle interactions are based on the main viral infection mechanisms, resulting in real-time results of the number of susceptible, infected, and recovered particles within a population of N = 200 particles. The results are qualitatively compared with a differential equation SIR model in terms of the transmission rate beta, recovery rate gamma, and the basic reproductive number R-0, yielding overall good results. The effect of the particle density rho(p) on R-0 is also studied to analyze how an infectious disease spreads over different types of populations. The versatility of the proposed free-particle-dynamics SIR model allows to simulate different scenarios, such as social distancing, commonly referred to as quarantine, no social distancing measures, and a mixture of the former and the latter. It is found that by implementing early relaxation of social distancing measures before the number of infected particles reaches zero, could lead to subsequent outbreaks such as the particular events observed in different countries due to the ongoing COVID-19 health crisis.

SARS-CoV-2 contact tracing among disadvantaged populations during epidemic intervals should be a priority strategy: results from a pilot experiment in Barcelona.

OBJECTIVES: The aim of this study was to trace contacts of coronavirus disease 2019 (COVID-19) hospitalised patients and determine the risk factors of infection in urban areas. STUDY DESIGN: Longitudinal analysis of contacts identified from index cases. METHODS: A contact tracing study was carried out in the Northern Metropolitan area of Barcelona, Spain, during the inter-epidemic lapse of May to July 2020, a period of low SARS-CoV-2 incidence. Index cases were notified from the referral hospital. Contacts were traced and followed up for 14 days. Reverse transcription polymerase chain reaction was performed on day 0 and day 14 for contacts. RESULTS: In total, 368 contacts were identified from 81 index cases (median of seven contacts per index case), from which 308 were traced successfully. The median age of contacts was 28 years, 62% (223 of 368) were men. During the follow-up period, 100 contacts tested positive for COVID-19 (32.5% [95% confidence interval {CI} = 27.3-38.0]), with a secondary infection rate of 48.3% (95% CI = 40.8-55.9) among housemates. Clusters of index and respective contacts tended to aggregate within disadvantaged neighbourhoods (P < 0.001), and non-national index cases (N = 28, 34.1%) resulted in higher secondary infection rates compared with nationals (51.0% [95% CI = 41.0-60.9] vs 22.3% [95% CI = 16.8-28.8]; P < 0.001). CONCLUSIONS: Disadvantaged communities experience a disproportionate burden of COVID-19 and may act as infection reservoirs. Contact tracing with a cross-cutting approach among these communities is required, especially during inter-epidemic periods.

Low Incidence and Mortality by SARS-CoV-2 Infection Among Healthcare Workers in a Health National Center in Mexico: Successful Establishment of an Occupational Medicine Program

Background: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Healthcare workers (HCWs) constitute a population which is significantly affected by SARS-CoV-2 infection worldwide. In Mexico, the Instituto Nacional de Enfermedades Respiratorias (INER) is the principal national reference of respiratory diseases. Aim: To evaluate the efficiency of the INER-POL-TRAB-COVID19 program to mitigate the SARS-CoV-2 infection risk among the INER-healthcare workers (INER-HCW). Methods: Currently, the INER has 250 beds and 200 respiratory ventilators to support COVID-19 patients in critical condition. On March 1st, 2020, the INER-POL-TRAB-COVID19 program was launched to mitigate the SARS-CoV-2 infection risk among the INER-HCW. Findings: From March 1st to October 1st, 2020, 71.5% of INER-HCWs were tested for SARS-CoV-2 infection, and 77% of them were frontline workers. Among the tested INER-HCWs, 10.4% were positive for SARS-CoV-2 infection. Nonetheless, nosocomial infection represented only 3.8% of the cases and the mortality was null. Fifty-three of INER-HCWs positive to SARS-CoV-2 had a negative test 42-56 days post-diagnosis and were returned to service. Finally, although a change in the PPE implemented on May 11th, 2020, the incidence of SARS-CoV-2 infection was not affected. Conclusion: INER has a lower incidence of HCWs infected with SARS-CoV-2 as compared to the mean of the national report. The implementation of the INER-POL-TRAB-COVID19 program is efficient to decrease the risk of infection among the HCWs. Our findings suggest that the implementation of a similar program at a national level can be helpful to provide a safe environment to HCWs and to prevent the collapse of health institutions.

The Bio-I Capsule. Preventing Contagion of Aerial Pathogens with Real-Time Reporting in Evalu@

During the current pandemic produced by Cov2, physicians and biologists have received attention. They have done a great job. However, these professionals help the already sick people who are, by now, less than 1% of the population. This tendency is an old conceptual mistake of medicine: we put more effort into curing than preventing. This sort of tradition-biasing directive explains why we are spending tons of resources curing people, while most of the global population remains unprotected. We need to set up our efforts to protect healthy people. They add to 99% of the current population. They are also the workforce that we need to re-activate the economies. We cannot hide forever, neither send our people to face an invisible enemy. As a response to the question: how can we prevent contagion efficiently? We have created the bio-I capsule to bring back the crowd’s confidence so they can develop their lives and re-activate the economy. We are facing a retrovirus. The last pathogen of this kind was HIV announced in 1986. HIV is still there because creating a vaccine to fight is not straightforward. While attacking the retrovirus, we also compromise fundamental cell functions. For our sake, we shall assume that Cov2 will remain there longer than expected. Recall also that pathogens are potent when they are inside the hosts’ bodies. Nevertheless, if we keep them outside, they will get denaturalized easily. An effective strategy to avoid contamination will also kill the current menace and any other pathogen coming in the future. The Bio-I capsule is an effective barrier against nanoscopic pathogens, and this manuscript presents details of its specifications and constructions along with the scientific reasons for its creation. © 2020, Springer Nature Switzerland AG.