Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78.475
Filtrar
2.
Orv Hetil ; 162(15): 563-570, 2021 04 02.
Artículo en Húngaro | MEDLINE | ID: mdl-33798101

RESUMEN

Összefoglaló. A koronavírus-betegség 2019 (COVID-19)-pandémia komoly kihívás elé állította nemcsak a mikrobiológiai laboratóriumokat, hanem az eredmények interpretálásában a klinikumban dolgozó kollégákat is. Az orvostudomány specializált világában az immunológiai és a fertozo betegségekkel kapcsolatos ismeretek az antimikrobás terápiás megoldások sikeressége, valamint a széles köru vakcináció miatt az idok folyamán számos szakterületen háttérbe szorultak, felfrissítésük sürgeto és elengedhetetlen része a pandémiával való megküzdésnek. A diagnosztikai vizsgálatok fontos eszközei a járvány megfékezésének, illetve a betegek ellátásának, azonban a vírus és az emberi szervezet interakciójának megértése elengedhetetlenül szükséges a korrekt epidemiológiai és gyógyászati véleményalkotáshoz. Jelen cikkünk az orvosi gyakorlat számára foglalja össze a súlyos akut légzoszervi szindrómát okozó koronavírus-2 (SARS-CoV-2) kimutatására, valamint az immunrendszer specifikus immunválaszának szerológiai vizsgálatára irányuló, gyakorlatban használatos módszereket, azok helyét, szerepét és értékelésük szempontjait a tudomány jelen állása szerint. Orv Hetil. 2021; 162(15): 563-570. Summary. The coronavirus disease 2019 (COVID-19) pandemic posed a serious challenge not only for microbiology laboratories, but also for the clinicians in interpretation of the results. In the specialized world of medicine, knowledge of immunological and infectious diseases has been relegated to the background in many disciplines over time due to the success of antimicrobial therapies and widespread vaccination, so updating them is an urgent and essential part of the fight against the pandemic. Diagnostic tests are important tools for controlling the epidemic and caring for patients, but understanding the interaction between the virus and the human body is essential to form a correct epidemiological and medical opinion. This paper summarizes the medical methods for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the serological testing of the specific immune response of the immune system, their place, role and criteria of their evaluation according to current scientific knowledge. Orv Hetil. 2021; 162(15): 563-570.


Asunto(s)
Anticuerpos Antivirales , Antígenos Virales , Anticuerpos Antivirales/aislamiento & purificación , Antígenos Virales/aislamiento & purificación , Humanos , /inmunología
3.
Front Immunol ; 12: 614436, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33790892

RESUMEN

The novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic of the coronavirus disease 2019 (COVID-19), which elicits a wide variety of symptoms, ranging from mild to severe, with the potential to lead to death. Although used as the standard method to screen patients for SARS-CoV-2 infection, real-time PCR has challenges in dealing with asymptomatic patients and those with an undetectable viral load. Serological tests are therefore considered potent diagnostic tools to complement real-time PCR-based diagnosis and are used for surveillance of seroprevalence in populations. However, the dynamics of the antibody response against SARS-CoV-2 currently remain to be investigated. Here, through analysis of plasma samples from 84 patients with COVID-19, we observed that the response of virus-specific antibodies against three important antigens, RBD, N and S, dynamically changed over time and reached a peak 5-8 weeks after the onset of symptoms. The antibody responses were irrespective of sex. Severe cases were found to have higher levels of antibody response, larger numbers of inflammatory cells and C-reactive protein levels. Within the mild/moderate cases, pairwise comparison indicated moderate association between anti-RBD vs. anti-N, anti-RBD vs. anti-S1S2, and anti-N vs. anti-S1S2. Furthermore, the majority of cases could achieve IgM and IgG seroconversion at 2 weeks since the disease onset. Analysis of neutralizing antibodies indicated that these responses were able to last for more than 112 days but decline significantly after the peak. In summary, our findings demonstrate the longitudinally dynamic changes in antibody responses against SARS-CoV-2, which can contribute to the knowledge of humoral immune response after SARS-CoV-2 infection and are informative for future development of vaccine and antibody-based therapies.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , /inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Beijing , China , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Fosfoproteínas/inmunología , Dominios Proteicos/inmunología , Seroconversión , Índice de Severidad de la Enfermedad , Centros de Atención Terciaria
4.
BMJ Open ; 11(4): e045425, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795310

RESUMEN

OBJECTIVES: We aimed to review SARS-CoV-2 seroprevalence studies conducted in Europe to understand how they may be used to inform ongoing control strategies for COVID-19. DESIGN: Scoping review of peer-reviewed publications and manuscripts on preprint servers from January 2020 to 15 September 2020. PRIMARY MEASURE: Seroprevalence estimate (and lower and upper CIs). For studies conducted across a country or territory, we used the seroprevalence estimate and the upper and lower CIs and compared them to the total number of reported infections to calculate the ratio of reported to expected infections. RESULTS: We identified 23 population-based seroprevalence studies conducted in Europe. Among 12 general population studies, seroprevalence ranged from 0.42% among residual clinical samples in Greece to 13.6% in an area of high transmission in Gangelt, Germany. Of the eight studies in blood donors, seroprevalence ranged from 0.91% in North-Western Germany to 23.3% in a high-transmission area in Lombardy region, Italy. In three studies which recruited individuals through employment, seroprevalence ranged from 0.5% among factory workers in Frankfurt, Germany, to 10.2% among university employees in Milan, Italy. In comparison to nationally reported cases, the extent of infection, as derived from these seroprevalence estimates, is manyfold higher and largely heterogeneous. CONCLUSION: Exposure to the virus in Europe has not reached a level of infection that would prevent further circulation of the virus. Effective vaccine candidates are urgently required to deliver the level of immunity in the population.


Asunto(s)
Anticuerpos Antivirales/sangre , Estudios Seroepidemiológicos , /sangre , Europa (Continente)/epidemiología , Alemania , Grecia , Humanos , Italia , Pandemias
5.
Science ; 372(6537)2021 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-33795432

RESUMEN

Multivalent display of receptor-engaging antibodies or ligands can enhance their activity. Instead of achieving multivalency by attachment to preexisting scaffolds, here we unite form and function by the computational design of nanocages in which one structural component is an antibody or Fc-ligand fusion and the second is a designed antibody-binding homo-oligomer that drives nanocage assembly. Structures of eight nanocages determined by electron microscopy spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage, respectively, closely match the corresponding computational models. Antibody nanocages targeting cell surface receptors enhance signaling compared with free antibodies or Fc-fusions in death receptor 5 (DR5)-mediated apoptosis, angiopoietin-1 receptor (Tie2)-mediated angiogenesis, CD40 activation, and T cell proliferation. Nanocage assembly also increases severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus neutralization by α-SARS-CoV-2 monoclonal antibodies and Fc-angiotensin-converting enzyme 2 (ACE2) fusion proteins.


Asunto(s)
Anticuerpos/química , Anticuerpos/inmunología , Nanoestructuras , Ingeniería de Proteínas , Transducción de Señal , Angiopoyetinas/química , Angiopoyetinas/inmunología , Angiopoyetinas/metabolismo , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , Antígenos CD40/química , Antígenos CD40/inmunología , Antígenos CD40/metabolismo , Línea Celular Tumoral , Proliferación Celular , Simulación por Computador , Genes Sintéticos , Humanos , Fragmentos Fc de Inmunoglobulinas/química , Activación de Linfocitos , Modelos Moleculares , Unión Proteica , Receptor TIE-2/metabolismo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/inmunología , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Linfocitos T/inmunología , Linfocitos T/fisiología
6.
Medicina (Kaunas) ; 57(3)2021 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-33804646

RESUMEN

Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests' results on samples from the upper respiratory tract.


Asunto(s)
/diagnóstico , Heces/química , Pulmón/diagnóstico por imagen , Nasofaringe/química , Orofaringe/química , ARN Viral/aislamiento & purificación , Adulto , Anticuerpos Antivirales/inmunología , Reacciones Falso Negativas , Heces/virología , Humanos , Inmunoglobulina M/inmunología , Masculino , Nasofaringe/virología , Orofaringe/virología , Manejo de Especímenes , Tomografía Computarizada por Rayos X
7.
Artículo en Inglés | MEDLINE | ID: mdl-33804893

RESUMEN

BACKGROUND: Healthcare workers (HCWs) have been the key players in the fight against the coronavirus disease 2019 (COVID-19) pandemic. The aim of our study was to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG anti-bodies. METHODS: We conducted a cross-sectional study among workers of two hospitals and Territorial Medical and Administrative services in Northern Italy. From 8 May to 3 June 2020, 2252 subjects were tested. Seroprevalence and 95% confidence interval (CI) were calculated for all individuals who were stratified by job title, COVID-19 risk of exposure, direct contact with patients, unit ward, and intensity of care. RESULTS: Median age was 50 years, and 72% of subjects were female. The overall seroprevalence was 17.11% [95% CI 15.55-18.67]. Around 20% of healthcare assistants were seropositive, followed by physicians and nurses (16.89% and 15.84%, respectively). HCWs with high risk of exposure to COVID-19 were more frequently seropositive (28.52%) with respect to those with medium and low risks (16.71% and 12.76%, respectively). Moreover, personnel in direct contact had higher prevalence (18.32%) compared to those who did not (10.66%). Furthermore, the IgG were more frequently detected among personnel of one hospital (19.43%). CONCLUSION: The high seroprevalence observed can be partially explained by the timing and the population seroprevalence; the study was conducted in an area with huge spread of the infection.


Asunto(s)
Anticuerpos Antivirales , Estudios Transversales , Femenino , Personal de Salud , Hospitales , Humanos , Italia/epidemiología , Persona de Mediana Edad , Estudios Seroepidemiológicos
8.
Artículo en Inglés | MEDLINE | ID: mdl-33805139

RESUMEN

Coronavirus disease 2019 (COVID-19) is an acute infectious disease caused by the novel coronavirus (SARS-CoV-2) identified in 2019. The COVID-19 outbreak continues to have devastating consequences for human lives and the global economy. The B-LiFe mobile laboratory in Piedmont, Italy, was deployed for the surveillance of COVID-19 cases by large-scale testing of first responders. The objective was to assess the seroconversion among the regional civil protection (CP), police, health care professionals, and volunteers. The secondary objective was to detect asymptomatic individuals within this cohort in the light of age, sex, and residence. In this paper, we report the results of serological testing performed by the B-LiFe mobile laboratory deployed from 10 June to 23 July 2020. The tests included whole blood finger-prick and serum sampling for detection of SARS-CoV-2 spike receptor-binding domain (S-RBD) antibodies. The prevalence of SARS-CoV-2 antibodies was approximately 5% (294/6013). The results of the finger-prick tests and serum sample analyses showed moderate agreement (kappa = 0.77). Furthermore, the detection rates of serum antibodies to the SARS-CoV-2 nucleocapsid protein (NP) and S-RBD among the seroconverted individuals were positively correlated (kappa = 0.60), at least at the IgG level. Seroprevalence studies based on serological testing for the S-RBD protein or SARS-CoV-2 NP antibodies are not sufficient for diagnosis but might help in screening the population to be vaccinated and in determining the duration of seroconversion.


Asunto(s)
Laboratorios , Anticuerpos Antivirales , Humanos , Inmunoglobulina G , Inmunoglobulina M , Italia/epidemiología , Estudios Seroepidemiológicos
10.
Euro Surveill ; 26(13)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33797390

RESUMEN

BackgroundChildren have a low rate of COVID-19 and secondary severe multisystem inflammatory syndrome (MIS) but present a high prevalence of symptomatic seasonal coronavirus infections.AimWe tested if prior infections by seasonal coronaviruses (HCoV) NL63, HKU1, 229E or OC43 as assessed by serology, provide cross-protective immunity against SARS-CoV-2 infection.MethodsWe set a cross-sectional observational multicentric study in pauci- or asymptomatic children hospitalised in Paris during the first wave for reasons other than COVID (hospitalised children (HOS), n = 739) plus children presenting with MIS (n = 36). SARS-CoV-2 antibodies directed against the nucleoprotein (N) and S1 and S2 domains of the spike (S) proteins were monitored by an in-house luciferase immunoprecipitation system assay. We randomly selected 69 SARS-CoV-2-seropositive patients (including 15 with MIS) and 115 matched SARS-CoV-2-seronegative patients (controls (CTL)). We measured antibodies against SARS-CoV-2 and HCoV as evidence for prior corresponding infections and assessed if SARS-CoV-2 prevalence of infection and levels of antibody responses were shaped by prior seasonal coronavirus infections.ResultsPrevalence of HCoV infections were similar in HOS, MIS and CTL groups. Antibody levels against HCoV were not significantly different in the three groups and were not related to the level of SARS-CoV-2 antibodies in the HOS and MIS groups. SARS-CoV-2 antibody profiles were different between HOS and MIS children.ConclusionPrior infection by seasonal coronaviruses, as assessed by serology, does not interfere with SARS-CoV-2 infection and related MIS in children.


Asunto(s)
Anticuerpos Antivirales/inmunología , Coronavirus Humano OC43 , Síndrome de Respuesta Inflamatoria Sistémica , Adolescente , Anticuerpos Antivirales/sangre , /diagnóstico , Niño , Preescolar , Estudios Transversales , Femenino , Francia/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Paris , Estaciones del Año , Pruebas Serológicas/métodos , Glicoproteína de la Espiga del Coronavirus
11.
BMC Infect Dis ; 21(1): 325, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33827460

RESUMEN

BACKGROUND: Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. METHODS: Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. RESULTS: Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78-100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. CONCLUSIONS: The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.


Asunto(s)
Anticuerpos Antivirales/sangre , Formación de Anticuerpos , /inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Humanos , Immunoblotting , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Pandemias , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Seroconversión , Pruebas Serológicas
12.
J Transl Med ; 19(1): 132, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33789686

RESUMEN

Coronavirus disease 2019 (COVID-19) global pandemic has created unique challenges to healthcare systems throughout the world. Ensuring subjects' safety is mandatory especially in oncology, in consideration of cancer patients' particular frailty. We examined the proportion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgM and/or IgG positive subjects in three different groups from Istituto Nazionale Tumori - IRCCS "Fondazione G. Pascale" in Naples (Campania region, Italy): cancer patients treated with Innovative Immunotherapy (Immune Checkpoint Inhibitors, ICIs), cancer patients undergoing standard Chemotherapies (CHTs) and healthcare providers. 9 out of 287 (3.1%) ICIs patients resulted positive, with a significant lower percentage in respect to CHTs patients (39 positive subjects out of 598, 6.5%) (p = 0.04). There was no statistically significant difference between ICIs cohort and healthcare providers, 48 out of 1050 resulting positive (4.6%). Performing a Propensity Score Matching based on gender and tumor stage, the effect of treatment on seropositivity was analyzed through a regression logistic model and the ICIs treatment resulted to be the only protective factor significantly (p = 0.03) associated with positivity (odds ratio-OR: 0.41; 95% confidence interval-CI 0.18-0.91). According to these preliminary data, ICIs would appear to be a protective factor against the onset of COVID-19 infection.


Asunto(s)
/prevención & control , Inmunoterapia , Neoplasias/terapia , Anciano , Anticuerpos Antivirales/sangre , Antineoplásicos/uso terapéutico , /inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Italia/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/inmunología , Pandemias , Estudios Retrospectivos , Investigación en Medicina Traslacional
13.
Artículo en Inglés | MEDLINE | ID: mdl-33800721

RESUMEN

Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test's predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress.


Asunto(s)
Anticuerpos Antivirales , Personal de Salud , Hospitales , Humanos , Roma , Estudios Seroepidemiológicos , Pruebas Serológicas
14.
Artículo en Inglés | MEDLINE | ID: mdl-33806578

RESUMEN

Sero-epidemiological surveys are valuable attempts to estimate the circulation of SARS-CoV-2 in general or selected populations. Within this context, a prospective observational study was conducted to estimate the prevalence and persistence of SARS-CoV-2 antibodies in different categories of workers and factors associated with positivity, through the detection of virus-specific immunoglobulin G and M (IgG/IgM) in serum samples. Enrollees were divided in low exposure and medium-high groups on the basis of their work activity. Antibody responders were re-contacted after 3 months for the follow-up. Of 2255 sampled workers, 4.8% tested positive for SARS-CoV-2 IgG/IgM antibodies, with 81.7% to IgG only. Workers who continued to go to their place of work, were healthcare workers, or experienced at least one COVID-19-related symptom were more likely to test positive for SARS-CoV-2 antibodies. SARS-CoV-2 antibodies prevalence was significantly higher in the medium-high risk vs. low-risk group (7.2% vs. 3.0%, p < 0.0001). At 3-month follow-up, 81.3% of subjects still had antibody response. This study provided important information of SARS-CoV-2 infection prevalence among workers in northern Italy, where the impact of COVID-19 was particularly intense. The presented surveillance data give a contribution to refine current estimates of the disease burden expected from the SARS-CoV-2.


Asunto(s)
Exposición Profesional , Anticuerpos Antivirales , Humanos , Italia/epidemiología , Ocupaciones
15.
Artículo en Inglés | MEDLINE | ID: mdl-33806642

RESUMEN

After the first pandemic wave, a nationwide survey assessed the seroprevalence of SARS-CoV-2 antibodies in Spain and found notable differences among provinces whose causes remained unclear. This ecological study aimed to analyze the association between environmental and demographic factors and SARS-CoV-2 infection by province. The seroprevalence of SARS-CoV-2 antibodies by province was obtained from a nationwide representative survey performed in June 2020, after the first pandemic wave in Spain. Linear regression was used in the analysis. The seroprevalence of SARS-CoV-2 antibodies of the 50 provinces ranged from 0.2% to 13.6%. The altitude, which ranged from 5 to 1131 m, explained nearly half of differences in seroprevalence (R2 = 0.47, p < 0.001). The seroprevalence in people residing in provinces above the median altitude (215 m) was three-fold higher (6.5% vs. 2.1%, p < 0.001). In the multivariate linear regression, the addition of population density significantly improved the predictive value of the altitude (R2 = 0.55, p < 0.001). Every 100 m of altitude increase and 100 inhabitants/km2 of increase in population density, the seroprevalence rose 0.84 and 0.63 percentage points, respectively. Environmental conditions related to higher altitude in winter-spring, such as lower temperatures and absolute humidity, may be relevant to SARS-CoV-2 transmission. Places with such adverse conditions may require additional efforts for pandemic control.


Asunto(s)
Altitud , Anticuerpos Antivirales , Humanos , Inmunoglobulina G , Pandemias , Estudios Seroepidemiológicos , España/epidemiología
16.
Artículo en Inglés | MEDLINE | ID: mdl-33808716

RESUMEN

Lack of knowledge around seroprevalence levels of COVID-19 in Poland was the reason for the implementation of a seroepidemiological study in the Katowice Region (2,100,000 inhabitants). In October-November 2020, a questionnaire examination and measurement of anti-SARS-CoV-2 IgG and IgM antibodies were performed in a random sample of the general population (n = 1167). The objectives of the study were to estimate the prevalence of IgG and IgM antibodies and to assess their host-related correlates. The prevalence of IgG seropositivity was 11.4% (95% CI: 9.5-13.2%) and IgM seropositivity was 4.6% (95% CI: 3.5-5.8%). Diagnosis of COVID-19 was found in 4.8% of subjects. A positive IgG test was statistically significantly associated with age (inverse relationship), a person's contact with a COVID-19 patient, quarantine, and two symptoms in the past: fever and loss of smell/taste. Positive IgG tests were less prevalent in subjects who had diagnoses of arterial hypertension, diabetes, or rheumatologic disorders. IgM test positivity was associated with quarantine and loss of smell/taste only with no effect of chronic diseases found. In Poland, in the period October-November 2020, the prevalence of SARS-CoV-2 infection was larger than earlier estimates obtained in other European countries, probably reflecting the measurements obtained during the "second wave" of the epidemic.


Asunto(s)
Anticuerpos Antivirales , Europa (Continente) , Humanos , Inmunoglobulina M , Polonia/epidemiología , Estudios Seroepidemiológicos
17.
PLoS One ; 16(4): e0238088, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33793556

RESUMEN

BACKGROUND: COVID-19 seroprevalence data, particularly in less developed countries with a relatively low incidence, has been scant. We aimed to explore the seroprevalence of hospital staff in the area with zero confirmed COVID-19 case to shed light on the situation of COVID-19 infection in zero or low infection rate countries where mass screening was not readily available. METHODS: A locally developed rapid immunoglobulin M (IgM)/immunoglobulin G (IgG) test kit was used for hospital staff screening of Ranong hospital which is located in a province with zero COVID-19 prevalence in Thailand from 17th April to 17th May 2020. All staff was tested, 100 of which were randomly invited to have a repeating antibody test in one month. (Thai Clinical Trials Registry: TCTR20200426002). RESULTS: Of 844 hospital staff, 82 were tested twice one month apart (response rate for repeating antibody test 82%). Overall, 0.8% of the participants (7 of 844) had positive IgM, none had positive IgG. Female staff had 1.0% positive IgM (95% CI: 0.5-2.1%) while male had 0.5% positive IgM (95% CI: 0.1-2.6%). No participants with a history of travel to the high-risk area or close contact with PCR-confirmed COVID-19 case developed SARS-CoV-2 antibodies. Among 844 staff, 811 had no symptoms and six of them developed IgM seropositive (0.7%) while 33 had minor symptoms and only one of them developed IgM seropositive (3.0%). No association between SARS-CoV-2 IgM status and gender, history of travel to a high-risk area, close contact with PCR-confirmed or suspected COVID-19 case, presence of symptoms within 14 days, or previous PCR status was found. None of the hospital staff developed SARS-CoV-2 IgG. CONCLUSIONS: COVID-19 antibody test could detect a considerable number of hospital staff who could be potential silent spreaders in a province with zero COVID-19 cases. Accurate antibody testing is a valuable screening tool, particularly in asymptomatic healthcare workers. Trial registration: This study was approved by the Institutional Review Board of Chulalongkorn University (IRB No.236/63) and the Institutional Review Board of Ranong Hospital. (Thai Clinical Trials Registry: TCTR20200426002).


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Personal de Hospital/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Tailandia/epidemiología
18.
PLoS One ; 16(4): e0249550, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33793673

RESUMEN

Data on the prevalence of the SARS-CoV-2 antibody in healthcare workers (HCWs) is scarce, especially in pediatric settings. The purpose of this study was to evaluate SARS-CoV-2 IgG-positivity among HCWs of a tertiary pediatric hospital. In addition, follow-up of the serological response in the subgroup of seropositive HCWs was analysed, to gain some insight on the persistence of IgG antibodies to SARS-CoV-2. We performed a retrospective analysis of voluntary SARS-CoV-2 IgG testing, which was made available free of charge to HCWs of the Children's Memorial Health Institute in Warsaw (Poland). Plasma samples were collected between July 1 and August 9, 2020, and tested using the Abbott SARS-CoV-2 IgG assay. Of 2,282 eligible participants, 1,879 (82.3%) HCWs volunteered to undergo testing. Sixteen HCWs tested positive for SARS-CoV-2 IgG, corresponding to a seroprevalence of 0.85%. Among seropositive HCWs, three HCWs had confirmed COVID-19. Nine (56.3%) of the seropositive HCWs reported neither symptoms nor unprotected contact with confirmed SARS-CoV-2 cases in the previous months. A decline in the IgG index was observed at a median time of 86.5 days (range:84‒128 days) after symptom onset or RT-PCR testing. Further studies are necessary to elucidate the duration of persistence of anti-SARS-CoV-2 antibodies, as well as the correlation between seropositivity and protective immunity against reinfection. Regardless of the persistence of antibodies and their protective properties, such low prevalence indicates that this population is vulnerable to a second wave of the COVID-19 pandemic.


Asunto(s)
Anticuerpos Antivirales/sangre , Personal de Salud/estadística & datos numéricos , Inmunoglobulina G/sangre , /inmunología , Adulto , /inmunología , Femenino , Hospitales Pediátricos/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Polonia , Prevalencia , Estudios Retrospectivos , Estudios Seroepidemiológicos , Centros de Atención Terciaria/estadística & datos numéricos
19.
Nat Commun ; 12(1): 2037, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795692

RESUMEN

The hallmarks of COVID-19 are higher pathogenicity and mortality in the elderly compared to children. Examining baseline SARS-CoV-2 cross-reactive immunological responses, induced by circulating human coronaviruses (hCoVs), is needed to understand such divergent clinical outcomes. Here we show analysis of coronavirus antibody responses of pre-pandemic healthy children (n = 89), adults (n = 98), elderly (n = 57), and COVID-19 patients (n = 50) by systems serology. Moderate levels of cross-reactive, but non-neutralizing, SARS-CoV-2 antibodies are detected in pre-pandemic healthy individuals. SARS-CoV-2 antigen-specific Fcγ receptor binding accurately distinguishes COVID-19 patients from healthy individuals, suggesting that SARS-CoV-2 infection induces qualitative changes to antibody Fc, enhancing Fcγ receptor engagement. Higher cross-reactive SARS-CoV-2 IgA and IgG are observed in healthy elderly, while healthy children display elevated SARS-CoV-2 IgM, suggesting that children have fewer hCoV exposures, resulting in less-experienced but more polyreactive humoral immunity. Age-dependent analysis of COVID-19 patients, confirms elevated class-switched antibodies in elderly, while children have stronger Fc responses which we demonstrate are functionally different. These insights will inform COVID-19 vaccination strategies, improved serological diagnostics and therapeutics.


Asunto(s)
Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , /inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , /inmunología , Niño , Preescolar , Reacciones Cruzadas/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Persona de Mediana Edad , Receptores de IgG/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto Joven
20.
PLoS One ; 16(4): e0248946, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33798211

RESUMEN

BACKGROUND: Accurate seroprevalence estimates of SARS-CoV-2 in different populations could clarify the extent to which current testing strategies are identifying all active infection, and hence the true magnitude and spread of the infection. Our primary objective was to identify valid seroprevalence studies of SARS-CoV-2 infection and compare their estimates with the reported, and imputed, COVID-19 case rates within the same population at the same time point. METHODS: We searched PubMed, Embase, the Cochrane COVID-19 trials, and Europe-PMC for published studies and pre-prints that reported anti-SARS-CoV-2 IgG, IgM and/or IgA antibodies for serosurveys of the general community from 1 Jan to 12 Aug 2020. RESULTS: Of the 2199 studies identified, 170 were assessed for full text and 17 studies representing 15 regions and 118,297 subjects were includable. The seroprevalence proportions in 8 studies ranged between 1%-10%, with 5 studies under 1%, and 4 over 10%-from the notably hard-hit regions of Gangelt, Germany; Northwest Iran; Buenos Aires, Argentina; and Stockholm, Sweden. For seropositive cases who were not previously identified as COVID-19 cases, the majority had prior COVID-like symptoms. The estimated seroprevalences ranged from 0.56-717 times greater than the number of reported cumulative cases-half of the studies reported greater than 10 times more SARS-CoV-2 infections than the cumulative number of cases. CONCLUSIONS: The findings show SARS-CoV-2 seroprevalence is well below "herd immunity" in all countries studied. The estimated number of infections, however, were much greater than the number of reported cases and deaths in almost all locations. The majority of seropositive people reported prior COVID-like symptoms, suggesting that undertesting of symptomatic people may be causing a substantial under-ascertainment of SARS-CoV-2 infections.


Asunto(s)
Anticuerpos Antivirales/sangre , Isotipos de Inmunoglobulinas/sangre , Adolescente , Adulto , Anciano , Argentina , /inmunología , Femenino , Alemania , Humanos , Inmunidad Colectiva , Incidencia , Irán , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Suecia , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...