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1.
Washington, D.C.; PAHO; 2020-10-14. (PAHO/CDE/VT/20-0035).
em Inglês | PAHO-IRIS | ID: phr-52839

RESUMO

In 2016, the Pan American Health Organization, in partnership with the U.S. Centers for Disease Control and Prevention, began a collaborative effort with delegates from Brazil, Mexico, and Paraguay aimed at transferring technical capacity for integrated serological surveillance of population immunity and transmission of multiple infectious diseases, using the multiplex bead assay (MBA) platform. MBA makes it possible to analyze the antibodies of up to 96 antigens of various pathogens in a single dried-spot blood sample. Serological surveillance is being increasingly used for its ability to generate information that helps characterize disease transmission and monitor the impact of interventions such as vaccination, and to identify susceptible populations. This initiative has served as a learning process based on interprogrammatic work to develop integrated serological surveillance of various diseases and events that are often addressed separately from a programmatic standpoint, but which in reality overlap in the same population groups and geographical areas. This document presents the results of the third regional meeting, held in the city of Cuernavaca, Mexico, on 4-5 March 2020, and attended by delegates from the participating countries, partners, and stakeholders. This publication highlights the lessons learned during the first stage of capacity transfer, and discusses opportunities and next steps to expand integrated serological surveillance in the Region of the Americas as a tool for strengthening surveillance of communicable diseases.


Assuntos
Doenças Transmissíveis , América , Testes Sorológicos , Vigilância , Doenças Negligenciadas , Epidemiologia , Serviços de Vigilância Epidemiológica , Betacoronavirus
2.
BMC Pregnancy Childbirth ; 20(1): 580, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008308

RESUMO

BACKGROUND: During the ongoing global outbreak of COVID-19, pregnant women who are susceptible to COVID-19 should be highly concerned. The issue of vertical transmission and the possibility of neonatal infection is a major concern. CASE PRESENTATION: Case 1: A 35-year-old pregnant woman with a gestational age of 37 weeks and 6 days was admitted to our hospital at the point of giving birth. Except for the abnormalities in her chest CT image, she was asymptomatic. She had an uncomplicated spontaneous vaginal delivery, and her infant was discharged home for isolation. Because of the positive result of the maternal swabs for SARS-CoV-2 obtained on the 2nd day after sampling, we transferred the mother to the designated hospital and followed up with her by telephone interviews. Luckily, it was confirmed on February 23 that the newborn did not develop any COVID-19 symptoms after observation for 14 days after birth. Case 2: Another pregnant woman, with a gestational age of 38 weeks and 2 days, was also admitted to our hospital because of spontaneous labor with cervical dilation of 5 cm. Since she had the typical manifestations of COVID-19, including cough, lymphopenia, and abnormal chest CT images, she was highly suspected of having COVID-19. Based on the experience from case 1, we helped the mother deliver a healthy baby by vaginal delivery. On the 2nd day after delivery, the maternal nasopharyngeal swab result was positive, while the infant's result was negative. CONCLUSION: There is still insufficient evidence supporting maternal-fetal vertical transmission for COVID-19-infected mothers in late pregnancy, and vaginal delivery may not increase the possibility of neonatal infection.


Assuntos
Infecções Assintomáticas , Infecções por Coronavirus/diagnóstico , Parto Obstétrico/métodos , Pulmão/diagnóstico por imagem , Pneumonia Viral/diagnóstico , Complicações Infecciosas na Gravidez/diagnóstico , Adulto , Antibacterianos/uso terapêutico , Antivirais/uso terapêutico , Betacoronavirus , Aleitamento Materno , Técnicas de Laboratório Clínico , Infecções por Coronavirus/terapia , Tosse , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Idade Gestacional , Humanos , Linfopenia , Máscaras , Oxigenoterapia , Pandemias , Isolamento de Pacientes , Equipamento de Proteção Individual , Pneumonia Viral/terapia , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/terapia , Testes Sorológicos , Tomografia Computadorizada por Raios X
3.
Am J Case Rep ; 21: e927812, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33009361

RESUMO

BACKGROUND This is a case report of an immunocompromised patient with a history of non-Hodgkin lymphoma and persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who was seronegative and successfully treated with convalescent plasma. CASE REPORT A 63-year-old woman with a past medical history of non-Hodgkin lymphoma in remission while on maintenance therapy with the anti-CD20 monoclonal antibody, obinutuzumab, tested positive for SARS-CoV-2 via nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) testing over 12 weeks and persistently tested seronegative for immunoglobulin G (IgG) antibodies using SARS-CoV-2 IgG chemiluminescent microparticle immunoassay technology. During this time, the patient experienced waxing and waning of symptoms, which included fever, myalgia, and non-productive cough, but never acquired severe respiratory distress. She was admitted to our hospital on illness day 88, and her symptoms resolved after the administration of convalescent plasma. CONCLUSIONS As the understanding of the pathogenesis of SARS-CoV-2 continues to evolve, we can currently only speculate about the occurrence of chronic infection vs. reinfection. The protective role of antibodies and their longevity against SARS-CoV-2 remain unclear. Since humoral immunity has an integral role in SARS-CoV-2 infection, various phase 3 vaccine trials are underway. In the context of this pandemic, the present case demonstrates the challenges in our understanding of testing and treating immunocompromised patients.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Hospedeiro Imunocomprometido , Linfoma não Hodgkin/imunologia , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Antineoplásicos Imunológicos/administração & dosagem , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/terapia , Feminino , Seguimentos , Humanos , Imunização Passiva/métodos , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/tratamento farmacológico , Pessoa de Meia-Idade , Pandemias , Reação em Cadeia da Polimerase em Tempo Real/métodos , Testes Sorológicos/métodos , Índice de Gravidade de Doença , Resultado do Tratamento
4.
mSphere ; 5(5)2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938700

RESUMO

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Here, we present an efficient, competitive serological assay that can simultaneously determine an individual's seroreactivity against the SARS-CoV-2 Spike protein and determine the proportion of anti-Spike antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. In this approach based on the use of enzyme-linked immunosorbent assays (ELISA), we present natively folded viral Spike protein receptor-binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then competed with soluble ACE2-Fc, or with a higher-affinity variant thereof, to determine the proportion of ACE2 blocking anti-RBD antibodies. Assessment of sera from 144 SARS-CoV-2 patients ultimately revealed that a remarkably consistent and high proportion of antibodies in the anti-RBD pool targeted the epitope responsible for ACE2 engagement (83% ± 11%; 50% to 107% signal inhibition in our largest cohort), further underscoring the importance of tailoring vaccines to promote the development of such antibodies.IMPORTANCE With the emergence and continued spread of the SARS-CoV-2 virus, and of the associated disease, coronavirus disease 2019 (COVID-19), there is an urgent need for improved understanding of how the body mounts an immune response to the virus. Here, we developed a competitive SARS-CoV-2 serological assay that can simultaneously determine whether an individual has developed antibodies against the SARS-CoV-2 Spike protein receptor-binding domain (RBD) and measure the proportion of these antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. Using this assay and 144 SARS-CoV-2 patient serum samples, we found that a majority of anti-RBD antibodies compete for ACE2 binding. These results not only highlight the need to design vaccines to generate such blocking antibodies but also demonstrate the utility of this assay to rapidly screen patient sera for potentially neutralizing antibodies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Peptidil Dipeptidase A/imunologia , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Antígenos Virais/imunologia , Sítios de Ligação/imunologia , Infecções por Coronavirus/prevenção & controle , Ensaios de Triagem em Larga Escala/métodos , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Ligação Proteica , Domínios Proteicos/imunologia
5.
Emerg Microbes Infect ; 9(1): 2157-2168, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32940547

RESUMO

This multicenter, retrospective study included 346 serum samples from 74 patients with coronavirus disease 2019 (COVID-19) and 194 serum samples from non-COVID-19 patients to evaluate the performance of five anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests, i.e. two chemiluminescence immunoassays (CLIAs): Roche Elecsys® Anti-SARS-CoV-2 Test (Roche Test) and Abbott SARS-CoV-2 IgG (Abbott Test), and three lateral flow immunoassays (LFIAs): Wondfo SARS-CoV-2 Antibody Test (Wondfo Test), ASK COVID-19 IgG/IgM Rapid Test (ASK Test), and Dynamiker 2019-nCoV IgG/IgM Rapid Test (Dynamiker Test). We found high diagnostic sensitivities (%, 95% confidence interval [CI]) for the Roche Test (97.4%, 93.4-99.0%), Abbott Test (94.0%, 89.1-96.8%), Wondfo Test (91.4%, 85.8-94.9%), ASK Test (97.4%, 93.4-99.0%), and Dynamiker Test (90.1%, 84.3-94.0%) after >21 days of symptom onset. Meanwhile, the diagnostic specificity was 99.0% (95% CI, 96.3-99.7%) for the Roche Test, 97.9% (95% CI, 94.8-99.2%) for the Abbott Test, and 100.0% (95% CI, 98.1-100.0%) for the three LFIAs. Cross-reactivity was observed in sera containing anti-cytomegalovirus (CMV) IgG/IgM antibodies and autoantibodies. No difference was observed in the time to seroconversion detection of the five serological tests. Specimens from patients with COVID-19 pneumonia demonstrated a shorter seroconversion time and higher chemiluminescent signal than those without pneumonia. Our data suggested that understanding the dynamic antibody response after COVID-19 infection and performance characteristics of different serological test are crucial for the appropriate interpretation of serological test result for the diagnosis and risk assessment of patient with COVID-19 infection.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Imunoensaio/métodos , Medições Luminescentes/métodos , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Reações Cruzadas/imunologia , Feminino , Humanos , Imunoensaio/normas , Medições Luminescentes/normas , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Reprodutibilidade dos Testes , Soroconversão , Testes Sorológicos , Índice de Gravidade de Doença , Taiwan/epidemiologia
6.
S Afr Med J ; 110(9): 842-845, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32880264

RESUMO

Antibody tests for the novel coronavirus, SARS-CoV2, have been developed both as rapid diagnostic assays and for high-throughput formal serology platforms. Although these tests may be a useful adjunct to a diagnostic strategy, they have a number of limitations. Because of the antibody and viral dynamics of the coronavirus, their sensitivity can be variable, especially at early time points after symptom onset. Additional data are required on the performance of the tests in the South African population, especially with regard to development and persistence of antibody responses and whether antibodies are protective against reinfection. These tests may, however, be useful in guiding the public health response, providing data for research (including seroprevalence surveys and vaccine initiatives) and development of therapeutic strategies.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus , Testes Imunológicos/métodos , Pandemias , Pneumonia Viral , Testes Sorológicos/métodos , Betacoronavirus/genética , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Humanos , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , África do Sul/epidemiologia
7.
Cien Saude Colet ; 25(9): 3573-3578, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32876244

RESUMO

The first case of COVID-19 was reported in China in December 2019, and, as the virus has spread worldwide, the World Health Organization declared it a pandemic. Estimates on the number of COVID-19 cases do not reflect it real magnitude as testing is limited. Population based data on the proportion of the population with antibodies is relevant for planning public health policies. We aim to assess the prevalence of SARS-CoV-2 antibodies, presence of signs and symptoms of COVID-19, and adherence to isolation measures. A random sample comprising 133 sentinel cities from all states of the country will be selected. Three serological surveys, three weeks apart, will be conducted. The most populous municipality in each intermediate region of the country, defined by the Brazilian Institute of Geography and Statistics, was chosen as sentinel city. In each city, 25 census tracts will be selected, and 10 households will be systematically sampled in each tract, totaling 33,250 participants. In each household, one inhabitant will be randomly selected to be interviewed and tested for antibodies against SARS-CoV-2, using WONDFO SARS-CoV-2 Antibody Test. By evaluating a representative sample of Brazilian sentinel sites, this study will provide essential information for the design of health policies.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Saúde Pública , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Brasil/epidemiologia , Infecções por Coronavirus/diagnóstico , Política de Saúde , Humanos , Pandemias , Pneumonia Viral/diagnóstico , Prevalência , Testes Sorológicos
8.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916926

RESUMO

Currently available COVID-19 antibody tests using enzyme immunoassay (EIA) or immunochromatographic assay have variable sensitivity and specificity. Here, we developed and evaluated a novel microsphere-based antibody assay (MBA) for detecting immunoglobulin G (IgG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein (NP) and spike protein receptor binding domain (RBD). The seropositive cutoff value was set using a cohort of 294 anonymous serum specimens collected in 2018. The specificity was assessed using serum specimens collected from organ donors or influenza patients before 2020. Seropositive rate was determined among COVID-19 patients. Time-to-seropositivity and signal-to-cutoff (S/CO) ratio were compared between MBA and EIA. MBA had a specificity of 100% (93/93; 95% confidence interval (CI), 96-100%) for anti-NP IgG, 98.9% (92/93; 95% CI 94.2-100%) for anti-RBD IgG. The MBA seropositive rate for convalescent COVID-19 patients was 89.8% (35/39) for anti-NP IgG and 79.5% (31/39) for anti-RBD IgG. The time-to-seropositivity was shorter with MBA than EIA. MBA could better differentiate between COVID-19 patients and negative controls with higher S/CO ratio for COVID-19 patients, lower S/CO ratio with negative controls and fewer specimens in the equivocal range. MBA is robust, simple and is suitable for clinical microbiology laboratory for the accurate determination of anti-SARS-CoV-2 antibodies for diagnosis, serosurveillance, and vaccine trials.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/sangue , Proteínas do Nucleocapsídeo/imunologia , Pneumonia Viral/sangue , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Infecções por Coronavirus/diagnóstico , Feminino , Humanos , Lactente , Masculino , Microesferas , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Sensibilidade e Especificidade , Testes Sorológicos/normas
9.
PLoS Pathog ; 16(9): e1008817, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970782

RESUMO

There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.


Assuntos
Anticorpos Antivirais/análise , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Testes Sorológicos/métodos , Adulto , Idoso , Betacoronavirus , Técnicas de Laboratório Clínico , Serviços de Saúde Comunitária , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitais , Humanos , Imunoensaio , Medições Luminescentes , Masculino , Pessoa de Meia-Idade , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
10.
PLoS Pathog ; 16(9): e1008796, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32913364

RESUMO

There is an urgent need for effective treatment and preventive vaccine to contain this devastating global pandemic, which requires a comprehensive understanding of humoral responses specific to SARS-CoV-2 during the disease progression and convalescent phase of COVID-19 patients. We continuously monitored the serum IgM and IgG responses specific to four SARS-CoV-2 related antigens, including the nucleoprotein (NP), receptor binding domain (RBD), S1 protein, and ectodomain (ECD) of the spike protein among non-severe and severe COVID-19 patients for seven weeks since disease onset. Most patients generated humoral responses against NP and spike protein-related antigens but with their distinct kinetics profiles. Combined detection of NP and ECD antigens as detecting antigen synergistically improved the sensitivity of the serological assay, compared to that of using NP or RBD as detection antigen. 80.7% of convalescent sera from COVID-19 patients revealed that the varying extents of neutralization activities against SARS-CoV-2. S1-specific and ECD-specific IgA responses were strongly correlated with the neutralization activities in non-severe patients, but not in severe patients. Moreover, the neutralizing activities of the convalescent sera were shown to significantly decline during the period between 21 days to 28 days after hospital discharge, accompanied by a substantial drop in RBD-specific IgA response. Our data provide evidence that are crucial for serological testing, antibody-based intervention, and vaccine design of COVID-19.


Assuntos
Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/patogenicidade , Humanos , Imunoglobulina G/sangue , Estudos Longitudinais , Pandemias , Testes Sorológicos , Glicoproteína da Espícula de Coronavírus/imunologia
11.
BMC Infect Dis ; 20(1): 669, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32928130

RESUMO

BACKGROUND: The parasite Entamoeba histolytica is the causal agent of amoebiasis, a worldwide emerging disease. Amebic brain abscess is a form of invasive amebiasis that is both rare and frequently lethal. This condition always begins with the infection of the colon by E. histolytica trophozoites, which subsequently travel through the bloodstream to extraintestinal tissues. CASE PRESENTATION: We report a case of a 71-year-old female who reported an altered state of consciousness, disorientation, sleepiness and memory loss. She had no history of hepatic or intestinal amoebiasis. A preliminary diagnosis of colloidal vesicular phase neurocysticercosis was made based on nuclear magnetic resonance imaging (NMRI). A postsurgery immunofluorescence study was positive for the 140 kDa fibronectin receptor of E. histolytica, although a serum analysis by ELISA was negative for IgG antibodies against this parasite. A specific E. histolytica 128 bp rRNA gene was identified by PCR in biopsy tissue. The final diagnosis was cerebral amoebiasis. The patient underwent neurosurgery to eliminate amoebic abscesses and was then given a regimen of metronidazole, ceftriaxone and dexamethasone for 4 weeks after the neurosurgery. However, a rapid decline in her condition led to death. CONCLUSIONS: The present case of an individual with a rare form of cerebral amoebiasis highlights the importance of performing immunofluorescence, NMRI and PCR if a patient has brain abscess and a poorly defined diagnosis. Moreover, the administration of corticosteroids to such patients can often lead to a rapid decline in their condition.


Assuntos
Abscesso Encefálico/diagnóstico , Abscesso Encefálico/parasitologia , Infecções Parasitárias do Sistema Nervoso Central/diagnóstico , Entamebíase/diagnóstico , Idoso , Animais , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/cirurgia , Ceftriaxona/administração & dosagem , Infecções Parasitárias do Sistema Nervoso Central/tratamento farmacológico , Infecções Parasitárias do Sistema Nervoso Central/patologia , Infecções Parasitárias do Sistema Nervoso Central/cirurgia , Terapia Combinada , DNA de Protozoário/análise , Dexametasona/administração & dosagem , Quimioterapia Combinada , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Entamebíase/tratamento farmacológico , Entamebíase/patologia , Entamebíase/cirurgia , Evolução Fatal , Feminino , Humanos , Metronidazol/administração & dosagem , Procedimentos Neurocirúrgicos , Testes Sorológicos
12.
Nat Commun ; 11(1): 4698, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943630

RESUMO

Given the limited availability of serological testing to date, the seroprevalence of SARS-CoV-2-specific antibodies in different populations has remained unclear. Here, we report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seroreactivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors in early April 2020. We additionally describe the longitudinal dynamics of immunoglobulin-G (IgG), immunoglobulin-M (IgM), and in vitro neutralizing antibody titers in COVID-19 patients. The median time to seroconversion ranged from 10.3-11.0 days for these 3 assays. Neutralizing antibodies rose in tandem with immunoglobulin titers following symptom onset, and positive percent agreement between detection of IgG and neutralizing titers was >93%. These findings emphasize the importance of using highly accurate tests for surveillance studies in low-prevalence populations, and provide evidence that seroreactivity using SARS-CoV-2 anti-nucleocapsid protein IgG and anti-spike IgM assays are generally predictive of in vitro neutralizing capacity.


Assuntos
Anticorpos Neutralizantes/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Anticorpos Antivirais/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , São Francisco/epidemiologia , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Testes Sorológicos/métodos
13.
Nat Commun ; 11(1): 4378, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873791

RESUMO

Children are strikingly underrepresented in COVID-19 case counts. In the United States, children represent 22% of the population but only 1.7% of confirmed SARS-CoV-2 cases as of April 2, 2020. One possibility is that symptom-based viral testing is less likely to identify infected children, since they often experience milder disease than adults. Here, to better assess the frequency of pediatric SARS-CoV-2 infection, we serologically screen 1,775 residual samples from Seattle Children's Hospital collected from 1,076 children seeking medical care during March and April of 2020. Only one child was seropositive in March, but seven were seropositive in April for a period seroprevalence of ≈1%. Most seropositive children (6/8) were not suspected of having had COVID-19. The sera of seropositive children have neutralizing activity, including one that neutralized at a dilution > 1:18,000. Therefore, an increasing number of children seeking medical care were infected by SARS-CoV-2 during the early Seattle outbreak despite few positive viral tests.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Visitas a Pacientes , Adolescente , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Feminino , Hospitais , Humanos , Lactente , Recém-Nascido , Masculino , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Estudos Prospectivos , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Estados Unidos/epidemiologia
14.
Indian J Med Res ; 152(1 & 2): 88-94, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32893844

RESUMO

Background & objectives: Public health and diagnostic laboratories are facing huge sample loads for COVID-19 diagnosis by real-time reverse transcription-polymerase chain reaction (RT-PCR). High sensitivity of optimized real-time RT-PCR assays makes pooled testing a potentially efficient strategy for resource utilization when positivity rates for particular regions or groups of individuals are low. We report here a comparative analysis of pooled testing for 5- and 10-sample pools by real-time RT-PCR across 10 COVID-19 testing laboratories in India. Methods: Ten virus research and diagnostic laboratories (VRDLs) testing for COVID-19 by real-time RT-PCR participated in this evaluation. At each laboratory, 100 nasopharyngeal swab samples including 10 positive samples were used to create 5- and 10-sample pools with one positive sample in each pool. RNA extraction and real-time RT-PCR for SARS-CoV-2-specific E gene target were performed for individual positive samples as well as pooled samples. Concordance between individual sample testing and testing in the 5- or 10-sample pools was calculated, and the variation across sites and by sample cycle threshold (Ct) values was analyzed. Results: A total of 110 each of 5- and 10-sample pools were evaluated. Concordance between the 5-sample pool and individual sample testing was 100 per cent in the Ct value ≤30 cycles and 95.5 per cent for Ctvalues ≤33 cycles. Overall concordance between the 5-sample pooled and individual sample testing was 88 per cent while that between 10-sample pool and individual sample testing was 66 per cent. Although the concordance rates for both the 5- and 10-sample pooled testing varied across laboratories, yet for samples with Ct values ≤33 cycles, the concordance was ≥90 per cent across all laboratories for the 5-sample pools. Interpretation & conclusions: Results from this multi-site assessment suggest that pooling five samples for SARS-CoV-2 detection by real-time RT-PCR may be an acceptable strategy without much loss of sensitivity even for low viral loads, while with 10-sample pools, there may be considerably higher numbers of false negatives. However, testing laboratories should perform validations with the specific RNA extraction and RT-PCR kits in use at their centres before initiating pooled testing.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Viral/isolamento & purificação , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/virologia , Testes Diagnósticos de Rotina/métodos , Feminino , Humanos , Índia/epidemiologia , Masculino , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/genética , Pneumonia Viral/virologia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testes Sorológicos , Manejo de Espécimes , Carga Viral/genética
15.
Artigo em Inglês | MEDLINE | ID: mdl-32906596

RESUMO

A critical point in the management of the SARS-CoV-2 pandemic is the need to promptly identify the greatest number of infected people and to implement strict public health measures. In this study, the performance of a rapid serological test in a clinical setting was evaluated. Samples from 819 consecutive patients (with or without respiratory symptoms) admitted to a large Emergency Department were tested between 23 March and 21 April 2020. Patient samples were tested in a real-time PCR assay and a serological assay. In total, 148/819 patients (18.1%) tested positive for SARS-CoV-2 by real-time PCR. The serological test revealed that 70/819 patients (8.5%) had anti-SARS-CoV-2 IgM and/or IgG. The prevalence of anti-SARS-CoV-2 antibodies was significantly higher in patients with respiratory symptoms lasting for >7 days than in those with respiratory symptoms lasting for 0-7 days (p < 0.001). The serological assay had an overall sensitivity of 35.1% and an overall specificity of 97.3%. A high negative predictive value (96.7%) was reported for patients without respiratory symptoms. The results confirm that rapid serological assays alone are not sufficient for diagnosis of SARS-CoV-2 infection but can be incorporated into large-scale screening programs during periods in which the virus circulation is low.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Serviço Hospitalar de Emergência/estatística & dados numéricos , Pandemias , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Infecções por Coronavirus/epidemiologia , Humanos , Imunoglobulina G/sangue , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
16.
Viruses ; 12(9)2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32867108

RESUMO

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) compromises the ability of military forces to fulfill missions. At the beginning of May 2020, 22 out of 70 Belgian soldiers deployed to a military education and training center in Maradi, Niger, developed mild COVID-19 compatible symptoms. Immediately upon their return to Belgium, and two weeks later, all seventy soldiers were tested for SARS-CoV-2 RNA (RT-qPCR) and antibodies (two immunoassays). Nine soldiers had at least one positive COVID-19 diagnostic test result. Five of them exhibited COVID-19 symptoms (mainly anosmia, ageusia, and fever), while four were asymptomatic. In four soldiers, SARS-CoV-2 viral load was detected and the genomes were sequenced. Conventional and genomic epidemiological data suggest that these genomes have an African most recent common ancestor and that the Belgian military service men were infected through contact with locals. The medical military command implemented testing of all Belgian soldiers for SARS-CoV-2 viral load and antibodies, two to three days before their departure on a mission abroad or on the high seas, and for specific missions immediately upon their return in Belgium. Some military operational settings (e.g., training camps in austere environments and ships) were also equipped with mobile infectious disease (COVID-19) testing capacity.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Militares/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Adulto , Bélgica/epidemiologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Surtos de Doenças , Humanos , Masculino , Epidemiologia Molecular , Níger/epidemiologia , Pandemias , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Testes Sorológicos , Carga Viral , Adulto Jovem
17.
ESMO Open ; 5(5)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32878898

RESUMO

BACKGROUND: During the COVID-19 outbreak, healthcare professionals (HCP) are at the frontline of clinical management and at increased risk for infection. The SARS-CoV-2 seroprevalence of oncological HCP and their patients has significant implications for oncological care. METHODS: HCP and patients with cancer at the Division of Oncology, Medical University of Vienna were included between 21 March and 4 June and tested for total antibodies against SARS-CoV-2 employing the Roche Elecsys Anti-SARS-CoV-2 immunoassay. Reactive samples were confirmed or disproved by the Abbott SARS-CoV-2 IgG test. Additionally, a structured questionnaire regarding basic demographic parameters, travel history and COVID-19-associated symptoms had to be completed by HCP. RESULTS: 146 subjects (62 HCP and 84 patients with cancer) were enrolled. In the oncological HCP cohort, 20 (32.3%) subjects were medical oncologists, 28 (45.2%) nurses at our ward and 14 (22.6%) fulfil other functions such as study coordinators. In the patient cohort, most individuals are on active anticancer treatment (96.4%). 26% of the HCP and 6% of the patients had symptoms potentially associated with COVID-19 since the end of February 2020. However, only in 2 (3.2%) HCP and in 3 (3.6%) patients, anti-SARS-Cov-2 total antibodies were detected. The second assay for anti-SARS-Cov-2 IgG antibodies confirmed the positive result in all HCP and in 2 (2.4%) patients, suggesting an initial assay's unspecific reaction in one case. In individuals with a confirmed test result, an active COVID-19 infection was documented by a positive SARS-CoV-2 RNA PCR test. CONCLUSION: Specific anti-SARS-CoV-2 antibodies were found solely in persons after a documented SARS-CoV-2 viral infection, thus supporting the test methods' high sensitivity and specificity. The low prevalence of anti-SARS-CoV-2 antibodies in our cohorts indicates a lack of immunity against SARS-CoV-2. It highlights the need for continued strict safety measures to prevent uncontrolled viral spread among oncological HCPs and patients with cancer.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Corpo Clínico Hospitalar , Serviço Hospitalar de Oncologia , Pacientes , Pneumonia Viral/diagnóstico , Testes Sorológicos , Centros de Atenção Terciária , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Betacoronavirus/patogenicidade , Biomarcadores/sangue , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Feminino , Interações Hospedeiro-Patógeno , Humanos , Masculino , Pessoa de Meia-Idade , Recursos Humanos de Enfermagem no Hospital , Oncologistas , Enfermagem Oncológica , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Estudos Soroepidemiológicos , Adulto Jovem
18.
Emerg Microbes Infect ; 9(1): 1955-1957, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32869728

RESUMO

The case refers to a 51-year-old symptomatic man with a new SARS-CoV-2 RNA positive nasopharyngeal swab after two negative ones and the lack of significant development of antibody response measured by different diagnostic serological test. Our case underlines that a discrepancy between clinical course of SARS-CoV-2 infection and results from diagnostic tests may exist. This concept is rapidly emerging and supports the need for a deep knowledge of available and "in development" tests for a correct interpretation of their findings.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Imunoglobulina G/sangue , Pneumonia Viral/diagnóstico , Infecções por Coronavirus/tratamento farmacológico , Ensaio de Imunoadsorção Enzimática , Reações Falso-Negativas , Humanos , Hidroxicloroquina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/tratamento farmacológico , Reação em Cadeia da Polimerase , Quarentena , Recidiva , Testes Sorológicos , Carga Viral
19.
Curr Opin HIV AIDS ; 15(6): 345-350, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32969974

RESUMO

PURPOSE OF REVIEW: To discuss the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by nucleic acid and antibody testing as well as its contribution to mitigating the spread of coronavirus disease 2019. RECENT FINDINGS: Nucleic acid testing (NAT) is the firstly developed and most widely used diagnostic technique for SARS-CoV-2 infection. However, the sensitivity of SARS-CoV-2 RNA NAT assays is always unsatisfactory, mainly due to insufficient viral RNA in samples, especially when upper respiratory samples were used. Compared with NAT assays, serological tests are more convenient and less dependent on the quality of sample collection. But the sensitivity of antibody assays varies largely to test samples collected at different time after onset of symptoms. The diagnostic sensitivity can be significantly improved by combination of RNA and antibody testing. Due to the lack of effective drugs and vaccines, population prevention results mainly from timely triage and quarantine of SARS-CoV-2 infected individuals. Thus, extensive testing with NAT and antibody assays simultaneously is very important to constrain coronavirus disease 2019 epidemic. SUMMARY: Viral RNA testing combining with serological testing could improve the early diagnosis of SARS-CoV-2 infection, which has great value for clinical practice and public health.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/diagnóstico , Pneumonia Viral/prevenção & controle , Técnicas de Laboratório Clínico , Diagnóstico Precoce , Humanos , RNA Viral/análise , Testes Sorológicos
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