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2.
PLoS One ; 16(7): e0255412, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34324603

RESUMO

A second wave of COVID-19 has demonstrated how challenging it will be to achieve sustained control of the disease, even with vaccination underway in many countries. Therefore, it remains relevant to keep improving our understanding of the distribution of COVID-19, especially of asymptomatic individuals, among different populations, and particularly in vulnerable regions. Hence, this population-based serosurvey had the objective of estimating the prevalence of individuals 18 years of age or older infected by SARS-CoV-2, and the proportion of asymptomatic individuals, among a vulnerable population living in an urban setting. This was a cross-sectional single-stage cluster sampling serosurvey conducted between September and December of 2019, in a vulnerable region of the city of São Paulo, Brazil. Families covered by three public primary healthcare units represented the selected clusters. After study inclusion, participants were asked about signs and symptoms related to COVID-19, and had collected 10 mL of blood for serology testing. A total of 272 individuals from 185 families were included in the study, out of the 400 eligible individuals for inclusion, resulting in a non-response rate of 32%. The post stratified prevalence of individuals infected by SARS-CoV-2 was 45.2% (95% CI: 39.4-51.0%), with a proportion of asymptomatic cases of 30.2% (95% CI: 23.3-38.0%). This population-based serosurvey identified a greater prevalence of infected individuals by SARS-CoV-2 compared to data from the beginning of the pandemic, and from a recent citywide serosurvey, with a similar proportion of asymptomatic individuals. It demonstrated the value of primary healthcare services for disease surveillance activities, and the importance of more focused serosurveys, especially in vulnerable locations, and the need to evaluate new surveillance strategies to take into account asymptomatic cases.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/sangue , COVID-19/epidemiologia , Adulto , Idoso , Infecções Assintomáticas/epidemiologia , Brasil/epidemiologia , Cidades/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Prevalência , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Inquéritos e Questionários
3.
Nat Commun ; 12(1): 4383, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34282139

RESUMO

In February and March 2020, two mass swab testing campaigns were conducted in Vo', Italy. In May 2020, we tested 86% of the Vo' population with three immuno-assays detecting antibodies against the spike and nucleocapsid antigens, a neutralisation assay and Polymerase Chain Reaction (PCR). Subjects testing positive to PCR in February/March or a serological assay in May were tested again in November. Here we report on the results of the analysis of the May and November surveys. We estimate a seroprevalence of 3.5% (95% Credible Interval (CrI): 2.8-4.3%) in May. In November, 98.8% (95% Confidence Interval (CI): 93.7-100.0%) of sera which tested positive in May still reacted against at least one antigen; 18.6% (95% CI: 11.0-28.5%) showed an increase of antibody or neutralisation reactivity from May. Analysis of the serostatus of the members of 1,118 households indicates a 26.0% (95% CrI: 17.2-36.9%) Susceptible-Infectious Transmission Probability. Contact tracing had limited impact on epidemic suppression.


Assuntos
Anticorpos Antivirais/imunologia , Teste para COVID-19/métodos , COVID-19/imunologia , COVID-19/transmissão , SARS-CoV-2/imunologia , Testes Sorológicos/métodos , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste de Ácido Nucleico para COVID-19 , Busca de Comunicante , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Itália/epidemiologia , Masculino , Nucleocapsídeo , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia
4.
BMC Infect Dis ; 21(1): 609, 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34171990

RESUMO

BACKGROUND: The prevalence of hepatitis C virus (HCV) among people who inject drugs (PWID) continues to be a major public-health burden in this highly stigmatised population. To halt transmission of HCV, rapid HCV self-testing kits represent an innovative approach that could enable PWID to know their HCV status and seek treatment. As no HCV test has yet been licenced for self-administration, it is crucial to obtain knowledge around the factors that may deter or foster delivery of HCV self-testing among PWID in resource-constrained countries. METHODS: A qualitative study to assess values and preferences relating to HCV self-testing was conducted in mid-2020 among PWID in the Bishkek and Chui regions of Kyrgyzstan. Forty-seven PWID participated in 15 individual interviews, two group interviews (n = 12) and one participatory action-research session (n = 20). Responses were analysed using a thematic analysis approach with 4 predefined themes: awareness of HCV and current HCV testing experiences, and acceptability and service delivery preferences for HCV self-testing. Informants' insights were analysed using a thematic analysis approach. This research received local ethics approval. RESULTS: Awareness of HCV is low and currently PWID prefer community-based HCV testing due to stigma encountered in other healthcare settings. HCV self-testing would be accepted and appreciated by PWID. Acceptability may increase if HCV self-testing: was delivered in pharmacies or by harm reduction associations; was free of charge; was oral rather than blood-based; included instructions with images and clear information on the test's accuracy; and was distributed alongside pre- and post-testing counselling with linkage to confirmatory testing support. CONCLUSIONS: HCV self-testing could increase awareness of and more frequent testing for HCV infection among PWID in Kyrgyzstan. It is recommended that peer-driven associations are involved in the delivery of any HCV self-testing. Furthermore, efforts should be maximised to end discrimination against PWID at the healthcare institutions responsible for confirmatory HCV testing and treatment provision.


Assuntos
Autoavaliação Diagnóstica , Hepatite C/diagnóstico , Preferência do Paciente , Abuso de Substâncias por Via Intravenosa , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Redução do Dano , Hepacivirus/isolamento & purificação , Hepatite C/complicações , Hepatite C/epidemiologia , Hepatite C/psicologia , Humanos , Quirguistão/epidemiologia , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Preferência do Paciente/psicologia , Preferência do Paciente/estatística & dados numéricos , Prevalência , Autoteste , Testes Sorológicos/métodos , Valores Sociais , Abuso de Substâncias por Via Intravenosa/diagnóstico , Abuso de Substâncias por Via Intravenosa/epidemiologia , Abuso de Substâncias por Via Intravenosa/psicologia , Abuso de Substâncias por Via Intravenosa/virologia , Inquéritos e Questionários , Adulto Jovem
5.
Pathology ; 53(5): 645-651, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34119335

RESUMO

During New Zealand's first outbreak in early 2020 the Southern Region had the highest per capita SARS-CoV-2 infection rate. Polymerase chain reaction (PCR) testing was initially limited by a narrow case definition and limited laboratory capacity, and cases may have been missed. Our objectives were to evaluate the Abbott SARS-CoV-2 IgG nucleocapsid assay, alongside spike-based assays, and to determine the frequency of antibodies among PCR-confirmed and probable cases, and higher risk individuals in the Southern Region of New Zealand. Pre-pandemic sera (n=300) were used to establish assay specificity and sera from PCR-confirmed SARS-CoV-2 patients (n=78) to establish sensitivity. For prevalence analysis, all samples (n=1214) were tested on the Abbott assay, and all PCR-confirmed cases (n=78), probable cases (n=9), and higher risk individuals with 'grey-zone' (n=14) or positive results (n=11) were tested on four additional SARS-CoV-2 serological assays. The median time from infection onset to serum collection for PCR-confirmed cases was 14 weeks (range 11-17 weeks). The Abbott assay demonstrated a specificity of 99.7% (95% CI 98.2-99.99%) and a sensitivity of 76.9% (95% CI 66.0-85.7%). Spike-based assays demonstrated superior sensitivity ranging 89.7-94.9%. Nine previously undiagnosed sero-positive individuals were identified, and all had epidemiological risk factors. Spike-based assays demonstrated higher sensitivity than the Abbott IgG assay, likely due to temporal differences in antibody persistence. No unexpected SARS-CoV-2 infections were found in the Southern Region of New Zealand, supporting the elimination status of the country at the time this study was conducted.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/imunologia , SARS-CoV-2/imunologia , Testes Sorológicos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Fosfoproteínas/imunologia , Sensibilidade e Especificidade , Adulto Jovem
6.
Pan Afr Med J ; 39: 3, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178231

RESUMO

While molecular techniques remain the gold standard for diagnosis of acute SARS-CoV-2 infection, serological tests have the unique potential to ascertain how much of the population has been exposed to the COVID-19 pathogen. There have been limited published studies to date documenting the performance of SARS-CoV-2 antibody assays in Nigeria and so we evaluated the diagnostic performance of five (5) immunoassay on a set of clinical samples. Five automated immunoassays (2019-nCoV IgG/IgM antibody determination kit, Tigsun COVID-19 combo IgM/IgG rapid test, rapid response COVID-19 IgG/IgM test, COVID-19 IgM-IgG combined antibody rapid test, iChroma COVID-19 Ab) were tested. Three hundred and fourteen specimens were analyzed from health care workers who tested positive PCR for SARS-CoV-2 with symptoms consistent with SARS-CoV-2 receiving treatment at two treatment centres in Nasarawa State from March to September, 2020 with control of 134 health care workers who tested negative PCR for SARS-CoV-2 with no symptoms to SARS-CoV-2. The median patients' age was 40 years (IQR 39.8-41), majority were male and were on admission. The SARS-CoV-2 IgG/IgM antibody evaluated kits had a sensitivity of 33% (2019-nCoV IgG/IgM antibody determination kit), 22% (Tigsun COVID-19 combo IgM/IgG rapid test), 43% (rapid response COVID-19 IgG/IgM test), 44% (COVID-19 IgM-IgG combined antibody rapid test), 25% (iChroma COVID-19 Ab), 100% sensitivity, accuracy of 68.5% and Kappa coefficient of 0.7 and rapid response COVID-19 IgG/IgM test cassette had a sensitivity of 33%, specificity of 100% and accuracy of 72.5% with Kappa coefficient 0.7. The Tigsun COVID-19 combo IgM/IgG rapid test (lateral flow), positive, COVID-19 IgM-IgG combined antibody rapid test and iChroma COVID-19 Ab RT all had sensitivity of zero percent. Serology was complementary to RT-PCR for the diagnosis of COVID-19 at least 14 days after onset of symptoms. The assay panel needs to be improved to serve as an option for the diagnosis of SARS-CoV-2 in resource constrained settings where there are limited molecular diagnostics testing panels.


Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , Imunoensaio/métodos , SARS-CoV-2/isolamento & purificação , Adulto , Anticorpos Antivirais/sangue , COVID-19/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Nigéria , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Testes Sorológicos/métodos
7.
Viruses ; 13(4)2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807442

RESUMO

Flaviviruses circulate worldwide and cause a number of medically relevant human diseases, such as dengue, Zika, yellow fever, and tick-borne encephalitis (TBE). Serology plays an important role in the diagnosis of flavivirus infections, but can be impeded by antigenic cross-reactivities among flaviviruses. Therefore, serological diagnosis of a recent infection can be insufficiently specific, especially in areas where flaviviruses co-circulate and/or vaccination coverage against certain flaviviruses is high. In this study, we developed a new IgM assay format, which is well suited for the specific diagnosis of TBE, Zika and dengue virus infections. In the case of TBE and Zika, the IgM response proved to be highly specific for the infecting virus. In contrast, primary dengue virus infections induced substantial amounts of cross-reactive IgM antibodies, which is most likely explained by structural peculiarities of dengue virus particles. Despite the presence of cross-reactive IgM, the standardized nature and the quantitative read-out of the assay even allowed the serotype-specific diagnosis of recent dengue virus infections in most instances.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Reações Cruzadas/imunologia , Infecções por Flavivirus/diagnóstico , Flavivirus/imunologia , Imunoglobulina M/sangue , Testes Sorológicos/métodos , Antígenos Virais/classificação , Estudos de Coortes , Dengue/sangue , Dengue/diagnóstico , Dengue/imunologia , Vírus da Dengue/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/imunologia , Flavivirus/classificação , Infecções por Flavivirus/sangue , Infecções por Flavivirus/virologia , Humanos , Sorogrupo , Testes Sorológicos/normas , Zika virus/imunologia , Infecção por Zika virus/sangue , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/imunologia
8.
J Hepatol ; 75(2): 435-438, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33892006

RESUMO

BACKGROUND & AIMS: Two SARS-CoV-2 mRNA vaccines were approved to prevent COVID-19 infection, with reported vaccine efficacy of 95%. Liver transplant (LT) recipients are at risk of lower vaccine immunogenicity and were not included in the registration trials. We assessed vaccine immunogenicity and safety in this special population. METHODS: LT recipients followed at the Tel-Aviv Sourasky Medical Center and healthy volunteers were tested for SARS-CoV-2 IgG antibodies directed against the Spike-protein (S) and Nucleocapsid-protein (N) 10-20 days after receiving the second Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine dose. Information regarding vaccine side effects and clinical data was collected from patients and medical records. RESULTS: Eighty LT recipients were enrolled. Mean age was 60 years and 30% were female. Twenty-five healthy volunteer controls were younger (mean age 52.7 years, p = 0.013) and mostly female (68%, p = 0.002). All participants were negative for IgG N-protein serology, indicating immunity did not result from prior COVID-19 infection. All controls were positive for IgG S-protein serology. Immunogenicity among LT recipients was significantly lower with positive serology in only 47.5% (p <0.001). Antibody titer was also significantly lower in this group (mean 95.41 AU/ml vs. 200.5 AU/ml in controls, p <0.001). Predictors for negative response among LT recipients were older age, lower estimated glomerular filtration rate, and treatment with high dose steroids and mycophenolate mofetil. No serious adverse events were reported in either group. CONCLUSION: LT recipients developed substantially lower immunological response to the Pfizer-BioNTech SARS-CoV-2 mRNA-based vaccine. Factors influencing serological antibody responses include age, renal function and immunosuppressive medications. The findings require re-evaluation of vaccine regimens in this population. LAY SUMMARY: The Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine elicited substantially inferior immunity in liver transplant recipients. Less than half of the patients developed sufficient levels of antibodies against the virus, and in those who were positive, average antibody levels were 2x less compared to healthy controls. Factors predicting non-response were older age, renal function and immunosuppressive medications.


Assuntos
Anticorpos Antivirais/sangue , Vacinas contra COVID-19 , COVID-19 , Imunogenicidade da Vacina/imunologia , Imunoglobulina G/sangue , Imunossupressores/uso terapêutico , Transplante de Fígado/métodos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/imunologia , Feminino , Humanos , Imunossupressão/métodos , Israel/epidemiologia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Fatores de Risco , SARS-CoV-2/imunologia , Testes Sorológicos/métodos , Testes Sorológicos/estatística & dados numéricos , Vacinação/efeitos adversos , Vacinação/métodos
9.
Lancet Infect Dis ; 21(8): 1141-1150, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33836157

RESUMO

BACKGROUND: Assessment of therapeutic response with standard serological diagnostic assays in patients with chronic Chagas disease is a major challenge due to the long persistence of parasite-specific antibodies. The current consensus for parasitological cure is to monitor conversion from positive to negative Trypanosoma cruzi serology (seroreversion). However, because of robust humoral immune response, seroreversion by standard serological tests can take years to decades. Developing novel tests of parasitological cure or surrogates is thus a priority in the Chagas disease field. We aimed to evaluate the MultiCruzi assay as a predictive tool for parasitological cure in a cohort of treated infants and children with acute and chronic Chagas disease enrolled in a long-term retrospective longitudinal study with clinical, serological, and parasitological follow-up, and to explore whether MultiCruzi could predict parasitological cure more quickly than the current reference method. METHODS: Patients from two retrospective paediatric Chagas disease cohort studies with clinical, serological, and parasitological follow-up, diagnosed and treated at the parasitology service, Hospital de Niños Ricardo Gutierrez (Buenos Aires, Argentina) were included in this retrospective cohort study. Serum samples were collected every 6 months to 12 months between Oct 22, 1990, and June 3, 2019, for cohort 1 and 1 month after birth for cohort 2 and then every 3 months for a year between July 23, 2012, and April 19, 2016. We evaluated serological follow-up with the Chagatest ELISA (Wiener Lab, Rosario, Argentina) and used this as a clinical reference method for the evaluation of seroreversion. We compared Chagatest ELISA results with results of MultiCruzi (InfYnity Biomarkers, Lyon, France), a novel antibody profiling multiplex assay, investigating seroreversion events with both of the assays and prediction of seroreversion with MultiCruzi using an interpretation formula. FINDINGS: Combining experimental data from discrete analysis of 15 T cruzi antigens efficiently predicted seroreversion at an early stage, which was later confirmed by conventional T cruzi serology. In cohort 1 (n=69), which included children of three different age groups, we observed differences 2 years after therapy. In the 27 individuals from cohort 1 who were treated within the first 12 months of age, MultiCruzi predicted early seroreversion in 21 (78%) patients whereas nine (33%) patients showed seroreversion with Chagatest ELISA (seroreversion difference 0·44, 95% CI 0·26-0·63; p=0·0005). In the 12 patients from cohort 1 treated between 1 year and 2 years of age, MultiCruzi predicted early seroreversion in six (50%) patients, whereas only one (8%) patient was confirmed to be seronegative with Chagatest ELISA (seroreversion difference 0·42, 95% CI 0·14-0·70; p=0·0253). In the 30 patients from cohort 1 who were treated between 2 years and 19 years of age, MultiCruzi predicted early seroreversion in five (6%) patients, whereas no patients were found to be seronegative with Chagatest ELISA (seroreversion difference 0·17, 0·03-0·30; p=0·0253). In cohort 2 (n=27), which included only children younger than 1 year of age and had a shorter follow up (between 5 months and 32 months), the proportion of reported events was significantly different 180 days after treatment for the T cruzi-positive group (early seroreversion predicted in nine [90%] of ten patients with MultiCruzi and confirmed seroreversion in four [40%] of ten patients with Chagatest ELISA; seroreversion difference 0·50, 95% CI 0·19-0·81; p=0·0253) and for the T cruzi-negative group 90 days (early seroreversion predicted in five [29%] of 17 patients with MultiCruzi and confirmed seroreversion in one [6%] of 17 patients with Chagatest ELISA; seroreversion difference 0·24, 0·03-0·44; p=0·0455) and 180 days (early seroreversion predicted in 17 [100%] of 17 patients with MultiCruzi and confirmed seroreversion only in seven [41%] of 17 patients with Chagatest ELISA; seroreversion difference 0·59, 0·35-0·82; p=0·0016) after treatment. INTERPRETATION: The MultiCruzi assay can be used as a predictive monitoring tool to assess parasitological cure in children. This approach might be a solution to forecast forthcoming seroreversion in treated adults infected with T cruzi, but this requires further investigation. FUNDING: Drugs for Neglected Diseases initiative. TRANSLATIONS: For the Spanish, Portuguese and French translations of the abstract see Supplementary Materials section.


Assuntos
Anticorpos Antiprotozoários/sangue , Antiprotozoários/uso terapêutico , Doença de Chagas/tratamento farmacológico , Testes Sorológicos/métodos , Trypanosoma cruzi/imunologia , Adolescente , Formação de Anticorpos , Argentina , Criança , Pré-Escolar , Monitoramento de Medicamentos , Feminino , França , Humanos , Lactente , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Estudos Retrospectivos , Trypanosoma cruzi/genética , Trypanosoma cruzi/isolamento & purificação , Adulto Jovem
10.
Med Princ Pract ; 30(4): 385-394, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33887722

RESUMO

OBJECTIVE: To assess the diagnostic performance of lateral flow immunochromatographic assays (LFAs) of 4 different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG, or total), comparing them with the nucleic acid amplification test (NAAT) or the clinical defined test (definite or probable SARS-CoV-2 infection, respectively). METHODS: One hundred nineteen serum samples were randomly selected by convenience and distributed in the following groups: (1) group with SARS-CoV-2 infection (n = 82; RT-qPCR positive [definite, n = 70] and probable [n = 12]); (2) other diseases (n = 27; other viruses identified [n = 8] and SARS of other etiologies [n = 19]); and (3) healthy control group (n = 10). LFAs of 4 manufacturers were compared: MedTest Coronavirus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and 1-Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co., China). RESULTS: The 4 tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95% CI: 77.26-93.11%), specificity (100%; 90.51-100%), DOR (257; 60-1,008), LR+ (33.43; 4.82-231.85), LR- (0.13; 0.08-0.23), accuracy (90.76%; 84.06-95.29%), and Matthews correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values. CONCLUSION: Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the different kits. LFA tests cannot replace molecular diagnostics but should be used as an additional screening tool.


Assuntos
Anticorpos Antivirais/sangue , Teste para COVID-19/métodos , Testes Sorológicos/métodos , Brasil/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Técnicas de Amplificação de Ácido Nucleico , Pandemias , SARS-CoV-2 , Sensibilidade e Especificidade
11.
PLoS Negl Trop Dis ; 15(4): e0009336, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33872309

RESUMO

BACKGROUND: Serological diagnosis of Zika virus (ZIKV) infection is challenging because of the antibody cross-reactivity among flaviviruses. At the same time, the role of Nucleic Acid Testing (NAT) is limited by the low proportion of symptomatic infections and the low average viral load. Here, we compared the diagnostic performance of commercially available IgM, IgAM, and IgG ELISAs in sequential samples during the ZIKV and chikungunya (CHIKV) epidemics and co-circulation of dengue virus (DENV) in Brazil and Venezuela. METHODOLOGY/PRINCIPAL FINDINGS: Acute (day of illness 1-5) and follow-up (day of illness ≥ 6) blood samples were collected from nine hundred and seven symptomatic patients enrolled in a prospective multicenter study between June 2012 and August 2016. Acute samples were tested by RT-PCR for ZIKV, DENV, and CHIKV. Acute and follow-up samples were tested for IgM, IgAM, and IgG antibodies to ZIKV using commercially available ELISAs. Among follow-up samples with a RT-PCR confirmed ZIKV infection, anti-ZIKV IgAM sensitivity was 93.5% (43/46), while IgM and IgG exhibited sensitivities of 30.3% (10/33) and 72% (18/25), respectively. An additional 24% (26/109) of ZIKV infections were detected via IgAM seroconversion in ZIKV/DENV/CHIKV RT-PCR negative patients. The specificity of anti-ZIKV IgM was estimated at 93% and that of IgAM at 85%. CONCLUSIONS/SIGNIFICANCE: Our findings exemplify the challenges of the assessment of test performance for ZIKV serological tests in the real-world setting, during co-circulation of DENV, ZIKV, and CHIKV. However, we can also demonstrate that the IgAM immunoassay exhibits superior sensitivity to detect ZIKV RT-PCR confirmed infections compared to IgG and IgM immunoassays. The IgAM assay also proves to be promising for detection of anti-ZIKV seroconversions in sequential samples, both in ZIKV PCR-positive as well as PCR-negative patients, making this a candidate assay for serological monitoring of pregnant women in future ZIKV outbreaks.


Assuntos
Febre de Chikungunya/diagnóstico , Dengue/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Testes Sorológicos/métodos , Infecção por Zika virus/diagnóstico , Adolescente , Adulto , Anticorpos Antivirais/sangue , Sangue/virologia , Brasil , Criança , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Estudos Prospectivos , RNA Viral/sangue , Reação em Cadeia da Polimerase em Tempo Real , Venezuela , Adulto Jovem
12.
PLoS Negl Trop Dis ; 15(4): e0009370, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33909640

RESUMO

BACKGROUND: The diagnosis of cystic echinococcosis (CE) is primarily based on imaging, while serology should be applied when imaging is inconclusive. CE cyst stage has been reported among the most important factors influencing the outcome of serodiagnosis. We performed a systematic review and meta-analysis of the relation between cyst stage of hepatic CE and diagnostic sensitivity of serological tests, to evaluate whether their relation is a consistent finding and provide guidance for the interpretation of results of serological tests. METHODOLOGY/PRINCIPAL FINDINGS: MEDLINE, EMBASE, CENTRAL, and Lilacs databases were searched on December 1st 2019. Original studies published after 2003 (year of publication of the CE cyst classification), reporting sensitivity of serological tests applied to the diagnosis of human hepatic CE, as diagnosed and staged by imaging, were included. The quality of studies was assessed using the Newcastle-Ottawa Scale. Data from 14 studies were included in the meta-analysis. Summary estimates of sensitivities and 95% confidence intervals were obtained using random effects meta-analysis. Overall, test sensitivity was highest in the presence of CE2 and CE3 (CE3a and/or CE3b), and lowest in the presence of CE5 and CE4 cysts. ELISA, ICT and WB showed the highest sensitivities, while IHA performed worst. CONCLUSIONS/SIGNIFICANCE: The results of our study confirm the presence of a clear and consistent relation between cyst stage and serological tests results. Limitations of evidence included the heterogeneity of the antigenic preparations used, which prevented to determine whether the relation between cyst stage and sensitivity was influenced by the type of antigenic preparation, the paucity of studies testing the same panel of sera with different assays, and the lack of studies assessing the performance of the same assay in both field and hospital-based settings. Our results indicate the absolute need to consider cyst staging when evaluating serological results of patients with hepatic CE.


Assuntos
Cistos/patologia , Equinococose Hepática/diagnóstico , Echinococcus/imunologia , Testes Sorológicos/métodos , Animais , Anticorpos Anti-Helmínticos/sangue , Equinococose Hepática/sangue , Equinococose Hepática/parasitologia , Echinococcus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Humanos , Sensibilidade e Especificidade , Fatores de Tempo
13.
Pan Afr Med J ; 38: 55, 2021.
Artigo em Francês | MEDLINE | ID: mdl-33854684

RESUMO

The first outbreak of epidemic respiratory disease due to unknown etiology was reported in the Chinese city of Wuhan December 2019. The World Health Organization (WHO) firstly used the term "new coronavirus 2019" on December 29, 2019. This pandemic, which is currently called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a disease caused by SARS-CoV-2. It was subsequently called coronavirus disease 2019 (COVID-19) by the WHO. The purpose of this study was to determine the prevalence of antibodies against SARS-CoV-2 in all employees of the Nouakchott National Hospital Center (CHN). The study was conducted during the week 20/05/2020 to 27/05/2020. It involved 853 employees of all ranks (doctors, pharmacists, nurses, secretaries, security personnel, administrators...) of whom 504 were male and 331 were female, with a sex ratio of 1,52 with an average age of 39 years, ranging from 20 to 60 years. The screening for IgG and IgM antibodies to SARS-CoV-2 was performed using Biotime (Xiamen Biotime Biotechnology Co., Ltd.) immunochromatographic technique. Out of 835 employees included in our study, 14 were positive (1.67%) of whom 12 had IgM and IgG anti-SARS-CoV-2 antibodies and 2 had isolated IgM. Nasopharyngeal swab polymerase chain reaction (PCR) was performed in these 14 patients and was positive in six. While PCR is the gold standard for the diagnosis of SARS-CoV-2, serological tests for SARS-CoV-2 antibodies, in particular rapid tests (RDTs) are a diagnostic complement to COVID-19. They have the advantage of being easy to realize, of being safe both in the laboratories and outside the laboratories. RDTs enabled us to detect asymptomatic SARS-CoV-2 carriers within CHN employees. This allowed for patients management and isolation to protect patients and their environments.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , Pessoal de Saúde , SARS-CoV-2/isolamento & purificação , Adulto , Anticorpos Antivirais/sangue , COVID-19/epidemiologia , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Masculino , Mauritânia/epidemiologia , Pessoa de Meia-Idade , Testes Sorológicos/métodos , Adulto Jovem
14.
Medicine (Baltimore) ; 100(17): e25695, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33907147

RESUMO

RATIONALE: The chikungunya virus (CHIKV) was first isolated in a Tanzanian epidemic area between 1952 and 1953. The best description of the CHIKV transmission during pregnancy can be found in a well-documented epidemic in 2005, in the "La Reunion" island, a French territory located in the Indian Ocean, in which about one-third of the population was infected. Reports of arbovirus infections in pregnancy are increasing over time, but the spectrum of clinical findings remains an incognita among researchers, including CHIKV. PATIENT CONCERNS: In this report, it was possible to verify 2 cases exposed to CHIKV during foetal period and the possible implications of the infection on gestational structures and exposed children after the birth. DIAGNOSIS: In both cases, the mothers were positive by laboratory tests in serologic analysis for CHIKV, as ezyme-linked immunossorbent assay (ELISA), plaque reduction neutralisation testing (PRNT) and immunofluorescence (IF); but there were no positive tests in quantitative polymerase chain reaction (qPCR) for mothers or children. INTERVENTIONS: The exposed children were followed up in a paediatrics clinic in order not only to provide the medical assistance, but also to verify child development and the possible implications and neurocognitive changes caused by gestational infection. OUTCOMES: There were neurological and developmental changes in one of the children followed up on an outpatient basis. There was an improvement in the neurological situation and symptoms only 3 years and 1 month after birth. LESSONS: Based on the cases presented, we can conclude that clinical symptoms of CHIKV maternal infection may occur late in new-borns and can affect their development.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Complicações Infecciosas na Gravidez , Efeitos Tardios da Exposição Pré-Natal , Transtornos Psicomotores , Tempo , Anticorpos Antivirais/sangue , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/imunologia , Febre de Chikungunya/transmissão , Vírus Chikungunya/imunologia , Vírus Chikungunya/isolamento & purificação , Desenvolvimento Infantil , Pré-Escolar , Continuidade da Assistência ao Paciente , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Testes de Estado Mental e Demência , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/imunologia , Efeitos Tardios da Exposição Pré-Natal/diagnóstico , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Transtornos Psicomotores/diagnóstico , Transtornos Psicomotores/etiologia , Testes Sorológicos/métodos
15.
Viruses ; 13(4)2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33921164

RESUMO

Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30-40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with "false negative" AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81-97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of "false negatives" of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.


Assuntos
Antígenos Virais/análise , Teste para COVID-19/métodos , COVID-19/imunologia , Viabilidade Microbiana , SARS-CoV-2/imunologia , Testes Sorológicos/métodos , Adulto , COVID-19/diagnóstico , Teste de Ácido Nucleico para COVID-19 , Reações Falso-Negativas , Feminino , Humanos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Sensibilidade e Especificidade
16.
PLoS One ; 16(4): e0249938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909632

RESUMO

This study compared the performance of four serology assays for Coronavirus Disease 2019 (COVID-19) and investigated whether COVID-19 disease history correlates with assay performance. Samples were tested at Northshore using the Elecsys Anti-SARS-CoV-2 (Roche Diagnostics), Access SARS-CoV-2 IgG anti-RBD (Beckman Coulter), and LIAISON SARS-CoV-2 S1/S2 IgG (DiaSorin) as well as at Genalyte using Maverick Multi-Antigen Serology Panel. The study included one hundred clinical samples collected before December 2019 and ninety-seven samples collected from convalescent plasma donors originally diagnosed with COVID-19 by PCR. COVID-19 disease history was self-reported by the plasma donors. There was no difference in specificity between the assays tested. Clinical sensitivity of these four tests was 98% (Genalyte), 96% (Roche), 92% (DiaSorin), and 87% (Beckman). The only statistically significant differences in clinical sensitivity was between the Beckman assay and both Genalyte and Roche assays. Convalescent plasma donor characteristics and disease symptoms did not correlate with false negative results from the Beckman and DiaSorin assays. All four tests showed high specificity (100%) and varying sensitivities (89-98%). No correlations between disease history and serology results were observed. The Genalyte Multiplex assay showed as good or better sensitivity to three other previously validated assays with FDA Emergency Use Authorizations.


Assuntos
COVID-19/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Adulto , Idoso , Anticorpos Antivirais/imunologia , Feminino , Humanos , Imunização Passiva/métodos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Plasma/química , Plasma/imunologia , SARS-CoV-2/patogenicidade , Sensibilidade e Especificidade , Testes Sorológicos/métodos
17.
PLoS One ; 16(4): e0250319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909646

RESUMO

Projections of the stage of the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) pandemic and local, regional and national public health policies to limit coronavirus spread as well as "reopen" cities and states, are best informed by serum neutralizing antibody titers measured by reproducible, high throughput, and statically credible antibody (Ab) assays. To date, a myriad of Ab tests, both available and FDA authorized for emergency, has led to confusion rather than insight per se. The present study reports the results of a rapid, point-in-time 1,000-person cohort study using serial blood donors in the New York City metropolitan area (NYC) using multiple serological tests, including enzyme-linked immunosorbent assays (ELISAs) and high throughput serological assays (HTSAs). These were then tested and associated with assays for neutralizing Ab (NAb). Of the 1,000 NYC blood donor samples in late June and early July 2020, 12.1% and 10.9% were seropositive using the Ortho Total Ig and the Abbott IgG HTSA assays, respectively. These serological assays correlated with neutralization activity specific to SARS-CoV-2. The data reported herein suggest that seroconversion in this population occurred in approximately 1 in 8 blood donors from the beginning of the pandemic in NYC (considered March 1, 2020). These findings deviate with an earlier seroprevalence study in NYC showing 13.7% positivity. Collectively however, these data demonstrate that a low number of individuals have serologic evidence of infection during this "first wave" and suggest that the notion of "herd immunity" at rates of ~60% or higher are not near. Furthermore, the data presented herein show that the nature of the Ab-based immunity is not invariably associated with the development of NAb. While the blood donor population may not mimic precisely the NYC population as a whole, rapid assessment of seroprevalence in this cohort and serial reassessment could aid public health decision making.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/imunologia , Doadores de Sangue , COVID-19/imunologia , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , SARS-CoV-2/patogenicidade , Sensibilidade e Especificidade , Soroconversão/fisiologia , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia
18.
Euro Surveill ; 26(13)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33797390

RESUMO

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.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Coronavirus Humano OC43 , SARS-CoV-2/imunologia , Síndrome de Resposta Inflamatória Sistêmica , Adolescente , Anticorpos Antivirais/sangue , COVID-19/sangue , COVID-19/diagnóstico , Criança , Pré-Escolar , Estudos Transversais , Feminino , França/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Paris , Estações do Ano , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus
20.
Korean J Parasitol ; 59(1): 9-14, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33684982

RESUMO

Toxoplasma gondii seroprevalence have been rapidly increasing in some parts of Korea. We analyzed prevalence of anti-Toxoplasma gondii antibodies, using a rapid diagnostic test (RDT), in the sera of 552 residents in Ganghwa-gun, 661 ones in Cheorwon-gun, and 305 ones in Goseong-gun, Korea in 2019. IgG/IgM RDT mounted with recombinant fragment of major surface antigen (SAG1), glutathione-S-transferase-linker-SAG1A, were applied to the sera. IgG seroprevalence was 28.1% in Ganghwa-gun, 19.5% in Cheorwon-gun and 35.7% in Goseong-gun. Odds ratios comparing Cheorwon vs Ganghwa was 0.63 (P=0.001) and Goesong versus Ganghwa was 1.47 (P=0.01) adjusting age and sex. Goseong had highest seroprevalence among the 3 counties both in crude rates and logistic regression. Although Cheorwon and Goseong are adjacent to the demilitarized zone (DMZ) in Korea, seroprevalence rate was much higher in Goseong. Further investigation on other DMZ-closed areas is necessary whether they have high prevalence rates compared to the other areas. T. gondii prevalence in Korea is still persists; proper health policy should be established.


Assuntos
Testes Sorológicos/métodos , Toxoplasma , Toxoplasmose/diagnóstico , Toxoplasmose/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários , Biomarcadores/sangue , Feminino , Humanos , Imunoglobulina G , Imunoglobulina M , Masculino , Pessoa de Meia-Idade , Prevalência , Proteínas de Protozoários , República da Coreia/epidemiologia , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose/parasitologia
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