Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
1.
J Clin Microbiol ; : JCM0171721, 2021 Oct 20.
Article in English | MEDLINE | ID: covidwho-1639280

ABSTRACT

Background: We aimed to assess the specificity of SARS-CoV-2 antibody detection assays among people with tissue-borne parasitic infections. Methods: We tested three SARS-CoV-2 antibody-detection assays [cPass SARS-CoV-2 Neutralization Antibody Detection Kit (cPass), Abbott SARS-CoV-2 IgG assay (Abbott Architect), and STANDARD Q COVID-19 IgM/IgG Combo Rapid Test ("SD RDT IgM"/"SD RDT IgG")] among 559 pre-COVID-19 seropositive sera for several parasitic infections. Results: The specificity of assays was 95-98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95%CI 75-95]), visceral leishmaniasis (SD RDT IgG; 80% [95%CI 30-99]), and from patients with recent malaria from a holoendemic area of Senegal (ranging from 91% for Abbott Architect and SD RDT IgM to 98-99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥ 96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98-100%. The majority (>85%) of false-positive results were positive by only one assay. Conclusions: The specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.

2.
Med Princ Pract ; 2021 Dec 09.
Article in English | MEDLINE | ID: covidwho-1562353

ABSTRACT

OBJECTIVES: We aimed to describe the clinical characteristics of SARS-CoV-2 infection and estimate viral shedding duration in respiratory specimens. METHODS: A retrospective cohort study was performed from Feb 25th to March 25th, 2020. In Kuwait, all suspected coronavirus disease 2019 (COVID-19) cases, contacts of cases, and returning travelers were systematically tested for SARS-CoV-2 by RT-PCR. All infected persons, regardless of symptoms, were hospitalized and serially tested until they had two negative results. Descriptive statistics and regression analyses were performed. RESULTS: 207 cases of SARS-CoV-2 infection were identified. About half of cases were asymptomatic and 1.9% died. The median time to negative RT-PCR was 22 days. Increasing age, ARDS, and low peripheral white blood cell count were associated with prolonged PCR positivity. CONCLUSION: Predictors for prolonged RT-PCR positivity included increasing age, ARDS, and low white blood cell count. The findings of this study may aid in better understanding SARS-CoV-2 infection epidemiology and molecular testing dynamics.

3.
Ann Intern Med ; 174(2): 287-288, 2021 02.
Article in English | MEDLINE | ID: covidwho-1526981
4.
J Clin Microbiol ; : JCM0171721, 2021 Oct 20.
Article in English | MEDLINE | ID: covidwho-1476385

ABSTRACT

Background: We aimed to assess the specificity of SARS-CoV-2 antibody detection assays among people with tissue-borne parasitic infections. Methods: We tested three SARS-CoV-2 antibody-detection assays [cPass SARS-CoV-2 Neutralization Antibody Detection Kit (cPass), Abbott SARS-CoV-2 IgG assay (Abbott Architect), and STANDARD Q COVID-19 IgM/IgG Combo Rapid Test ("SD RDT IgM"/"SD RDT IgG")] among 559 pre-COVID-19 seropositive sera for several parasitic infections. Results: The specificity of assays was 95-98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95%CI 75-95]), visceral leishmaniasis (SD RDT IgG; 80% [95%CI 30-99]), and from patients with recent malaria from a holoendemic area of Senegal (ranging from 91% for Abbott Architect and SD RDT IgM to 98-99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥ 96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98-100%. The majority (>85%) of false-positive results were positive by only one assay. Conclusions: The specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.

5.
Open Forum Infect Dis ; 8(6): ofab220, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1276208

ABSTRACT

Background: Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) surrogate neutralization assays that obviate the need for viral culture offer substantial advantages regarding throughput and cost. The cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript) is the first such commercially available assay that detects antibodies that block receptor-binding domain (RBD)/angiotensin-converting enzyme (ACE)-2 interaction. We aimed to evaluate cPass to inform its use and assess its added value compared with anti-RBD enzyme-linked immunosorbent assays (ELISAs). Methods: Serum reference panels comprising 205 specimens were used to compare cPass to plaque-reduction neutralization test (PRNT) and a pseudotyped lentiviral neutralization (PLV) assay for detection of neutralizing antibodies. We assessed the correlation of cPass with an ELISA detecting anti-RBD immunoglobulin (Ig)G, IgM, and IgA antibodies at a single timepoint and across intervals from onset of symptoms of SARS-CoV-2 infection. Results: Compared with PRNT-50, cPass sensitivity ranged from 77% to 100% and specificity was 95% to 100%. Sensitivity was also high compared with the pseudotyped lentiviral neutralization assay (93%; 95% confidence interval [CI], 85-97), but specificity was lower (58%; 95% CI, 48-67). Highest agreement between cPass and ELISA was for anti-RBD IgG (r = 0.823). Against the pseudotyped lentiviral neutralization assay, anti-RBD IgG sensitivity (99%; 95% CI, 94-100) was very similar to that of cPass, but overall specificity was lower (37%; 95% CI, 28-47). Against PRNT-50, results of cPass and anti-RBD IgG were nearly identical. Conclusions: The added value of cPass compared with an IgG anti-RBD ELISA was modest.

6.
Ann Intern Med ; 173(6): 450-460, 2020 09 15.
Article in English | MEDLINE | ID: covidwho-937708

ABSTRACT

Accurate serologic tests to detect host antibodies to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) will be critical for the public health response to the coronavirus disease 2019 pandemic. Many use cases are envisaged, including complementing molecular methods for diagnosis of active disease and estimating immunity for individuals. At the population level, carefully designed seroepidemiologic studies will aid in the characterization of transmission dynamics and refinement of disease burden estimates and will provide insight into the kinetics of humoral immunity. Yet, despite an explosion in the number and availability of serologic assays to test for antibodies against SARS-CoV-2, most have undergone minimal external validation to date. This hinders assay selection and implementation, as well as interpretation of study results. In addition, critical knowledge gaps remain regarding serologic correlates of protection from infection or disease, and the degree to which these assays cross-react with antibodies against related coronaviruses. This article discusses key use cases for SARS-CoV-2 antibody detection tests and their application to serologic studies, reviews currently available assays, highlights key areas of ongoing research, and proposes potential strategies for test implementation.


Subject(s)
Betacoronavirus/immunology , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Serologic Tests/methods , COVID-19 , COVID-19 Testing , Humans , Pandemics , SARS-CoV-2 , Seroepidemiologic Studies
SELECTION OF CITATIONS
SEARCH DETAIL
...