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Objective: Aim of this observational is to evaluate the sensitivity and specificity a rapid diagnostic test for COVID-19 for screening COVID-19 pediatric patients. Study Design: 179 Patients under 18 years old with a history of COVID-19 symptoms, and who underwent PCR and/or reference antibody testing for COVID-19. Results: The sampel of this study consisted of 179 patient who 100 sunject with reactive in rapid antibody diagnostic test COVID 19 which consisting of 40 subject positive SARS-CoV2 PCR swab examination and 60 subject negative SARS-CoV2 PCR swab examination. The patient with nonreactive result in rapid antibody diagnostic test COVID 19 which consisting of 19 subject positive SARS-CoV2 PCR swab examination and 60 subject negative SARS-CoV2 PCR swab examination. The sensitivity of the test was 67%. Specificity was 50%. There was substantial agreement between SARS-CoV2 PCR results and a rapid antibody diagnostic test COVID 19. Conclusion: The current evaluation of antibody-based system shows low sensitivity and low specificity result. © 2022 Universidad Tecnica de Manabi. All rights reserved.
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Introduction: COVID-19 has been declared as Public Health Emergency of International Concern with extreme risk of sustained global spread. The pandemic is likely to evolve in successive waves until herd immunity threshold (HIT) is achieved. Asymptomatic carriers and contacts are likely to elude case reporting through conventional algorithm of case finding, testing, contact tracing, and outbreak surveillance, thereby leading to underestimation of disease burden. Widespread community-level transmission of COVID-19 renders higher risk to health-care personnel due to higher propensity and duration of multiple exposures compared to general population. Methods: This is a cross-sectional clinicoepidemiological outcome surveillance study on prevaccination seroprevalence of COVID-19 immunoglobulin G (IgG) antibodies against S1 receptor binding domain in health-care personnel and general population. Results: Seroprevalence of COVID-19 IgG in 570 health-care personnel was 224/570 (39.3%), without any skew based on age or gender. 75% were exposed in the hospital while 21.2% were exposed during travel and 3.1% through high-risk contact outside the hospital. Out of 33 COVID-19 positives, 88% underwent hospital isolation including one ICU admission and 12 home isolation. Seroprevalence of COVID-19 IgG in 400 individuals from general population samples was 138/400 (34.5%). Conclusion: Prevaccination seroprevalence of COVID-19 IgG antibodies after the first pandemic wave revealed no significant difference among health-care personnel and general population reflecting upon a possibility of consecutive pandemic waves until community attainment of HIT. Seroepidemiology can be a robust tool essential to ascertain exposure, immune response, immunity status, and predict susceptibility in population cohorts.
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OBJECTIVES: To assess the seroprevalence of SARS-CoV-2 antibodies in municipal employees of Northern Portugal during the first pandemic wave (May-June 2020) and its association with potentially related risk factors for infection. MATERIAL AND METHODS: The authors assessed municipal employees of 2 cities in Northern Portugal, in whom serological tests to SARS-CoV-2 and an epidemiological survey were applied. The authors assessed the proportion of individuals presenting IgM and/or IgG antibodies to SARS-CoV-2, and evaluated the association between having positive serological test results, epidemiologic variables and clinical presentations. Reported symptoms were evaluated on their sensitivity, specificity, and predictive values. RESULTS: The authors assessed 1696 employees, of whom 22.0% were firefighters, 10.4% were police officers, 10.3% were maintenance workers, and 8.1% were administrative assistants. The seroprevalence of SARS-CoV-2 infection was 2.9% (95% CI: 2.1-3.7%). Administrative assistants comprised the professional group with highest seroprevalence of SARS-CoV-2 (OR = 1.9 in the comparison with other occupational groups, 95% CI: 0.8-4.3, p = 0.126). The seroprevalence of SARS-CoV-2 infection among those who were in direct contact with COVID-19 patients in their professional activity was 3.9%, compared to 2.7% among those who were not in direct contact with such patients (OR = 1.5, 95% CI: 0.8-2.8, p = 0.222). The highest risk of infection was associated with the presence of a confirmed SARS-CoV-2 infection in the household (OR = 17.4, 95% CI: 8.3-36.8, p < 0.001). Living with a healthcare professional was not associated with a higher risk of infection (OR = 1.0, 95% CI: 0.4-2.5, p = 0.934). Anosmia/ dysgeusia was the symptom with the highest positive predictive value (52.2%, 95% CI: 31.8-72.6, p < 0.001) and specificity (99.3%, 95% CI: 98.9-99.7, p < 0.001), while cough was the most prevalent symptom among SARS-CoV-2 seropositive participants (36%). CONCLUSIONS: The authors observed a SARS-CoV-2 seroprevalence of 2.9% among assessed municipal employees. Anosmia/dysgeusia was the COVID-19 symptom which displayed the highest positive predictive value and specificity. Int J Occup Med Environ Health. 2022;35(3):297-307.
Subject(s)
COVID-19 , SARS-CoV-2 , Anosmia , Antibodies, Viral , COVID-19/epidemiology , Dysgeusia , Epidemiologic Factors , Health Personnel , Humans , Portugal/epidemiology , Seroepidemiologic StudiesABSTRACT
BACKGROUND: COVID-19 antibody testing has been shown to be predictive of prior COVID-19 infection and an effective testing tool. The CLUNGENE® SARS-COV-2 VIRUS (COVID-19) IgG/IgM Rapid Test Cassette was evaluated for its utility to aide healthcare professionals. METHOD: Two studies were performed by using the CLUNGENE® Rapid Test. (1) An expanded Point-of-Care (POC) study at two clinical sites was conducted to evaluate 99 clinical subjects: 62 positive subjects and 37 negative subjects were compared to RT-PCR, PPA, and NPA (95% CI). Sensitivity was calculated from blood-collection time following symptom onset. (2) A cross-reactivity study was performed to determine the potential for false-positive results from other common infections. RESULTS: The specificity of subjects with confirmed negative COVID-19 by RT-PCR was 100% (95% CI, 88.4-100.0%). The sensitivity of subjects with confirmed positive COVID-19 by RT-PCR was 96.77% (95% CI, 88.98-99.11%). In the cross-reactivity study, there were no false-positive results due to past infections or vaccinations unrelated to the SARS-CoV-2 virus. CONCLUSION: There is a need for a rapid, user-friendly, and inexpensive on-site monitoring system for diagnosis. The CLUNGENE® Rapid Test is a useful diagnostic test that provides results within 15 min, without high-complexity laboratory instrumentation.
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Serological testing of large representative populations for antibodies to SARS-CoV-2 is needed to estimate seroprevalence, transmission dynamics, and the duration of antibody responses from natural infection and vaccination. In this study, a high-throughput SARS-CoV-2 multiplex microsphere immunoassay (MMIA) was developed for the receptor binding domain (RBD) and nucleocapsid (N) that was more sensitive than enzyme-linked immunosorbent assay (ELISA) (98% versus 87%). The MMIA was then applied and validated in 264 first responders in Colorado using serum and dried blood spot (DBS) eluates, compared to ELISA, and evaluated for neutralizing antibodies. Four percent (11/264) of first responders were seropositive in July to August 2020. Serum and DBS were highly correlated for anti-RBD and anti-N antibodies (R = 0.83, P < 0.0001 and R = 0.87, P < 0.0001, respectively) by MMIA. The MMIA accurately predicted SARS-CoV-2 neutralizing antibodies using DBS (R = 0.76, P = 0.037). On repeat antibody testing 3 months later, anti-RBD IgG decreased less rapidly than anti-N IgG measured by MMIA, with a median change in geometric median fluorescence intensity of 62% versus 79% (P < 0.01) for anti-RBD and anti-N IgG, respectively. This novel MMIA using DBS could be scalable for rapid and affordable SARS-CoV-2 serosurveillance in the United States and globally.