scholarly journals Evaluation of Three Commercial Interferon-γ Assays in a Bovine Tuberculosis Free Population

2021 ◽  
Vol 8 ◽  
Author(s):  
Giovanni Ghielmetti ◽  
Patricia Landolt ◽  
Ute Friedel ◽  
Marina Morach ◽  
Sonja Hartnack ◽  
...  
Keyword(s):  
False Positive ◽  
Bovine Tuberculosis ◽  
Interferon Γ ◽  
Positive Test ◽  
Positive Test Result ◽  
False Positive Test ◽  
Increased Risk ◽  
Positive Results ◽  
Test Result ◽  
Free Status

The interferon-γ assay has been used worldwide as an ancillary test for the diagnosis of bovine tuberculosis (bTB). This study aimed to describe, based on the bTB-free status in Switzerland, the difference of applying a more stringent cutoff point of 0.05 compared with 0.1 for bTB surveillance. Moreover, the effect of time between blood collection and stimulation, culture results, optical density values, and the influence of testing different breeds were evaluated. Blood samples from a total of 118 healthy cows older than 6 months were tested with three commercial interferon-gamma assays. To confirm the bTB-free status of the tested animals and to investigate potential cross-reactions with nontuberculous mycobacteria, pulmonary and abdominal lymph nodes in addition to ileal mucosa from each cattle were used for the detection of viable Mycobacteria spp. by specific culture. Significant differences regarding the proportion of false-positive results between the two Bovigam tests and between Bovigam 2G and ID Screen were found. Samples analyzed with Bovigam 2G were 2.5 [95% confidence interval (CI) 1.6–3.9] times more likely to yield a false-positive test result than samples analyzed with Bovigam TB. Similarly, the odds ratio (OR) for testing samples false-positive with ID Screen compared with Bovigam TB was 1.9 (95% CI 1.21–2.9). The OR for testing false-positive with ID Screen compared with Bovigam 2G was less to equally likely with an OR of 0.75 (95% CI 0.5–1.1). When using a cutoff of 0.05 instead of 0.1, the OR for a false-positive test result was 2.2 (95% CI 1.6–3.1). Samples tested after 6 h compared with a delayed stimulation time of 22–24 h were more likely to yield a false-positive test result with an OR of 3.9 (95% CI 2.7–5.6). In conclusion, applying a more stringent cutoff of 0.05 with the Bovigam 2G kit generates a questionable high number of false-positive results of one of three tested animals. Furthermore, specific breeds might show an increased risk to result false-positive in the Bovigam 2G and the ID Screen assays.

Abstract 2585: Mammography screening adherence after a false positive test result

2016 ◽  
Author(s):  
Mary W. Marsh ◽  
Thad Benefield ◽  
Mikael Anne Greenwood-Hickman ◽  
Laura Jones ◽  
Anne Marie Meyer ◽  
...  
Keyword(s):  
False Positive ◽  
Mammography Screening ◽  
Positive Test ◽  
Positive Test Result ◽  
False Positive Test ◽  
Screening Adherence ◽  
Test Result

Benzathine as a cause for a false-positive test result for amphetamines

1995 ◽  
Vol 127 (4) ◽  
pp. 669-670 ◽  
Author(s):  
Michel Berthier ◽  
Dominique Bonneau ◽  
Patrick Mura ◽  
Alain Piriou ◽  
Denis Oriot
Keyword(s):  
False Positive ◽  
Positive Test ◽  
Positive Test Result ◽  
False Positive Test ◽  
Test Result

scholarly journals A Positive Attitude to Negate a False Positive Test Result: An Intern’s Experience with COVID-19

2020 ◽  
Author(s):  
Vanessa N. Youmbi
Keyword(s):  
False Positive ◽  
Positive Attitude ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Positive Test ◽  
Psychological Interventions ◽  
Test Results ◽  
Positive Test Result ◽  
False Positive Test ◽  
Test Result

I recount my experience as an intern in the Democratic Republic of Congo during the COVID-19 pandemic. I received a patient who was presumed to have COVID and was isolated. The first test result was a false positive, so I was discharged. Although I was not infected by COVID-19, I was adversely affected by it. The anxiety of waiting for test results and isolation are both mentally challenging. Also, COVID-related stigmatization is a serious complication of the disease. Targeted psychological interventions should prevent all three.

scholarly journals False Positive Anti-Hepatitis A Virus IgM Result in a Patient with Autoimmune Hepatitis

1989 ◽  
Vol 3 (3) ◽  
pp. 115-118 ◽  
Author(s):  
James R. Gray ◽  
Urs P. Steinbrecher
Keyword(s):  
Autoimmune Hepatitis ◽  
False Positive ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Positive Test Result ◽  
Acute Hepatitis A ◽  
Diagnostic Confusion ◽  
Immunoglobulin Levels ◽  
Positive Results ◽  
Test Result

This report describes a patient with autoimmune hepatitis in whom a positive test result for hepatitis A virus (HAV) IgM antibody led to diagnostic confusion until it was shown to be false positive by immunoprecipitation of IgG from serum. The mechanism for the false positive result may have been related to marked hypergammaglobulinemia, as serum obtained after normalization of immunoglobulin levels tested negative. However, several other mechanisms were also considered. This case illustrates that the possibility of false positive results with the anti-HAV lgM assay should be kept in mind when the clinical features of the illness are not suggestive of acute hepatitis A.

scholarly journals Differences in COVID-19 Testing and Test Positivity Among Veterans, United States, 2020

2021 ◽  
pp. 003335492110094
Author(s):  
Jacqueline M. Ferguson ◽  
Hoda S. Abdel Magid ◽  
Amanda L. Purnell ◽  
Mathew V. Kiang ◽  
Thomas F. Osborne
Keyword(s):  
United States ◽  
African American ◽  
Low Income ◽  
The United States ◽  
Positive Test ◽  
Health Administration ◽  
Positive Test Result ◽  
Black African ◽  
Increased Risk ◽  
Test Result

Objective COVID-19 disproportionately affects racial/ethnic minority groups in the United States. We evaluated characteristics associated with obtaining a COVID-19 test from the Veterans Health Administration (VHA) and receiving a positive test result for COVID-19. Methods We conducted a retrospective cohort analysis of 6 292 800 veterans in VHA care at 130 VHA medical facilities. We assessed the number of tests for SARS-CoV-2 administered by the VHA (n = 822 934) and the number of positive test results (n = 82 094) from February 8 through December 28, 2020. We evaluated associations of COVID-19 testing and test positivity with demographic characteristics of veterans, adjusting for facility characteristics, comorbidities, and county-level area-based socioeconomic measures using nested generalized linear models. Results In fully adjusted models, veterans who were female, Black/African American, Hispanic/Latino, urban, and low income and had a disability had an increased likelihood of obtaining a COVID-19 test, and veterans who were Asian had a decreased likelihood of obtaining a COVID-19 test. Compared with veterans who were White, veterans who were Black/African American (risk ratio [RR] = 1.23; 95% CI, 1.19-1.27) and Native Hawaiian/Other Pacific Islander (RR = 1.13; 95% CI, 1.05-1.21) had an increased likelihood of receiving a positive test result. Hispanic/Latino veterans had a 43% higher likelihood of receiving a positive test result than non-Hispanic/Latino veterans did. Conclusions Although veterans have access to subsidized health care at the VHA, the increased risk of receiving a positive test result for COVID-19 among Black and Hispanic/Latino veterans, despite receiving more tests than White and non-Hispanic/Latino veterans, suggests that other factors (eg, social inequities) are driving disparities in COVID-19 prevalence.

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