Reducing False Negative PCR Test for COVID-19

False Negative Fecal Occult Blood Test: Prozone Effect

Dear editor, the fecal occult blood test is the presently widely used screening laboratory test for colorectal cancer. At present, the test is usually based on an immunological diagnostic principle (1, 2). A false positive fecal occult blood is common and widely mentioned in literature. Nevertheless, the false negative is little mentioned in the paper. Here, the authors discuss the issue of the...

False-negative HIV antibody test results.

Ideally HIV antibody tests have to be both extremely sensitive and able to recognize all known HIV subtypes. Three patients whose sera failed to react with a synthetic oligopeptide-based HIV antibody test are described in this report. The patients were a Pakistani male infected recently, an Australian male infected for several years, and a Ugandan woman with AIDS. The presence of anti-HIV antib...

COVID-19 in Nursing Homes: The Problematic Management of Residents Without Positive COVID-19 RT-PCR

The "false negative" treadmill exercise test and left ventricular dysfunction.

One hundred and fifteen consecutive symptomatic patients undergoing graded exercise testing, selective coronary angiography and left ventriculography were retrospectively evaluated. The sensitivity, specificity, and false negative response rates of the exercise tests were 79%, 81%, and 21%, respectively. Although the magnitude of a positive ST-segment response was related to more extensive vasc...

'False-positive' and 'false-negative' test results in clinical urine drug testing.

The terms 'false-positive' and 'false-negative' are widely used in discussions of urine drug test (UDT) results. These terms are inadequate because they are used in different ways by physicians and laboratory professionals and they are too narrow to encompass the larger universe of potentially misleading, inappropriate and unexpected drug test results. This larger universe, while not solely com...