Define Very Major Error in AST method comparison.

Define Very Major Error in AST method comparison.

• A. A susceptible result by the test when the reference method shows resistant.
• B. A resistant result by the test when the reference method shows susceptible.
• C. A resistant result by the test when the reference method shows susceptible.
• D. A result that falls exactly on the breakpoint.

Answer: (C)

Very Major Error occurs when the test method reports a susceptible result for an organism that is actually resistant by the reference method. This means a resistant isolate is misclassified as susceptible, which can lead to ineffective therapy and spread of resistance. The option that describes a susceptible result by the test when the reference shows resistant captures this dangerous misclassification. In contrast, labeling a test as resistant when the reference shows susceptible defines a Major Error, which is serious but not as clinically dangerous as a VME. A result lying exactly at the breakpoint isn’t by itself an error type.

Very Major Error occurs when the test method reports a susceptible result for an organism that is actually resistant by the reference method. This means a resistant isolate is misclassified as susceptible, which can lead to ineffective therapy and spread of resistance. The option that describes a susceptible result by the test when the reference shows resistant captures this dangerous misclassification. In contrast, labeling a test as resistant when the reference shows susceptible defines a Major Error, which is serious but not as clinically dangerous as a VME. A result lying exactly at the breakpoint isn’t by itself an error type.