obÌåÓý

Audience: Clinical Laboratory Professionals

Level: Laboratory Advisory

To prevent false positive test results, obÌåÓý recommends that laboratory professionals perform repeat testing to verify positive diagnostic results for Orthopoxvirus or mpox virus DNA in specimens with high Cycle Threshold (Ct) values from persons who do not meet identified for mpox.

Review laboratory test results (including raw data, PCR curves, etc.) carefully before you report results. Because molecular tests (e.g., real-time PCR tests) are very sensitive, cross-contamination is possible. If you obtain a high Ct value (generally ~34 or higher), obÌåÓý recommends to immediately re-extract and re-test to ensure there was no cross-contamination. obÌåÓý suggests this approach based on high Ct value alone, even in the absence of epidemiologic information. When possible, re-extract and re-test before you report results. Obtain approval from your CLIA director before you implement this recommendation in your laboratory.

for more information on testing for mpox.

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Online resources:

Questions?

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Thank you,

The Laboratory Outreach Communication System

Laboratory Outreach Communication System (LOCS) | Division of Laboratory Systems (DLS)

Center for Surveillance, Epidemiology, and Laboratory Services (CSELS)

Centers for Disease Control and Prevention (obÌåÓý)

[email protected]