06/02/2022: Lab Advisory: CLARIFICATION – CDC Publishes Non-variola Orthopoxvirus PCR Testing Procedure

CDC's Laboratory Outreach Communication System (LOCS)

Audience: Clinical Laboratory Professionals

Level: Laboratory Advisory

Earlier today, the CDC Laboratory Outreach Communication System (LOCS) issued a Laboratory Advisory about CDC’s Real-Time PCR test procedure to detect Non-variola Orthopoxvirus. Please refer to the bold + italic text in this follow-up message for clarification about the assay.


On May 30, 2022, CDC published a Real-Time PCR test procedure to detect Non-variola Orthopoxvirus. This procedure is intended for international partners and any laboratories interested in pursuing a Laboratory Developed Test (LDT). This procedure includes sequence information for primer and probe development and cycling conditions.

This assay is designed to detect non-variola orthopoxviruses, including mpox virus. It is not intended to specifically detect mpox virus or to differentiate mpox virus from the other orthopoxviruses this assay detects. Clinical presentation and positive test results from a Non-variola Orthopoxvirus assay is adequate for treatment and laboratories should notify the appropriate state or territorial public health authorities of positive results.

Public health laboratories have capacity for the current testing demand. Laboratories with specimens that are suspected to contain mpox virus should contact their state or territorial public health department (contact list) as soon as possible. Please refer to the CDC Specimen Collection Guidelines for Mpox Virus for more information.

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Online resources:


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 (CDC)