The Centers for Disease Control and Prevention (CDC) released specimen collection guidelines and PCR test procedures for monkeypox virus on May 31. The CDC recommended that laboratories with suspected monkeypox virus specimens contact their state or territorial public health department (contact list) or the CDC Emergency Operations Center (EOC) at 770-488-7100 for guidance. Additionally, the CDC published a Real-Time PCR test procedure to detect non-variola orthopoxvirus.

The CDC provided the following guidelines for clinical laboratories when collecting specimens for suspected monkeypox virus:

• Collect at least two dry swabs from the same lesion.
• Swab or brush lesion vigorously with two separate sterile dry swabs. Use a sterile nylon, polyester, or Dacron swab with plastic, wood, or thin aluminum shaft. Do not use other types of swabs.
• Place swabs in individual sterile containers. Do not add any transport media.
• Refrigerate (2–8°C) or freeze (-20°C or lower) specimens within an hour after collection. Store refrigerated specimens for up to 7 days and frozen specimens for up to 60 days.
• Send refrigerated specimens within seven days of collection, and ship frozen specimens within 60 days of collection. Specimens that are greater than 8°C upon receipt will be rejected. Ship on dry ice as category B.
• Send both swabs to the state or territorial public health laboratory. All specimens should be sent through the state or territorial public health department unless authorized to send them directly to CDC.
• A state public health laboratory may test one of the paired dry swabs for presumptive results. In addition, CDC can provide monkeypox virus-specific testing on the second dry swab specimen if the first dry swab is non-variola orthopoxvirus positive at the state or territorial public health laboratory.

After consultation, laboratories can send appropriately collected specimens to their state or territorial public health laboratory for real-time polymerase chain reaction (PCR) testing. For more information, see the CDC Laboratory Process for Monkeypox Virus Testing.

Public health laboratories have the capacity for the current testing demand; but released their testing procedures in the event additional testing is needed.

The CDC real-time PCR test procedure to detect non-variola orthopoxvirus 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 the monkeypox virus. It is not intended to specifically detect monkeypox virus or differentiate monkeypox virus from the other orthopoxviruses this assay detects. Clinical presentation and positive test results from a non-variola orthopoxvirus assay are adequate for treatment, and laboratories should notify the appropriate state or territorial public health authorities of positive results.