CDC establishes specimen collection guidelines after confirmed U.S. monkeypox virus

June 2, 2022

The Massachusetts Department of Public Health and the U.S. Centers for Disease Control and Prevention (CDC) are investigating a confirmed case of monkeypox virus in the United States, according to a news release.

Testing at CDC on May 18, 2022 confirmed that the patient was infected with a West African strain of monkeypox virus. The patient is currently isolated and does not pose a risk to the public.

CDC specimen collection guidelines for monkeypox virus:

Laboratories with specimens that are suspected to contain monkeypox virus should contact their state or territorial public health department (contact list) or the CDC Emergency Operations Center (EOC) at 770-488-7100 for guidance. After consultation, laboratories can send appropriately collected specimens to their state or territorial public health laboratory for real-time polymerase chain reaction (PCR) testing.

Clinical laboratories should follow these guidelines when collecting specimens for 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 a 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 7 days of collection; 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. 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.

Visit CDC for the guidelines

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