Mpox virus (Monkeypox)

Updated 09/25/24, 9:00 am

 

Testing for Mpox is available in several national reference laboratories and at the WSLH. Refer to CDC and Wisconsin resources for guidance on which patients to test.

 

Resources

  • CDC Monkeypox webpage
  • CDC Health Alert Network Messages:
    • HAN 516: Prevention Strategies for Mpox, including Vaccinating People at Risk via Sexual Exposure, for U.S. Travelers Visiting Countries with Clade I Mpox Outbreaks
    • HAN 466: Monkeypox Virus infection in the United States and other non-endemic countries.
    • HAN 468: Updated Case-finding Guidance: Monkeypox Outbreak – United States, 2022.
    • HAN 471: Update for Clinicians on Testing and Treatment for Monkeypox
    • HAN 501: Mpox Caused by Human-to-Human Transmission of Monkeypox Virus with Geographic Spread in the Democratic Republic of the Congo
    • HAN 513: Mpox Caused by Human-to-Human Transmission of Monkeypox Virus in the Democratic Republic of the Congo with Spread to Neighboring Countries
  • MMWR: Epidemiologic and Clinical Characteristics of Monkeypox Cases, August 5, 2022
  • Wisconsin DHS Monkeypox webpage and Monkeypox resource
  • Wisconsin DHS Health Alert Network Messages:
    • HAN #44: Monkeypox: Recommendations for Detection and Reporting
    • HAN #46: Monkeypox Detected in Wisconsin Resident
    • HAN #47: Expanded Monkeypox testing.
  • APHL Monkeypox Biosafety Fact sheet for laboratorians

 

Public Health Testing Eligibility

  • Patients must have lesions and symptoms consistent with Mpox and meet one or more of the following public health testing criteria to qualify for fee-exempt testing at the Wisconsin State Laboratory of Hygiene.
    • Patient is uninsured or underinsured (for whom cost would pose a barrier to getting tested).
    • The patient’s clinician is unable to send specimens to one of the commercial or clinical labs conducting Mpox testing.
    • Patient is a known contact to a Mpox case.
    • Patient reported skin-to-skin contact with someone in a social network experiencing Mpox activity; this includes men who have sex with men.
    • Other priority testing as authorized by DHS.
  • Note: If testing is needed on a patient not meeting these criteria, please consider testing at a reference laboratory. These specimens will not be tested or forwarded by Wisconsin State Laboratory of Hygiene (WSLH).

Specimen Collection

  • Collect two swabs from at least one lesion. If possible, submit paired swab specimens from multiple lesions on different body parts and with different appearances. A swab pair can be used for multiple lesions. Do not exceed 3 sets of swabs per patient.
  • Swab lesions vigorously. Specimens that do not contain enough human DNA may lead to inconclusive test results. Prevent sharps injury – do not use sharp instruments for Mpox virus lesion specimen collection. CDC collection guidance
  • Acceptable swab types include sterile nylon, polyester, rayon or dacron swabs with a synthetic shaft. (No cotton swabs or swabs with wooden shafts). We recommend using swabs with firm shafts to allow for adequate specimen collection, swabs with highly bendable shafts may not collect enough material for testing.
  • Swabs in VTM are preferred, but lesion crusts in dry containers or dry swabs are also accepted. Please note that specimens submitted in UTM are not acceptable at this time. Dry swabs are required for clade I specific diagnostic testing at CDC.
  • Break off and send swab ends, the handles are not needed. Place each swab or lesion crust in a separate sterile container and each container in a separate biohazard bag. Clearly label each specimen container with the patient name and date of birth, date and time of collection, the type of specimen collected and the exact body site it was collected from (important for identifying paired specimens). Ship unknown specimens as Category B. Mpox or clade specific positives must be shipped Category A and are subject to federal Select Agent regulations.
  • NOTE: Swab snapping instructional videos created for COVID testing may be helpful for Mpox testing submitters. Scroll down the WSLH COVID-19 web page to find the videos.

Testing

  • WSLH uses an RT-PCR test for non-variola orthopox viruses using CDC LRN protocols.
  • If a specimen tests positive for a non-variola orthopox virus WSLH will report the results to the submitter, WDHS, and the CDC. Based on currently circulating strains in the US, a positive result is currently presumptive for Clade II (West African) Mpox. If the patient is suspected to be infected with clade I, please notify us on the requisition form.
  • The second, paired specimen may be sent to the CDC for Mpox virus- specific testing. Please do not send specimen directly to the CDC. If a second swab is not submitted to WSLH there will be no Mpox specific testing at CDC. Clade I results can only be reported to the submitter if a dry swab (no VTM) is submitted.
  • All Mpox testing at WSLH is fee-exempt. The submitter and patient will not receive a bill.
  • Routine testing is available daily, Monday-Friday.

Storage

  • Refrigerate (2–8°C), or freeze (≤ -20°C) within an hour of collection. Refrigerated specimens can be tested up to 7 days after collection and frozen specimens up to 60 days. Specimens that are expired upon receipt at WSLH or CDC will be rejected.

Packaging and Transport

Submit all specimens with a completed Requisition Form A. Write in “Mpox” in the “other” section of the form. You can request forms from WSLH Clinical Orders at 1-800-862-1088 or WSLH Customer Service at 1-800-862-1013.

  • Place a completed Form A for each specimen in the outside pocket of each biohazard bag. DO NOT place the completed form inside the bag touching the specimen.
  • Package the specimen as Category B (UN3373 biological substance). Ship with frozen cold packs at a minimum, dry ice is strongly recommended.
    • Specimens received ≥8°C will be rejected.
    • Refrigerated specimens expire after 7 days but frozen specimen may be test up to 60 days post collection
  • Gold Cross courier service (1-800-990-9668) may be used to transport suspect Mpox specimens fee exempt to the WSLH.
    • Order by NOON for same-day pick-up for NEXT DAY delivery (Sun-Fri)
    • Specimen received on Saturday will be tested on Monday.
    • Please hold specimen (4 to -80C) on Saturday so they don’t sit in a warehouse over the weekend.

Specimen Rejection Criteria

  • Specimens received ≥8°C
  • Specimen received outside of the acceptable storage time limit
  • Specimens without 2 patient identifiers
  • Unvalidated specimen types (blood, saliva, calcium alginate swabs, cotton tips, or wood shafts)

CDD Customer Service Hours:

  • Monday-Friday: 7:45 AM – 4:30 PM

CDD Specimen Receiving Hours:

  • Monday-Friday: 6:00 AM – 4:30 PM
  • Saturday: 6:30 AM – 12:30 PM

Contact Information:

  • CDD Customer Service: 1-800-862-1013
  • Clinical Orders: 1-800-862-1088
  • Purple Mountain Courier: 1-715-839-9989