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Test Menu Details


Orthopoxvirus, Real-Time PCR

Updated

4/1/2025

Search Terms Variola; Smallpox; Vaccinia; Cowpox; hMPXV; Monkeypox; Camelpox; Ectromelia; Gerbilpox; Mpox; Poxvirus
How to Order

Submit one Virology/Immunology Test Request Form (OHA0042) per specimen. In the “Molecular” section, check the "Other" box and write in "Orthopox PCR."

Availability

All clients caring for patients meeting the CDC Case Definition for Mpox. OSPHL does not collect specimens from patients but accepts specimens from healthcare providers. 

OSPHL is currently not able to identify mpox or determine mpox clades. If your patient presents with mpox-like symptoms and has a travel history to a country with known Clade I transmission, or if you have a reason to suspect a patient is infected with a non-mpox Orthopox species, contact the OHA Acute and Communicable Disease Prevention Section Immediately at 971-673-1111.

Note: OSPHL does not perform testing for specimens deemed “High risk” for smallpox, which would be immediately sent out for referral.

Performed

As needed

Time to Reporting

Within 3 working days after receipt of specimen.

CPT Code 87798


Specimen Collection Details

Collection
Collect two dry lesion swabs from the same lesion. Use sterile nylon, polyester, or Dacron swabs with plastic or aluminum shafts. Swab or brush lesion vigorously with two separate dry swabs. Place each swab in a separate sterile container (one swab per container). DO NOT ADD VTM OR UTM TO CONTAINERS.

If possible, repeat the collection procedure for an additional lesion site.

See the CDC Guidelines for Collecting and Handling Specimens for Mpox Testing for more instructions.

Label each specimen with at least two unique patient identifiers and a brief description of the lesion location. 
Optimal Volume

2-4 separate, dry lesion swabs

Minimum Volume

2 dry lesion swabs from the same lesion

Handling

Refrigerate (2-8°C) or freeze (-20°C or lower) specimens within an hour after collection. Store refrigerated for up to 7 days and frozen up to 60 days.  Handle as infectious agent using universal precautions.  

Refer to biosafety measures for collection and handling of suspected Orthopox patients and specimens.   

Transport

Refrigerated specimens should be transported with cold packs and frozen with dry ice. 

Transport for receipt at OSPHL as soon as possible after collection. 

Rejection Criteria

Specimens are subject to the requirements of the OSPHL Specimen Submission Policy (pdf).

Comments If you have reason to suspect a patient is infected with another Orthopox species, or your patient presents with mpox-like symptoms with travel history to a country with known Clade I transmission, contact the OHA Acute and Communicable Disease Prevention Section immediately at 971-673-1111. Specimens approved for clade-specific testing will be tested at the Washington Public Health Laboratory using either the Orthopox or Mpox-specific assay.

Specimens suspected of being mpox Clade I will not be tested at OSPHL and will be immediately referred to a reference laboratory for testing.

OSPHL does not perform testing for specimens deemed “High Risk" for smallpox, which would be immediately sent out for referral.

OSPHL Orthopox PCR results may be the only result received. OSPHL no longer sends every Orthopox-positive PCR to CDC for speciation when monkeypox is suspected. CDC notes that mpox Clade II is currently the only Orthopoxvirus virus circulating in the United States. In alignment with CDC guidance, OSPHL will send a sub-set of Orthopox-positive specimens to CDC for public health surveillance.

OSPHL utilizes CDC's Orthopoxvirus PCR procedure and CDC's FDA cleared non-variola Orthopoxvirus DNA PCR assay. Both assays will detect the members of the Orthopox genus such as vaccinia, cowpox, monkeypox (mpox), camelpox, ectromelia, and gerbilpox, but neither assay will differentiate between the species. Neither test will detect molluscum or orf virus.

Testing may be paired with PCR for Vaccinia and/or Varicella Zoster virus.

Original material submitted for testing is retained for 7 calendar days after receipt at the laboratory.

Method Details

Methodology
LRN Reference real-time Polymerase Chain Reaction (PCR)
Performance
Specifications
Method performance specifications determined by the Centers for Disease Control and Prevention (CDC). Please contact the CDC for specifications if needed.

Change Log

4/1/2025
Updated Search Terms; How to Order; Availability; Performed; Minimum Volume; Comments
5/23/2023
Reviewed; no changes