For Healthcare Professionals
Testing Recommendations
Healthcare providers should test any patients with suspected Mpox. This includes any patient with a new characteristic rash or patients with risk factors for Mpox and a new rash. The rash associated with Mpox can be confused with other rashes encountered in clinical practice including herpes, syphilis, and varicella and co-infections have been reported. Providers should wear appropriate personal protective equipment (PPE) to collect specimens (see Infection Control guidance below).
Patients presenting with perianal or genital ulcers, diffuse rash, or proctitis should also be evaluated for STIs. However, the diagnosis of an STI does not exclude Mpox as a concurrent infection may be present. The clinical presentation of Mpox may be similar to some STIs, such as syphilis, herpes, lymphogranuloma venereum (LGV), or other etiologies of proctitis.
Commercial testing is available
Commercial testing for Mpox continues to expand. Testing is now available through Quest Diagnostics, LabCorp, Aegis Sciences and Mayo Clinic Laboratories. LabCorp, Mayo Clinic Laboratories, and Aegis Sciences are using the CDC’s orthopoxvirus test (which detects all non-smallpox related orthopoxviruses, including Mpox). The Quest assay is real time PCR test developed by Quest that detects DNA of non-variola orthopoxviruses and Mpox virus (West African clade)—see Quest FAQs. CDC anticipates additional commercial laboratories will come online this month.
Providers should submit specimens through commercial labs if possible. Follow specimen collection instructions provided by the laboratory. Public health approval is not required to submit specimens to a commercial lab, however providers should notify public health about patients suspected to have Mpox without waiting for results to return to allow for contact tracing efforts to begin expeditiously.
Providers using commercial labs must report all Riverside County residents with orthopoxvirus positive and/or presumptive positive test results (see Reporting).
Public Health Laboratory
Providers that do not have access to commercial orthopoxvirus testing, may request testing for suspected cases by submitting a Mpox intake form and photos of the rash/lesions via secure email to bcole@ruhealth.org
Testing Guidance
If a patient is evaluated and Mpox is high on the differential diagnosis, collect two swabs from two different lesions for preliminary and confirmatory testing as follows:
- Vigorously swab or brush lesion with two separate sterile dry polyester or Dacron swabs. (two from each lesion)
- Break off end of applicator of each swab into a sterile 1.5- or 2-mL screw-capped tube with O- ring or place 2 entire swabs in 2 separate sterile containers. Do not add or store in viral or universal transport media.
- The two separate sterile containers should be placed in 2 separate biohazard bags and refrigerated at 4C.
Specimens being tested through Public Health, will be picked by a RUHS courier, within 24 hours Monday through Friday. Store specimens at -80C if it is greater than 72 hours between specimen collection and pickup.
Swabs can be collected and stored at the proper temperature without waiting to discuss the case with Public Health. This will avoid outpatients needing to be recalled should they meet criteria for testing through Public Health.
