Test description
- Detection of mpox virus by real-time PCR.
- In case of a positive result, clade typing would be performed.
Aim of the test
Mpox diagnosis and typing for epidemiological surveillance purposes.
Criteria to perform this test in the context of reference activities
- Suspecting infection by mpox virus based on clinical presentation and exposition.
- The interval between the onset of symptoms and the collection of the sample must be stated on the application form.
- Clinical and epidemiological information must be stated on the application form.
Instructions about the sample
Sampling
Mpox can be diagnosed from different types of samples. The reliability of the results depends on the clinical picture. If the patient has lesions, PCR on a swab taken from the lesions is the most reliable.
In general, a single type of sample is sufficient. In the case of an atypical clinical presentation or suspected low viral load, an additional sample (of a different type of sample) may be useful.
Sampling of lesions:
Performing a swab on lesions, preferentially in combination with an anorectal swab if the patient is an MSM. It is preferable to sample more than one lesion, preferentially at different locations of the body and/or on lesions of different aspects.
Other samples/swabs depending on the clinical picture:
- Swab of mucous lesions (e.g. in the mouth)
- Anorectal swab in case of anal symptoms
- Saliva or throat swab in case of tonsilitis
- Urine or urethral swab in cases of urethritis.
In the prodromal phase, saliva or a throat swab, and possibly whole blood/serum/plasma EDTA, may be useful.
Storage conditions
- Place the swab immediately in a sterile tube with antibiotic-free viral transport medium.
- If samples can be analysed within 48 hours of collection, keep them refrigerated (4-8°C).
- If analysis can only be performed after more than 48 hours, store samples at at least -20°C. Samples should be kept cold or frozen within one hour of collection and sent to the laboratory as soon as possible. Avoid freezing and thawing these samples.
Transport instructions
A. Transport conditions
- Send samples with melting ice or freezing gel packs if stored in the refrigerator. If stored between -20°C and -70°C, send them on dry ice.
- As this is a biosafety level 3 pathogen, samples must be disinfected externally and placed in a bag that is itself disinfected externally.
- Samples should be shipped UN3373 in triple packaging by courier.
- All samples must be sent with their respective application form to the NRC. If the application form is missing, the analysis will not be carried out.
B. Specification of transport medium
Preferably use a swab in a tube containing inactivation medium. The following media have been validated for MPXV PCR:
- InActiv Blu (Fertipro)
- VTM-N (Nal von Minden)
- Cobas PCR Media Kit
If these media are not available, a skin swab in universal transport medium (UTM) or an eSwab can be sent.
Unaccepted requests
The analysis will not be performed if:
- Inappropriate type of sample or insufficient sample
- Smears with metal or wooden rods, or with a piece of cotton will be rejected.
- Missing or incomplete application form
Turn-around time (and frequency of analysis)
- Detection : 2 working days
- Typing : 7 working days
Communication of test results
The report will be sent by fax, post or e-mail.
Note: Detection is accredited, typing isn’t accredited.