Alternative sampling specimens for the molecular detection of mpox (formerly monkeypox) virus

Area of Science:

• Virology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Mpox (formerly monkeypox) is a viral disease caused by the mpox virus (MPXV).
• Current diagnostic guidelines recommend skin lesions for mpox confirmation.
• The utility of alternative specimens like oropharyngeal swabs and saliva requires further investigation.

Purpose of the Study:

• To evaluate the diagnostic sensitivity of alternative specimen types for mpox virus (MPXV) detection.
• To compare the performance of EDTA plasma, oropharyngeal swabs, and saliva for MPXV PCR testing.

Main Methods:

• MPXV PCR testing was performed on EDTA plasma, oropharyngeal swabs, and saliva from 25 patients with confirmed mpox skin lesions.
• Diagnostic sensitivity and viral loads were compared across the tested specimen types.

Main Results:

• Saliva demonstrated the highest diagnostic sensitivity (88%) for MPXV detection.
• EDTA plasma showed 80% sensitivity, while oropharyngeal swabs had 64% sensitivity.
• Significantly higher MPXV viral loads were observed in saliva compared to other specimens.

Conclusions:

• Saliva is a highly sensitive specimen for mpox laboratory confirmation and may be a valuable alternative to oropharyngeal swabs.
• The findings suggest revising WHO guidelines to include saliva testing, especially in the absence of skin lesions.
• The high viral load in saliva warrants further investigation into its role in mpox transmission.