Mpox is a viral disease that can cause severe illness and death and is now spreading between people around the world.
LESION PROGRESSION
Diagnosing mpox requires an understanding of the stages of lesion progression.
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Rash: The most common manifestation of mpox.
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Location: Lesions can appear anywhere on the body, including the face, hands, feet, genitals, and mucous membranes.
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Progression: Lesions typically progress through six distinct stages over 2-4 weeks.
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Development: Different lesions may be at varying stages of development simultaneously.
Source: National STD Curriculum, project funded by the Centers for Disease Control and Prevention.
DIAGNOSTIC TESTING IN THE U.S.
In the United States, 23 manufacturers currently provide mpox tests (FIND, 2024). Additionally, new testing methods, such as Next-Generation Sequencing (NGS), antigen detection, and serological tests, are under development to further enhance diagnostic capabilities.
Current Testing Methods
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Polymerase Chain Reaction (PCR) – PCR tests are the preferred way to diagnose mpox and are commonly used for Clade IIb mpox. The qPCR test from Quest Diagnostics (2023) is popular as it allows testing from lesion crusts rather than requiring lesion fluid.
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Clade-Specific Testing — In the U.S., four manufacturers produce tests for Clade I; however, only one test can inform clinical care. Limited availability poses a potential risk if the more severe Clade I spreads to non-endemic regions. For Clade II, multiple, well-supported testing options are available across the U.S.