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Orthopoxviruses (human monkeypox virus) (hMPXV)

Disease Information

Orthopoxviruses are a family of viruses that includes hMPXV (human monkeypox virus), variola virus (which causes smallpox), vaccinia virus (used in the ACAM2000 live, attenuated smallpox vaccine), cowpox virus, and other viruses. hMPXV has recently been spreading in many countries, including the United States, that have not historically reported infections with this virus.
There are two genetic clades of hMPXV. In an effort to avoid stigma and discrimination against people from the areas after which these two strains were named, we refer to them as hMPXV-1, which is typically more severe and has a case-fatality rate of up to 10% and hMPXV-2, which causes milder illness, with an estimated case fatality rate in endemic countries of 1% (though it might be higher in immunocompromised persons). The 2022 outbreak involving non-endemic countries is caused by hMPXV-2.

hMPXV Disease Outbreak Deterimination

Disease Reporting

For Health Care Providers and Clinical Laboratories

Health care providers and clinical laboratories are required by law to report confirmed and probable (presumptive) cases of hMPXV to the local public health authority immediately.