Most state health department laboratories and others participating in the Laboratory Response Network are equipped to test clinical specimens for the presence of nonvariola Orthopoxvirus
On July 9, the Virginia Laboratory Response Network tested lesion scrapings from the patient using real-time polymerase chain reaction and detected the presence of nonvariola orthopoxvirus
Novel human poxvirus infections identified in the 21st century have often been presumed to have animal origins; for example, an investigation of a novel poxvirus isolated from 2 men in the country of Georgia revealed serologic evidence of orthopoxvirus
exposure in cows in their herd and in captured rodents (5).
Viral analysis of the swab by multiple real-time polymerase chain reaction (PCR) assays for orthopoxvirus
and vaccinia yielded evidence of viral DNA; viral culture was positive for orthopoxvirus
MPX, a zoonotic orthopoxvirus
, is a public health priority in regions of endemicity in West and Central Africa because of its clinical severity and potential for epidemic spread (1).
The last case of naturally acquired smallpox disease, caused by the orthopoxvirus
variola virus (VARV), occurred in 1977, and the last laboratory-acquired case occurred in 1978.
Human monkeypox is a rare zoonotic infection caused by an orthopoxvirus
and characterized by smallpox-like signs and symptoms (1).
Vaccinia virus (VACV), the prototype virus of the genus Orthopoxvirus
, has been associated with exanthematic outbreaks in Asia and South America that affect mainly dairy cattle and rural workers (3,4).
On March 8, lesion specimens were analyzed at the Illinois Department of Public Health Laboratory (IDPHL) in Chicago by real-time polymerase chain reaction (PCR) orthopoxvirus
generic assay and nonvariola orthopoxvirus
virions are brick-shaped and replicate in the cytoplasm of eukaryotic cells (1).
Laboratory confirmation of orthopoxvirus
infections, including vaccinia, requires test methods that are not commercially available.
(OPV)-specific PCR showed negative results (6); a parapoxvirus (PPV)-specific PCR (6), a leporipoxvirus-specific PCR (A.