On Sept. 7, 2022, Quest Diagnostics announced that it had received emergency use authorization (EUA) from the U.S. Food and Drug Administration (FDA) for the company’s lab-developed molecular diagnostic test to aid in the diagnosis of infection with the Mpox virus. The EUA was the first granted to a commercially available mpox test in the United States.

The Quest Diagnostics Mpox Virus Qualitative Real-Time PCR (Quest Mpox PCR) is intended for the qualitative detection of Mpox virus (West African clade, clade II) DNA and non-variola Orthopoxvirus DNA in lesion swab specimens (i.e., swabs of acute pustular or vesicular rash) in universal viral transport media from individuals suspected of Mpox virus infection by their healthcare provider. Test results are intended to be used in conjunction with patient history and other diagnostic information, and results should not be used as the sole basis of treatment or other patient management decisions.

Quest launched the Quest Mpox PCR test nationwide on July 13, 2022. The company performs the test at its advanced laboratories in San Juan Capistrano, Calif., and, beginning last week, Chantilly, VA, for ready access for providers and patients on both coasts of the United States. New York’s Department of Health has approved the tests from both laboratories, enabling access for patients living in the state.

Developed with the understanding that viruses mutate, the Quest Mpox PCR test features the ability to detect two different DNA targets (Mpox and non-variola Orthopoxvirus DNA) to help protect against false negatives. On September 2, the Centers for Disease Control and Prevention issued a Lab Alert that certain mpox tests may fail to detect mpox infection when a rare deletion of the target gene (called tumor necrosis factor) occurs, and negative results for highly suspicious cases therefore require confirmation by the CDC or public health labs. The alert does not apply to the Quest Mpox PCR test, so Quest does not need to modify its test or refer specimens producing negative results to the CDC or public health labs for confirmation.

Mpox is a rare infectious disease typically occurring in parts of Africa. The West African clade (clade II) is the circulating virus in the current global outbreak. The first case of this virus in the United States was detected in May 2022. CDC recommends that anyone with mpox symptoms talk to their health care provider, even if they don’t think they had contact with someone who has mpox.