First Point-of-Care Test for Mpox Receives EUA From FDA

A point-of-care (POC) test (Xpert Mpox; Cepheid) for monkeypox (Mpox) has received emergency use authorization (EUA) from the FDA. The EUA occurred following the Secretary of Health and Human Service's declaration that circumstances exist justifying an EUA of in vitro diagnostics for detection and/or diagnosis of Mpox infection.¹

Under the EUA, the test is considered authorized for use in moderately complex POC settings using the company’s GeneXpert Xpress systems, which has an installed base of approximately 50,000 systems across 180 countries. Specifically, authorized POC settings under the EUA are those with CLIA Certificate of Waiver (CoW), Certificate of Registration (CoR), Certificate of Accreditation (CoA), or Certificate of Compliance (CoC).¹

"Thankfully, the threat of Mpox in the United States has decreased dramatically since last summer. However, it is still circulating in many parts of the world making it important for healthcare providers to be ready for its potential re-emergence," said David Persing, MD, PhD, EVP and chief scientific officer of Cepheid, in a press release. "Xpert Mpox runs on Cepheid's GeneXpert systems, which has the largest installed base of any PCR-based molecular diagnostic platform, making this new test a valuable component within a preparedness plan that could be deployed quickly wherever accurate and actionable information is needed."¹

Mpox, which is transmitted to humans from animals, is a type of virus that is called a viral zoonosis. The symptoms of Mpox are similar to that of smallpox, although clinically less severe.

In 1980, smallpox was eradicated, leading to the cessation of smallpox vaccinations. Since that time, Mpox has emerged as the key orthopoxvirus to watch for purposes of public health impact.^1,2

Primarily occurring in central and west Africa, Mpox originally arose in locations with proximity to tropical rainforests; however, the virus has been increasingly showing up in urban areas. Animal hosts include rope squirrels, tree squirrels, Gambian pouched rats, dormice, non-human primates, and other species.

Currently, despite the virus’ namesake, the natural history and origin of the virus remain unknown. To identify the reservoir and circulation process in nature, further research is needed.²

One of the key symptoms of Mpox infection is fever accompanied by a maculopapular rash, which often appears as small, raised spots. However, these symptoms are similar to those of many other illnesses, such as chickenpox, measles, bacterial skin infections, syphilis, herpes, and medication-associated allergies. For this reason, the WHO recommends that suspected cases of Mpox be confirmed with a test using a human lesion sample.²

Mpox was first identified in humans in 1970 in the Democratic Republic of the Congo; the first known patient infected with the virus was a 9-month-old boy. Since 1970, most cases of Mpox are reported as occurring in rural, rainforest regions of the Congo Basin, particularly in the Democratic Republic of the Congo; however, cases of infection among humans have increasingly occurred across central and west Africa.²

In 2003, the first monkeypox outbreak outside of Africa was in the United States and was linked to human contact with infected pet prairie dogs who had been housed with Gambian pouched rats and dormice imported from Ghana. During this US outbreak, more than 70 cases of Mpox were reported.²

The Mpox virus has an incubation period of approximately 6 to 13 days but can range from 5 to 21 days. Following this, the invasion period of the infection occurs, often lasting between 0 to 5 days.

The symptoms of the invasion period include fever, intense headache, lymphadenopathy (swelling of the lymph nodes), back pain, myalgia (muscle aches), and intense asthenia (lack of energy) can occur. Specifically, the occurrence of lymphadenopathy is a distinctive feature of Mpox that distinguishes it from other diseases with similar symptoms, such as chickenpox, measles, or smallpox.²

The skin eruption phase of the infection often occurs within 1 to 3 days of the appearance of fever. Generally, the rash is more concentrated on the face (in 95% of cases) and palms of the hands and soles of the feet (in 75% of cases). However, rash can also occur in oral mucous membranes (in 70% of cases), genitalia (30%), and conjunctivae (20%), as well as the cornea.²

Mpox is usually a self-limited disease with symptoms that can last from 2 to 4 weeks. Commonly, severe cases of Mpox occur in children and are related to the extent of virus exposure, patient health status, and nature of complications. Further, the presence of underlying immune deficiencies can lead to worse health outcomes from the virus.²

Because vaccination against smallpox is protective against Mpox, people aged younger than 40 to 50 years (depending on the country) may be more susceptible to Mpox due to having never been vaccinated against smallpox. Additionally, known complications of Mpox can include secondary infections, bronchopneumonia, sepsis, encephalitis, and infection of the cornea with ensuing loss of vision. Further, the potential for asymptomatic infection to occur is currently unknown.²

The POC test is expected to begin shipping in the United States by the end of February.¹

Reference

1. Cepheid Receives Emergency Use Authorization from FDA for Xpert® Mpox. Sunnyvale, CA: Cepheid; Feb 14, 2023. Accessed Feb 15, 2023. https://prnmedia.prnewswire.com/news-releases/cepheid-receives-emergency-use-authorization-from-fda-for-xpert-mpox-301745998.html

2. WHO. Monkeypox. WHO website. May 19, 2022. Accessed Feb 15, 2023. https://www.who.int/news-room/fact-sheets/detail/monkeypox