The North Carolina Department of Health and Human Services is asking people and providers to be on alert for mpox cases following the detection of mpox particles in multiple sewage samples found through routine wastewater testing. This year there have been two cases of mpox in North Carolina and the new wastewater detections were determined to be another type, clade I, not previously found in North Carolina. These detections indicate potential undiagnosed or unreported cases. At this time, the risk to the public remains low.
The mpox virus, formerly known as monkeypox, is primarily spread by prolonged close contact, typically skin-to-skin, often during sexual activity. There are two genetic types of the virus, known as clade I and clade II. The viral particles found in wastewater were determined to be clade I. To date, only four clade I cases have been reported in the U.S. Clade I mpox is responsible for a large outbreak in Central and Eastern Africa, which appears to be spreading mostly through heterosexual contact with some spread to household members, including children.
North Carolina’s detections were found in wastewater samples collected on March 25, March 28, and April 8 from a treatment plant in Greenville, NC. No clade I cases have been reported to date; however, these detections mean there was possibly at least one person with an undiagnosed or unreported clade I mpox infection present or traveling through the Greenville area around the time of these detections.
“The detection of clade I mpox virus in wastewater surveillance tells us the virus is potentially here in our state, even though no cases have been reported and confirmed,” said NC Health and Human Services Secretary Dev Sangvai. “We encourage health care providers to be on the lookout for mpox cases and we encourage people who are at higher risk to protect themselves by getting vaccinated.”
NCDHHS requests that all North Carolina health care providers consider mpox in patients with compatible symptoms and ask about any recent international travel. Providers who are treating patients with mpox infections should contact their local health department or the NCDHHS Division of Public Health’s 24/7 epidemiologist on-call number: 919-733-3419.
These recent results were found by the North Carolina Wastewater Monitoring Network, which launched in 2021 to better understand the spread of certain viruses in communities across North Carolina. This network is a collaboration between NCDHHS, the University of North Carolina at Chapel Hill, wastewater utilities and local health departments. Samples are collected routinely from 35 wastewater treatment plants across the state and tested for specific viruses, including SARS-CoV-2 (the virus that causes COVID-19), influenza, and respiratory syncytial virus (RSV). People with these viruses shed viral particles in their stool even if they don’t have symptoms. These virus particles are no longer infectious but can still be detected through lab testing.
