Pierce County, WA – Public health officials have confirmed the detection of the clade I mpox virus, more commonly referred to as monkeypox, in Pierce County wastewater. The discovery, made on September 24, 2025, by the Washington State Department of Health in partnership with the University of Washington, has prompted a stronger focus on disease surveillance and community awareness.
Although no confirmed human cases have been identified in Pierce County so far, health leaders are treating the finding as an important reminder of how quickly viruses can emerge and spread. Officials say the current risk to the public remains low, but they are urging residents to stay informed and to seek medical attention if they develop symptoms consistent with mpox.
Why the Wastewater Discovery Matters
Wastewater testing has become one of the most reliable early warning systems for infectious diseases. By monitoring sewage, scientists can detect viral fragments shed by infected individuals—sometimes weeks before official case reports surface. This strategy gained traction during the COVID-19 pandemic and is now widely used to track viruses such as influenza, RSV, and mpox.
“This type of wastewater surveillance gives us a chance to act quickly before outbreaks occur,” explained Dr. James Miller, Health Officer for Tacoma-Pierce County Health Department. “It’s a tool that allows us to protect public health, assess risks, and inform the community when needed.”
The positive wastewater sample has led the Tacoma-Pierce County Health Department to strengthen its collaboration with both the Centers for Disease Control and Prevention (CDC) and the Washington State Department of Health. Expanded wastewater testing will now be conducted to determine whether the virus is present in additional locations or if this was an isolated detection.
Understanding Mpox: What Is Clade I?
Mpox, formerly known as monkeypox, is a rare viral disease that has been documented for decades in parts of Central and West Africa. It is caused by the monkeypox virus, a relative of the smallpox virus. In 2022, the World Health Organization (WHO) officially renamed monkeypox to mpox to reduce stigma and avoid racist or discriminatory language.
There are two primary strains of the virus:
- Clade I (Central African clade): Historically linked to more severe illness, higher hospitalization rates, and occasionally higher mortality.
- Clade II (West African clade): Associated with milder illness and was the main strain responsible for the global mpox outbreak in 2022–2023.
The detection in Pierce County involves clade I, which is considered more concerning due to its potential severity. However, experts emphasize that no local infections have been reported and the situation is under active monitoring.
Current Mpox Cases in the United States
The CDC reports that as of late September 2025, only six cases of clade I mpox have been confirmed across the U.S., all linked to international travelers returning from countries experiencing outbreaks.
Importantly, there is no evidence of sustained community transmission in the United States at this time. That means the virus is not currently spreading widely from person to person.
Still, the wastewater detection suggests at least one infected individual may have recently been in Pierce County, raising the importance of continued vigilance.
Symptoms to Watch For
Mpox symptoms can vary but often include:
- Flu-like symptoms: Fever, chills, fatigue, muscle aches, swollen lymph nodes.
- Rash: Starting as flat spots, then progressing to bumps, blisters, or ulcers. The rash may appear on the face, hands, feet, chest, genitals, or inside the mouth.
- Painful lesions: These may be mistaken for other conditions, such as chickenpox or sexually transmitted infections.
Most individuals recover within two to four weeks. However, severe cases can occur, particularly in:
- Children
- Pregnant individuals
- People with weakened immune systems
Health officials recommend that anyone experiencing a new or unexplained rash avoid skin-to-skin contact until evaluated by a healthcare provider.
How Mpox Spreads
The mpox virus spreads mainly through close physical contact, including:
- Skin-to-skin contact with an infected person’s rash or sores
- Intimate or sexual contact
- Contact with contaminated bedding, towels, or clothing
- Respiratory droplets during prolonged face-to-face interactions
Unlike COVID-19, mpox is not primarily airborne, and casual encounters such as walking past someone or brief conversations are unlikely to spread the virus.
Vaccine and Prevention Options
There is a vaccine available that provides protection against mpox, particularly for individuals considered at higher risk. This includes:
- People with known exposures to confirmed cases
- Certain healthcare workers and laboratory personnel
- Individuals in high-risk sexual networks
Residents in Pierce County who believe they may be at risk are encouraged to contact their healthcare provider or visit the Tacoma-Pierce County Health Department’s website for vaccination information and eligibility guidelines.
Preventive measures include:
- Avoiding close contact with anyone showing a suspicious rash
- Practicing safe sex, including the use of condoms and reducing partner networks
- Washing hands frequently with soap and water
- Using personal protective equipment (PPE) in healthcare or caregiving settings
Community Response and Public Reassurance
Local health officials emphasize that the discovery is not cause for panic. Instead, it reflects the strength of Pierce County’s public health infrastructure.
“Finding the virus in wastewater does not mean we have an outbreak,” said Dr. Miller. “It means our detection systems are working, and we’re taking proactive steps to keep the community safe.”
Community members have expressed a mix of concern and confidence. Some residents worry about potential risks to children in schools and public spaces, while others see the discovery as a reminder of the importance of vaccination and hygiene.
The Bigger Picture: Lessons From COVID-19
The COVID-19 pandemic taught health officials worldwide that early detection and transparent communication are essential to managing outbreaks. Wastewater surveillance—once a niche research method—has now become a frontline tool for protecting communities.
By combining wastewater testing with clinical data, health departments can:
- Identify viruses before widespread infections occur
- Allocate vaccines and resources strategically
- Inform hospitals and clinics about possible surges in cases
- Reassure the public with real-time information
Key Takeaways for Pierce County Residents
- Mpox clade I was detected in local wastewater, but no local cases have been reported.
- The current risk to the public is low, according to health officials.
- Wastewater surveillance is being expanded to monitor the situation.
- Residents should stay alert for symptoms and consult a doctor if they develop rashes or flu-like illness.
- A vaccine is available for individuals at higher risk.
Resources
- Tacoma-Pierce County Health Department: tpchd.org
- CDC Mpox Information: cdc.gov/mpox
- Washington State Department of Health: doh.wa.gov
