King County recorded a higher number of mpox cases in September than it has in the last three years, prompting public health officials to renew their push for vaccination.
At least 46 people were diagnosed with the infectious disease in King County in September, according to Public Health — Seattle & King County. While that count is much lower than it was during 2022, when 200 cases were reported that August alone, it’s a reminder the virus formerly known as monkeypox is still circulating locally and nationwide, said Dr. Tim Menza, co-director of the county’s sexual health clinic.
Seasonal peaks in the late summer have become fairly typical for mpox — which often causes a rash — and risk to the general public remains low, Menza said. Still, the 40-plus diagnoses this fall were peculiar, he said. They also were likely an undercount, Menza added.
“This is not necessarily a red alert,” Menza said in an interview. “It’s sort of like a ‘don't panic’ moment, but be aware. And there are ways one can protect themselves.”
Last September, King County recorded 21 cases; in September 2023, there were nine, according to the county’s mpox data dashboard. Since the outbreak began in 2022, health officials have confirmed about 730 King County cases, about 23 of which required hospitalization.
About 935 cases have been detected statewide since 2022. No deaths have been reported.
Menza said he’s not quite sure what was behind this year’s September surge, but guessed it was likely due to the large social events that happen during the summer.
The majority of mpox cases in King County are associated with sexual and intimate contact among men who have sex with men, and nonbinary and trans people who have sex with men, according to the local health department. The disease can affect anyone.
“Mpox is still here,” Menza said. “But vaccination and thinking about (behavior changes) are the big ways in which people can take this information and use it to protect themselves.”
The mpox vaccine, which involves two doses about 28 days apart, is highly effective at preventing severe cases of the disease and is widely available now, Menza said. People who are vaccinated and do become infected likely will experience milder symptoms.
The vaccine is available to people at higher risk for the illness, including those who were recently exposed to an infected individual. Others who are eligible for the vaccine include gay and bisexual people and other men who have sex with men; transgender, nonbinary or gender-diverse people who have sex with men; and people who engage in commercial or transactional sex.
Free vaccination is available at Public Health — Seattle & King County’s sexual health clinic at Harborview Medical Center. Kelley-Ross Pharmacy’s Capitol Hill and First Hill locations also offer vaccination, as well as other community health centers in Seattle.
In addition to vaccination, health officials said a temporary change in behaviors could also help lower risk of infection, including decreasing the number of sex partners; avoiding venues where there's direct skin-to-skin contact and where people wear minimal clothing; and being mindful of possible symptoms and talking to your partner about risks.
There are two types of mpox, clade I and clade II, both of which mainly spread through close physical contact with a person with mpox. In most cases, mpox spreads through sexual or intimate contact, but can also spread through direct contact with sores, body fluids or shared clothing, according to health officials. The virus does not spread through the air.
Infections can cause a painful skin rash and sometimes flu-like illness, though clade II infections — the type in King County and that's swept through the U.S. at low levels — are rarely fatal. Most people with clade II infections recover in two to four weeks, health officials said.
Clade I infections, however, are more severe. Few clade I infections have been reported outside eastern and central Africa, though last month health officials in California confirmed the more virulent form of mpox had been identified in three residents. It marked the first time clade I had been found in the U.S. among people who had no history of traveling overseas to high-risk areas, the Los Angeles Times reported.
A clade I infection has not been confirmed in Washington state. However, health officials identified signs of clade I in Pierce County wastewater in September. The finding indicates someone with a clade I infection might have been in Pierce County, but no case has been identified, according to the Tacoma-Pierce County Health Department.
© 2025 The Seattle Times. Visit www.seattletimes.com. Distributed by Tribune Content Agency, LLC.
