Washington recorded 26,183 reported cases of chlamydia and 9,470 cases of gonorrhea in 2024, bringing the combined total to 35,653 cases. The figures come from the Washington State Department of Health’s 2024 STI surveillance data and represent reported cases rather than an estimate of every infection occurring in the state. Chlamydia remained the most frequently reported of the two infections, with a statewide rate of 325.8 cases per 100,000 residents. Gonorrhea had a rate of 117.8 cases per 100,000. Both declined from the previous year, when Washington reported 28,301 chlamydia cases and 10,181 gonorrhea cases. The state’s data also show that sexually transmitted infections remain a major public-health issue in Washington. The Department of Health notes that many STIs do not cause obvious symptoms, meaning people can have an infection and transmit it without realizing they are infected.

The Seattle region plays a major role in Washington’s STI statistics. In 2024, King County recorded 6,876 chlamydia cases and 4,447 gonorrhea cases. Combined, those two infections accounted for more than 11,000 reported cases in the county alone. Pierce County followed with 4,246 chlamydia cases and 1,458 gonorrhea cases, while Spokane County reported 2,123 chlamydia cases and 737 gonorrhea cases. Snohomish County recorded 1,937 chlamydia cases and 500 gonorrhea cases. The Washington Department of Health data show that nearly half of the state’s reported gonorrhea cases in 2024 came from King County. The county-level numbers highlight why sexual-health services, testing and prevention efforts remain particularly important in the Seattle metropolitan area.

Washington’s numbers come as the United States continues to face a substantial STI burden. The CDC reported more than 2.2 million combined cases of chlamydia, gonorrhea and syphilis in 2024. While that represented a 9% decline from 2023 and marked the third consecutive year of decreases, the national total remained 13% higher than it was a decade earlier. The widely cited “one in five” statistic comes from CDC prevalence research estimating that approximately 20% of people in the United States had an STI on any given day in 2018. The estimate included both diagnosed and undiagnosed infections, illustrating how reported case counts do not capture the full number of people living with an STI. The CDC has continued emphasizing testing and prevention because several infections can occur without noticeable symptoms. Chlamydia and gonorrhea are bacterial infections that can be treated, but untreated infections can lead to complications and can continue spreading to sexual partners.

Public-health officials stress that STI testing is an important part of prevention, particularly because symptoms are not always present. The CDC recommends routine screening based on factors such as age, sex, pregnancy status and individual risk, while Washington and King County provide additional local guidance and sexual-health resources. In King County, public-health guidance recommends regular syphilis testing for certain sexually active groups and identifies additional circumstances in which more frequent testing may be appropriate. Washington’s Department of Health also provides information about testing locations and prevention strategies.

The latest Washington numbers therefore tell a more complicated story than a simple rise in infections. Reported chlamydia and gonorrhea cases decreased from 2023 to 2024, but tens of thousands of infections were still documented statewide. With many STIs capable of producing few or no symptoms, health officials continue to emphasize testing, treatment, prevention and communication between sexual partners.