Explosive diarrhea sounds…rough. Any rumbling in King County?

July 16, 2026.Reading time 8 minutes.

Una persona se agarra el estómago. Al fondo se ven un inodoro y un azulejo verde.

A national outbreak of Cyclospora—more commonly known by its main symptom, explosive diarrhea–continues to grow, but here in King County, we have not seen any unexpected increases in cyclosporiasis (the disease caused by Cyclospora) so far. We talked with Ann Shen, the lead for foodborne and enteric disease investigations for Public Health – Seattle & King County, about the local situation.

Public Health – Seattle & King County monitoring a fourth King County resident connected to cruise ship hantavirus outbreak

May 15, 2026.Reading time 4 minutes.

A line drawing of a cruise ship and an airplane Un dibujo lineal de un crucero y un avión.

Public Health – Seattle & King County was notified on 5/14/26 of an additional King County resident that was on the same plane as an ill passenger from the MV Hondius cruise ship announced on Tuesday, 5/12/26. The King County resident is considered at low risk for infection because they were not seated near the ill passenger. This resident is asymptomatic and monitoring for symptoms.

Three King County residents connected to international cruise ship in public health monitoring for hantavirus

May 12, 2026.Reading time 4 minutes.

Ilustración de un crucero navegando frente a un paisaje montañoso.

Public Health – Seattle & King County has been notified about three King County residents who were potentially exposed to hantavirus linked to the MV Hondius cruise ship. All three are asymptomatic and monitoring for symptoms, in coordination with public health officials. There are no cases of hantavirus in King County at this time.

Measles case identified in a King County infant

April 10, 2026.Reading time 6 minutes.

Public Health – Seattle & King County is informing the community of a confirmed measles case in a King County infant who may have exposed others to the measles virus.

Legionella: How this lesser-known bacteria in water systems can impact your health

April 2, 2026.Reading time 9 minutes.

Stainless steel showerhead spraying water downward. Blue tile in the background.

In 2025, there were 33 cases of Legionella infections among King County residents compared to 8 cases in 2005. But there is good news: Legionnaires’ disease is preventable!

Two measles cases identified in King County connected to international travel

April 1, 2026.Reading time 6 minutes.

Public Health – Seattle & King County was notified on March 30, 2026, of measles cases in two adults who live in King County. The two individuals traveled together internationally where they were likely exposed to measles. Before they were diagnosed with measles, the two individuals visited multiple locations in Seattle, Kirkland and Bellevue while infectious.