Public Health – Seattle & King County is managing a confirmed case of active tuberculosis at Aegis Living, a retirement community in Issaquah, prompting health officials to recommend TB evaluations for 38 people who may have been exposed to the infectious resident.
The health department is working closely with the senior living facility to assess the scope of potential TB exposure amongst residents and staff whilst coordinating the medical evaluation process for those who may have come into contact with the infected individual during the contagious period.
Health officials are providing guidance and information to both staff members and residents as the facility navigates the response protocols, emphasising that tuberculosis, whilst serious, spreads far less readily than many people assume based on their familiarity with more contagious respiratory illnesses.
Public Health indicated that TB, an infectious disease caused by airborne bacteria, is notably more difficult to transmit than illnesses like COVID-19, the common cold, or influenza. Infection typically requires prolonged exposure in confined indoor spaces rather than the brief casual contact sufficient for many viral respiratory infections. Even within households where family members share living spaces continuously, only approximately one-third of close contacts become infected when exposed to a contagious individual, Public Health stated, providing context that should temper alarm amongst facility residents and their families.
As a precautionary measure, Public Health recommended that 38 people associated with Aegis Living undergo TB evaluation, a process involving medical risk assessment and TB testing. The facility will directly contact those needing evaluation based on their exposure patterns and risk factors. All staff members, residents, and their families are being informed about the situation this week regardless of their individual exposure level, ensuring transparent communication even for those at minimal or no risk.
If any individuals are found to have latent TB infection following evaluation, Public Health will facilitate treatment to eliminate the TB bacteria and prevent progression to active TB disease. Latent TB infection, which is not contagious and produces no symptoms, can be successfully treated within three to four months using antibiotics. The individual with active TB is currently receiving treatment from Public Health, which typically involves a six to nine-month course of multiple antibiotics taken in combination to ensure the bacteria are completely eradicated.
The distinction between active TB disease and latent TB infection represents a crucial concept for understanding risk and treatment protocols. Active TB disease can be transmitted to others through respiratory droplets when infected individuals cough, sneeze, speak, or sing, making isolation and treatment urgent public health priorities. Latent TB infection, by contrast, cannot be spread to others because the bacteria remain dormant within the body without causing symptoms or creating infectious respiratory secretions.
In King County, approximately 100,000 people carry latent TB infection, a substantial population representing roughly 4% of the county’s 2.3 million residents. Of those with latent infection, about 5% will develop active TB disease within two years of initial infection, and another 5% will progress to active disease at some point over their remaining lifetime. These progression rates explain why public health authorities prioritise identifying and treating latent infections preventively rather than waiting for active disease to develop, as early intervention with shorter treatment courses prevents both individual suffering and community transmission.
TB primarily affects the lungs, causing the classic symptoms of persistent cough, chest pain, and coughing up blood or sputum, but the bacteria can also spread to other parts of the body including the kidneys, spine, and brain, creating diverse clinical presentations that sometimes delay diagnosis. The pulmonary focus explains TB’s respiratory transmission pattern and why prolonged indoor exposure creates highest risk, as the bacteria travel in tiny airborne particles that remain suspended in indoor air for hours after an infected person coughs or speaks.
In 2024, King County reported 110 new cases of TB disease, averaging approximately two diagnoses per week. This incidence rate, whilst modest compared to historical levels before effective treatment became available in the mid-20th century, demonstrates that TB remains an ongoing public health concern requiring surveillance, rapid case identification, contact tracing, and treatment to prevent transmission chains from establishing within communities.
The senior living facility setting creates particular vulnerability to TB transmission because residents live in congregate environments with shared dining spaces, common areas, and frequent social interactions that create opportunities for prolonged indoor exposure. Additionally, older adults experience age-related immune system weakening that increases both their susceptibility to infection when exposed and their risk of progressing from latent to active TB if they carry dormant bacteria.
