Healthcare system strain and healthcare seeking behavior: the lingering impact of the COVID-19 pandemic on TB delayed diagnosis in Snohomish County, Washington

Background: The COVID-19 pandemic disrupted TB diagnosis due to overlapping symptoms, healthcare system strains, and changes in healthcare seeking behaviors. Our study aimed to examine factors contributing to delayed TB diagnosis during the post-acute phase of the pandemic in Snohomish County, Washington. Methods: A retrospective analysis was conducted using case data from January 1, 2022 to October 31, 2024. Fourteen of 85 incident TB cases (16%) met the study definition for delayed diagnosis, which included diagnosis four weeks or more after symptom onset and evidence of advanced disease, such as a chest cavity. Data were abstracted from medical records and public health surveillance systems. Results: Patient age raged from 20 to 83. Median time to diagnosis was six months (range 3–24 months), compared to one month (range 1–5 months) for patients who did not experience diagnosis delay. Two patients experienced delays of 11 or more months. Two patients died from TB related complications, one under the age of fifty. Three patients had confirmed COVID-19 within one year prior to TB diagnosis and five reported recent international or domestic travel. Seven patients had multiple healthcare visits prior to diagnosis and four indicated difficulties securing a healthcare appointment. Conclusions: Diagnostic delays in TB cases persist in the post-pandemic period with contributing factors including potential missed opportunities in clinical encounters. Strengthening provider awareness and improving diagnostic access remain critical to preventing TB transmission and severe disease outcomes.