Time from arrival in Chile to tuberculosis diagnosis in migrants treated at primary care centers in two Metropolitan Region municipalities, Chile.

Introduction: In Chile, the number of migrants affected by tuberculosis has experienced a significant increase from 7.1% in 2014 to 29.7% in 2023, ranking as the first group at risk. The objective was to estimate the time to diagnosis of tuberculosis from arrival in Chile in a series of migrants undergoing treatment between January 2021 and March 2022.

Methods: We analyzed a cohort of migrants over 18 years of age with a diagnosis of tuberculosis treated in the communes of Recoleta and Independencia. Those who agreed to participate and signed the informed consent form were included. Cases with non-tuberculous mycobacteria and residents outside the Metropolitan Region were excluded. Sociodemographic, clinical, and arrival dates, as well as symptoms and diagnoses, were recorded. Proportional hazards models in STATA v.18 were used to analyze times according to independent variables. A p value < 0.05 was considered significant.

Results: The median time to diagnosis was 93.5 months, varying by subgroup. The recent migration subgroup without Chilean documentation had a hazard ratio of 13.1, which indicates that, at any time after arrival, these individuals have a 13-fold increased risk of tuberculosis diagnosis compared to the reference subgroup (traditional migration with Chilean identity documents). This hazard ratio is reduced by 2.4 times when these types of migrants have documentation from Chile (95% confidence interval: 1.2 to 4.5).

Conclusions: There is a wide range of time from arrival in Chile to the diagnosis of tuberculosis. Factors such as the type of migration and the type of identity document have an impact on the development of this disease. It is necessary to expedite the legal administrative process for migrants and implement timely screening policies, along with follow-up and improved access to healthcare, to reduce exposure and risk of tuberculosis.