The Epidemiological Characteristics and its Associated Driving Factors of Tuberculosis Among Migrant Populations in Zhejiang Province

Background Population mobility exacerbates tuberculosis (TB) transmission risks. As a major immigration hub in China, Zhejiang Province has become a critical region for the importation of TB cases. This study aims to explore the epidemiological characteristics of TB in Zhejiang and identify the key driving factors associated with its transmission. Methods TB surveillance data in Zhejiang Province (2005–2023) was analyzed using joinpoint regression, age-period-cohort modeling, and spatial autocorrelation to examine incidence trends and disparities between migrant and local cases. The boosted regression trees model identified the driving factors of TB among migrant populations. Results Zhejiang Province witnessed an annual average TB incidence of 61.35 per 100,000, with 34.48% migrant cases. The incidence initially increased during 2005–2007 with an annual percent change (APC) of 2.76%, followed by sustained decline thereafter (APC = -4.12%), while migrant proportions increased until 2019 (APC = 5.83%) then sharply decreased during 2019–2023 (APC = -17.62%). TB incidence exhibited bimodal age effects (peaks aged 15–19 and 80–84 years) alongside birth cohort effects showing risk reduction in the post-1974 cohorts. The incidence hot spots transitioned from Hangzhou to Quzhou, while they persisted in Quzhou and Lishui for local cases, and contrasting shifted to Ningbo and Jiaxing for migrant cases. The gross regional product (GRP) per capita (56.82%, 95%CI: 56.19–57.44), tertiary industry proportion (8.98%, 95%CI: 8.66–9.27) and emigration index (7.38%, 95%CI: 7.16–7.67) were identified as the primary driving factors of TB among migrant populations. Conclusions Although a sustained decline in TB incidence was observed among the local population in Zhejiang, migrant proportions demonstrated steady growth. The incidence hot spots showed divergent patterns between migrant and local case. GRP per capita, tertiary industry proportion, and emigration index serve as primary driving factors for TB among migrant populations, which guide targeted strategies among origin-specific migrant populations to reduce TB transmission.