Pathogen and host determinants of extrapulmonary tuberculosis among 1035 patients in Frankfurt am Main, Germany, 2008-2023.

Objectives: Extrapulmonary tuberculosis (EPTB) presents with nonspecific symptoms which can pose a significant diagnostic challenge. Various factors, including age, sex, and HIV status, have been associated with an increased risk of developing EPTB. However, the influence of the lineage of the infecting Mycobacterium tuberculosis complex (Mtbc) strain remains controversial.

Methods: Between 2008 and 2023, comprehensive clinical data from 1035 cases, along with whole genome sequencing (WGS) data of the respective Mtbc strains have been collected. To examine the association between Mtbc lineage and EPTB, we calculated crude and adjusted odds ratios (OR) using logistic regression and performed propensity score matching with a subset of the cohort.

Results: Of the 1035 patients, 272 had exclusively extrapulmonary disease and 138 had both pulmonary and extrapulmonary disease. Patients infected with a lineage 1 strain had the highest odds of developing EPTB in the univariate analysis (OR: 3.30, 95% CI: 1.97-5.49). However, Mtbc lineage was not a significant predictor in the multivariable model, while the odds of developing extrapulmonary disease were higher among patients born in the South-East Asian region (adjusted OR: 6.00, 95% CI: 3.41-10.69) and the Eastern Mediterranean Region (adjusted OR: 5.95, 95% CI: 3.61-9.96) compared to those born in the European region. Further, female sex and age were significant positive predictors for EPTB.

Conclusions: Our results demonstrate that host factors, such as geographic origin, age and sex are stronger predictors for EPTB than infection with a Mtbc strain of a particular lineage. Further investigation of this host-pathogen interaction is needed.