Site matters: Extrapulmonary tuberculosis localization patterns and clinical outcomes in the Netherlands, 1993-2022

Area of Science:

• Public Health
• Infectious Diseases
• Epidemiology

Background:

• Extrapulmonary tuberculosis (EPTB) represents a significant portion of tuberculosis cases in low-incidence countries.
• Limited comprehensive data exists on EPTB localization, contributing factors, and patient outcomes.
• Understanding these aspects is crucial for effective tuberculosis control.

Purpose of the Study:

• To investigate the anatomical distribution of EPTB.
• To identify demographic determinants associated with EPTB localization.
• To analyze clinical outcomes, including hospitalization and mortality, of EPTB.

Main Methods:

• Utilized national tuberculosis surveillance data from 1993-2022 in The Netherlands.
• Categorized patients into pulmonary TB (PTB), EPTB-only, and combined EPTB+PTB groups.
• Employed multinomial and multivariate regression analyses to assess determinants of localization and outcomes, with PTB as the reference.

Main Results:

• Out of 34,048 TB cases, 41.7% had EPTB-only and 10.2% had combined EPTB+PTB.
• Peripheral lymph node (30.8%) and pleural (25.8%) were the most common EPTB sites.
• Miliary and meningeal/CNS TB exhibited the worst outcomes; older age, HIV, diabetes, and immunosuppressants increased hospitalization and mortality risks.
• Treatment success rates for most EPTB localizations fell below WHO End TB targets.

Conclusions:

• EPTB presentation and outcomes in The Netherlands are influenced by age, sex, and country of birth.
• Disseminated and severe EPTB forms remain significant contributors to disease burden and mortality.
• Recognizing site-specific patterns is key for earlier diagnosis and improved EPTB management in low-incidence settings.