Multilingual PHI detection — support Spanish, French, German patient data

[sarvanithin]

Overview

The current RegexPHIEngine is English-only. Clinical AI systems in Europe and Latin America handle patient data in Spanish, French, German, and Portuguese. PHI patterns differ by locale (e.g., Spanish DNI vs US SSN, European date formats DD/MM/YYYY).

What to build

• medguard/guardrails/phi_i18n.py — locale-specific PHI patterns
  • Spanish: DNI \d{8}[A-Z], NIE [XYZ]\d{7}[A-Z], date \d{2}/\d{2}/\d{4}
  • French: INSEE (SS) number, RPPS doctor ID
  • German: Krankenversichertennummer (KVNR)
• LocalePHIEngine(locale="es") — wraps RegexPHIEngine with locale patterns
• Add locale: str = "en" to PHIConfig

Files to create/modify

• medguard/guardrails/phi_i18n.py — locale pattern definitions
• medguard/guardrails/phi.py — LocalePHIEngine class
• medguard/config.py — add locale to PHIConfig
• tests/test_phi.py — parametrized tests for each locale

Acceptance criteria

• Spanish DNI 12345678Z detected and redacted
• French INSEE 1 84 12 76 451 099 52 detected
• No false positives on clean text in each locale
• PHIConfig(locale="es") selects Spanish patterns
• All existing English tests still pass

Resources

• Spanish DNI format: https://es.wikipedia.org/wiki/Documento_nacional_de_identidad_(España)
• French INSEE: https://fr.wikipedia.org/wiki/Numéro_de_sécurité_sociale_en_France