What’s new

All notable changes to the codebase are documented in this file.

Version 0.8.1 (2026-06-10)

• Fixed a UID/position confusion bug (#425) where several interventions identified agents by running np.where/np.flatnonzero over a starsim Arr’s compact, alive-only .values view and then treating the resulting positions as UIDs. Once any agents had died (so UIDs no longer matched compact positions), this silently selected the wrong agents. Affected HouseholdContactTracing.step, TPTHousehold.check_eligibility, TxDelivery._get_eligible, Migration._members_by_household_id, and HealthSeekingBehavior.step. All now use native starsim filtering (arr.auids[mask]) so positions map back to real UIDs.
• Added regression tests covering household contact tracing, treatment eligibility, care-seeking, and diagnostic administration after agent deaths.

Version 0.8.0 (2026-06-02)

• Added migration.py with a single Migration demographics class providing bidirectional, household-aware population turnover:
  • Immigration (new agents enter) and emigration (existing agents leave), each driven by an annual ss.freq rate; setting emigration_rate=0 gives immigration-only behavior
  • Optional maintain_population mode that tops up arrivals each step to hold the active (non-terminal) population near its starting size
  • Configurable immigrant age profiles via immigration_age_distribution bins or an age_data histogram, plus optional age-weighted emigrant selection via emigration_age_distribution
  • TB-state-aware imports: immigrants enter with a TB-state mix from tb_state_distribution, or a default derived from the TB module’s init_prev and progression parameters
  • Household integration with ss.HouseholdNet: immigrants are assigned to existing households (size-weighted) and wired into household edges, and emigrants are removed from their households
  • Per-step n_immigrants, n_emigrants, and net_migration results
• Removed the separate Immigration class in favor of the unified Migration class
• Removed the TBAcute model variant and its ACUTE state; only TB is supported now

Version 0.7.0 (2026-03-16)

• Added tbsim.Sim, a convenience wrapper around ss.Sim that auto-routes flat parameters between the sim and the TB module, provides TB-specific defaults (demographics, networks, disease), and supports a tb_model argument for selecting among TB model variants. Includes a demo() function for quick setup.
• Refactored all diagnostic and treatment interventions into a product/delivery architecture:
  • Added Dx diagnostic product class with DataFrame-based test definitions supporting state, age, and HIV stratification
  • Added built-in diagnostic products: Xpert, OralSwab, FujiLAM, CAD
  • Added DxDelivery intervention for delivering diagnostics with eligibility filtering, coverage, and false-negative retry logic
  • Added Tx treatment product class with drug-type-based efficacy
  • Added built-in treatment products: DOTS, DOTSImproved, FirstLine, SecondLine
  • Added TxDelivery intervention for delivering treatments with success/failure tracking and retry logic
  • Simplified drug_types.py to a single dictionary of drug parameters (previously ~600 lines of class hierarchy)
  • Removed old monolithic tb_diagnostic.py, tb_drug_types.py, and tb_treatment.py
• Removed TB_EMOD and renamed TB_LSHTM to TB; only TB and TBAcute are supported now
• Added HouseholdStats analyzer for tracking household size distributions, age-mixing matrices, and contact patterns over time when using ss.HouseholdNet. Includes visualization methods for household statistics, age-mixing heatmaps, and normalized contact matrices.
• Renamed tb_health_seeking.py to health_seeking.py and simplified the HealthSeekingBehavior class
• Moved immigration.py to an archive folder
• Added admin files (code_of_conduct.md, contributing.md, CHANGELOG.md)
• Updated starsim dependency to v3.2.1 for HouseholdNet support