What’s new

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

Version 1.6.1 (2026-09-04)

• Age and sex stratification of disease results is now optional. Every BaseSTI subclass (Chlamydia, Gonorrhea, Trichomoniasis, Syphilis, HIV, BV) now accepts age_bins and sex_keys; passing None for either skips the corresponding stratified results, leaving the whole-population ones untouched and numerically identical. Defaults are unchanged, so existing models are unaffected. Disabling both takes a gonorrhea module from 205 results to 29, which matters for large multi-sims and low-memory runs. sti.default_age_bins and sti.default_sex_keys are exported for building custom stratifications. SEIS also gains age_range as a constructor argument, previously hardcoded to [15, 65]. (#592)

Version 1.6.0 (2026-08-28)

This version requires starsim>=3.6.0, and the bugs found while migrating to it change simulated epidemiology and reported results enough that chlamydia, gonorrhea, trichomoniasis and syphilis calibrations have all changed.

• Gonorrhea and trichomoniasis over-reported incidence by ~1.9x. BaseSTI.update_results counted new infections as ti_infected == ti, but SEIS writes ti_infected twice: set_exposure() schedules the exposed->infectious time, then step_state() overwrites it with the realized one. With dur_exp = 0 (the default for both diseases) those fall on different timesteps, so each infection was counted twice. Incidence is now counted at acquisition via ti_exposed, which is written exactly once and never rewritten, so the test is correct by construction; ti_exposed moved up to BaseSTI, and ti_infected again means only “became infectious”. Against a direct count of set_prognoses() calls, the two diseases reported 1.93x and 1.86x the true infections and now report 1.00x. All incidence-derived results were affected; transmission dynamics were not. Regression: both were calibrated to roughly double the true incidence. Chlamydia’s totals are unchanged but shift one timestep earlier.
• SEIS prevalence and n_infected excluded the latent period. SEIS used infected for the I compartment alone, so n_infected, prevalence and every age/sex-stratified variant silently dropped exposed agents. Following Starsim v3.6.0’s ss.SEIR, infectious is now the literal I compartment and infected is derived as E plus I; ti_infected is replaced by ti_infectious (time of becoming infectious), with ti_exposed remaining the time of acquisition. Transmission still depends on infectious alone, so no dynamics change: over a 5000-agent/20-year sim the infection counts are identical, but reported prevalence rises 7.0% (ct), 14.6% (ng) and 7.6% (tv) relative. A new n_infectious result gives the transmitting compartment on its own. Migration: disease.ti_infected on ct/ng/tv no longer exists (use ti_infectious or ti_exposed), and disease.infected now includes exposed agents; SEIS.treatable was already E plus I, so it is now just infected and the override is gone. Chlamydia’s bacterial-load update and the HIV coinfection connectors were switched to infectious, preserving their previous behaviour. ANCTest keys its detection off infected, so if it is pointed at an SEIS disease (disease_names=['ct']; the auto-detected defaults are HIV and syphilis) it now detects exposed agents too, matching the treatable pathway the other test interventions use.
• The syphilis latent transmissibility half-life had no effect. set_latent_trans() computed np.exp(-np.log(2)/pars.rel_trans_latent_half_life * dur_latent); under starsim < 3.6.0 the ufunc discarded the rate’s denominator, so every half-life gave identical decay and latent rel_trans halved every timestep regardless. The half-life is now converted to timesteps with to_dt(), making decay 12x slower at monthly dt. Regression: over a 5000-agent/20-year sim, endpoint prevalence rose from 0.142 to 0.202 and cumulative infections from 493 to 674 (mean of 3 seeds); syphilis calibrations need redoing.
• Trichomoniasis “persistent” female infections lasted 8.3 years instead of 100. set_duration added pars.dur_persist (ss.years(100)) to a timestep index without converting to the module’s dt, so the bare magnitude was used (100 months at monthly dt). Realized persistence is now 1200 timesteps rather than 100. Regression: female prevalence rises substantially in runs longer than ~8 years.
• Syphilis stillbirths/miscarriages could be misclassified as live births. Syphilis.set_congenital scheduled miscarriage/stillbirth outcomes at the same timestep as ti_delivery, but Pregnancy.process_prenatal_deaths only classifies a death as a fetal loss when age<0, which flips to 0 exactly at ti_delivery; these babies were counted as live births by the Pregnancy module while syph’s own new_stillborns/new_congenital_deaths still counted them as fetal losses. Fetal-loss outcomes now fire one timestep before ti_delivery, matching the equivalent fix already applied to starsim’s generic congenital framework in v3.6.0. Also fixed ti_miscarriage, which was assigned an outcome but never fired a death or was counted in any result — invisible under default parameters since miscarriage probability is 0 in all birth_outcomes distributions, but live for any custom parameterization with nonzero miscarriage probability. Adds a new_miscarriages result, now included in new_congenital_deaths. (#588, #590)

Version 1.5.11 (2026-08-24)

Breaking changes

• On-ART mortality is now nonzero by default. Previously, agents on ART had zero HIV-specific mortality; on-ART death now follows an age/sex/CD4/adherence-adjusted rate anchored to (and always ≤) the off-ART CD4-based hazard. Models calibrated against 1.5.10 or earlier will need recalibration. (#556, #561)
• Circumcision state moved from VMMC to HIV. VMMC.circumcised/VMMC.pars.eff_circ no longer exist — use HIV.circumcise()/HIVPars.eff_circ/eff_circ_traditional. Any VMMC subclass reading those attributes directly will break. (#576)
• HIV.never_art renamed to art_naive, and ART status is now one of four mutually-exclusive states: art_naive, on_effective_art, on_nonsuppressive_art, art_discontinued. (#556)

Diseases

• HIV: new ART adherence model. p_effective_art (default 1.0) determines what fraction of newly-initiated agents achieve viral suppression (on_effective_art) vs. non-suppressive ART (on_nonsuppressive_art); adherence status now affects both mortality (rel_art_mortality_effective/unsupp_m/unsupp_f, art_death_age) and transmission (effective_art_efficacy, nonsupp_art_efficacy, ramping in over time_to_art_efficacy). On-ART mortality is anchored to the off-ART CD4-based hazard so it can never exceed it at the same CD4 count — now enforced by an assertion at init rather than a docstring note. (#556, #561, #583)
• HIV: rel_death_f (the female mortality multiplier) now applies off-ART as well as on-ART; previously it only applied on ART, with no documented reason for the asymmetry. (#583)
• HIV: circumcision (circumcised/circ_traditional/eff_circ/eff_circ_traditional) moved from VMMC onto HIV so multiple circumcision pathways can share the same state. VMMC gains an independent traditional (non-program) circumcision pathway (traditional_prob, traditional_age) alongside program VMMC — both write through the same HIV.circumcise() sink, so someone circumcised by either pathway is automatically excluded from the other. (#576)
• Syphilis: fix a reactivation-from-latent bug where the previous fix for “reactivation never happens” caused the opposite failure — every latent agent flipped back to secondary the timestep after entering latency, regardless of the reactivation draw, collapsing latency to a ~1-timestep blip and effectively disabling tertiary progression. (#569)
• Removed the dead post_art state: it was declared and cleared on infection-clear, but nothing ever set it True (superseded by art_discontinued, which everything else already reads); hiv_n_post_art was silently always 0.

Interventions

• ART gains vls_coverage: the fraction of newly-initiated agents achieving viral suppression, accepting the same scalar / time-varying / age-sex-stratified DataFrame formats as coverage (replaces the scalar-only p_effective_art kwarg). (#577)
• Prep (PrEP) reimplemented as a stock-target intervention parameterized by prep_eff/prep_dur/prep_adh. State (prep_naive/on_prep/prep_discontinued/etc.) now lives on HIV, so multiple Prep instances (e.g. oral + long-acting) share enrollment history and are mutually exclusive. (#581)

Bug fixes

• vls_coverage: a stratum missing from a stratified DataFrame silently defaulted to 0% suppression instead of the documented 100%; scalar/single-column inputs outside [0, 1] weren’t validated; the legacy p_effective_art kwarg could silently override vls_coverage with no warning. (#577)
• Prep: age-only stratified coverage (no Gender column) defaulted to males only, silently enrolling nobody for Prep’s typical (female) target populations. (#581)
• The ART transmission-efficacy ramp divided by a raw month count instead of converting to timesteps via dt — only correct at the default monthly resolution. At other dt (e.g. weekly), the ramp could overshoot and drive rel_trans negative. (#583)

Documentation

• Rewrote the HIV user guide’s “On-ART mortality” and “On-ART transmission” sections for the new adherence model, including a worked derivation of nonsupp_art_efficacy (a Quinn/Rakai viral-load hazard-ratio calculation) and updating effective_art_efficacy to 0.99 (“U=U” — PARTNER/PARTNER2/Opposites Attract found zero linked transmissions from virally suppressed partners across thousands of couple-years). (#582, #583)
• Document PrEP’s new parameterization and multi-product usage in the interventions user guide. (#581)

Tests

• Add regression tests for the on-ART mortality invariant, the efficacy-ramp dt bug, rel_death_f applying off-ART, vls_coverage’s missing-stratum default and value validation, and Prep’s age-only stratified coverage. (#577, #581, #583)

Version 1.5.10 (2026-07-24)

Bug fixes

• HIV.stop_art now actually sets post_art=True. The post_art BoolState was defined but only ever cleared to False in clear_infection, so downstream cascade-stage attribution (e.g. transmission-source-by-ART-status analyzers) couldn’t distinguish “never on ART” from “on ART, now interrupted”. start_art also clears post_art when re-enrolling a previously-interrupted agent. (#544, #541)
• STITest/SyphTest no longer crash with the default eligibility=None. get_testers treated None as a non-callable UID list instead of falling back to check_eligibility() (which already handles None → everyone), so any test intervention without an explicit eligibility function crashed on its first step. (#537, #562)
• Syphilis: fix new_nnds / new_stillborns (and derived new_congenital_deaths / cum_congenital_deaths) always reading 0 — step_state cleared ti_nnd / ti_stillborn to NaN before update_results could match them against the current timestep. Counts are now stashed before clearing, mirroring the existing _new_congenital_count pattern. (#560)
• ANCTest: fixed a crash under current starsim (ss.dur(1, 'month') → 'months') and a bug where active_diseases was resolved after super().init_pre(sim) had already called init_results(), so per-disease results (n_<disease>_positive) were never created. ANCTest had zero test coverage before this. (#324, #546)

Diseases

• Syphilis: rebalance the mat_active (primary/secondary maternal infection) birth-outcome distribution — miscarriage probability raised (0.10→0.25 early, 0.20→0.25 late) and neonatal death lowered (0.25→0.05) — to better match Gomez 2013 / Cooper 2016, which put most adverse outcomes earlier in pregnancy rather than post-partum. (#543, #541)
• Syphilis: expose per-fetus mtct_from_{mat_active,early,late} flags recording the mother’s disease stage at the moment of mother-to-child transmission, so downstream analyzers can bucket congenital outcomes by maternal stage without reconstructing mother/fetus linkage. (#548)

Demographics

• sti.Migration gains rel_migration (default 1), analogous to ss.Deaths.rel_death: scales both immigration and emigration each timestep. (#542, #545)

Documentation

• Fill in the “Antenatal and infant screening (PMTCT)” stub in the interventions user guide (ANC → ART → newborn-test cascade, maternal_care_scale cross-reference) and add a new gallery example, pmtct_scenario.qmd, comparing MTCT infections and pregnant-women diagnosis rates with/without ANC testing. (#324, #546)
• Document the risk_group/sex/sw-stratified DataFrame format accepted by SyphTest.test_prob_data. (#537, #562)

Tests

• Add tests/test_anc_test.py (smoke test, immediate-ART-scheduling invariant, newborn-test scheduling) and tests/test_sti_interventions.py (default-eligibility regression, stratified test_prob_data) — both interventions had zero coverage before this.
• Add tests/test_demographics.py covering rel_migration.

Version 1.5.9 (2026-07-13)

Bug fixes

• VMMC now hits its coverage as a prevalence (stock) target, not a per-step hazard. The 1.5.6 rewrite computed the per-timestep target over the uncircumcised pool and only in aggregate, so coverage behaved as a per-step uptake rate on the remaining-uncircumcised men: realised circumcision coverage ratcheted toward ~100% regardless of the target, and the age/sex stratification in the input data was ignored (all ages converged to the same level). VMMC.step() now tops up to coverage × (all eligible males) per (age, sex) stratum each step — the denominator includes already-circumcised men, matching cross-sectional survey definitions — and never removes (circumcision is irreversible). Realised coverage converges to the target and preserves the input age gradient. Models calibrated against 1.5.6–1.5.8 VMMC behaviour will need recalibration. (#535)
• HIV.set_prognoses now calls super(), fixing ss.infection_log() for HIV. HIV overrode Disease.set_prognoses() entirely for its natural-history setup and never called super(), so the infection log’s append hook never fired for HIV specifically (other diseases such as SEIS-based Gonorrhea were unaffected). Infection log entries for a 1000-agent HIV sim went from 0 to 259 after the fix, restoring source/target transmission tracking (e.g. attributing onward transmission to a source subgroup). (#536)
• GonorrheaTreatment.set_treat_eff now defends against NaN rel_treat: a small fraction of agents allocated but inactive at sim.init keep an uninitialized slot and read back as NaN when reactivated, which previously propagated to treat_eff and made those agents always fail treatment. NaN entries are now replaced with the declared default (1) before computing treat_eff. (#528)
• art_coverage analyzer plotting no longer produces two identical plots. (#530)

Tests

• Add test_vmmc_hits_target, asserting realised male circumcision prevalence converges to the coverage target. The existing test_vmmc_specs only checked that some circumcisions occurred, which is why the overshoot regression went undetected.
• Regenerate baseline.yaml / benchmark.yaml for starsim 3.5.1 (CRN hash-based random number generation changed the exact values of agent-indexed draws; results are statistically equivalent per starsim’s changelog). test_shorter_sw now uses rand_seed=2 — rand_seed=1 drew zero FSW-sourced HIV transmissions in both arms from the small FSW pool (~9/2000 agents) under the new CRN scheme, making the comparison degenerate.

Diseases

• Syphilis: clear early / late sub-flags when a mother exits the latent state (reactivation to secondary, or progression to tertiary). Previously these BoolStates persisted, so set_congenital’s outcome loop for state in ['mat_active', 'early', 'late'] would overwrite the correct mat_active draw with the (now-stale) early / late table draw — biasing MTCT outcomes for reactivating mothers toward normal (the late table is 80% normal vs mat_active’s 25%). Empirical impact in a hot-seed ANC screening sim: untreated-secondary MTCTs read 67% normal instead of the expected 25%. (#538)

Diseases

• Syphilis: fix new_nnds and new_stillborns (and the derived new_congenital_deaths / cum_congenital_deaths) always reading 0. step_state cleared ti_nnd / ti_stillborn to nan when scheduling the deaths, so the == ti check in update_results (which runs after) never matched. Mirror the existing _new_congenital_count pattern: stash the counts before clearing and read from the stash in update_results.

Version 1.5.8 (2026-06-25)

Logistics

• Add a stisim.logistics package for supply-constrained interventions: Product (cost, delivery mode, time-varying efficacy), Supply/Supplies (quantities and accrued cost), ProductCategory/DeliveryMode enums, and the abstract SuppliedIntervention base that distributes a product across eligible agents subject to available supply. (#492)

Interventions

• PartnerNotification: optional edge-type / partner-sex stratification. step() now walks current-channel edges preserving edge-type info and exposes current_partner_edges ({partner_uid: [edge_type_int, ...]}) to callables on p_notify_current.p / p_attends_current.p. New sti.pn_rates(rates) helper builds such a callable from a dict spec — either {'stable': 0.20, 'casual': 0.10} or per-partner-sex {'stable': {'f': 0.80, 'm': 0.50}, ...}. Per-edge probabilities for multiply-reached partners are summed and capped at 1. Scalar p_notify_current / p_attends_current Bernoullis are unchanged (backward compatible). (#505)

Documentation

• New user-guide pages for analyzers (docs/user_guide/analyzers.md) and care-seeking (docs/user_guide/care_seeking.md).
• Expand the interventions user guide with syndromic management, antenatal/infant (PMTCT) screening, partner notification, and pregnancy-driven risk reduction.
• List all gallery examples in the sidebar; fix syphilis API drift that broke the docs build.

Tests

• Add pn_rates stratification tests.
• Regenerate baseline.yaml / benchmark.yaml for starsim 3.4.0 (n_female).

Version 1.5.7 (2026-06-15)

Diseases

• Syphilis: add treponemal (trep) and non-treponemal (nontrep) serology states with seroconversion/reversion dynamics (window period, ~80% lifelong trep persistence, non-trep titre decline + post-treatment reversion). New trep_prevalence/nontrep_prevalence results (overall, by sex, by age×sex) plus sexually_transmissible/symptomatic/primary stage prevalences. Consolidated the duplicate active property into symptomatic (removed active_prevalence and the *_prevalence_15_64 results). Prevalence denominator age band is now configurable via age_range, exposed as a BaseSTI constructor argument. (#500)

Networks

• Add fsw_mf_conc_mult on StructuredSexual to scale FSW non-sex-work concurrency (values <1 = fewer non-commercial partners). MFNetwork.set_concurrency is now negative-binomial-aware: it reparameterizes the target mean correctly instead of silently no-opping when concurrency_dist is ss.nbinom. (#500)
• Fix the three MSM networks (AgeMatchedMSM, AgeApproxMSM, MSMScaleFreeNetwork): all now honour a participation filter and no longer crash at init. The participation parameter is renamed msm_share → p_msm. (#502)

Interventions

• SyndromicManagement and SymptomaticTesting now take disease names (e.g. diseases=['ng', 'ct']) rather than module objects, resolved against sim.diseases at init. Objects passed at construction were deep-copied into orphans the sim never stepped, giving stale state and dropped result-writes. (#503)

Analyzers

• Add sti.PartnershipFormationAnalyzer. Networks now record the timestep each relationship ends (None if still active at sim end), enabling efficient post-run partnership analysis from a shared results store. (#504)

Results

• Remove the unimplemented partners_12 / n_partners_12m references. (#473, #507)

Version 1.5.6 (2026-06-02)

Networks

• Breaking — default behaviour change. Split stisim/networks.py into a stisim/networks/ sub-package (base.py, mf.py, fsw.py, msm.py, layered_networks.py, matchers.py). Add a match_method string parameter on MFNetwork, dispatched through a MATCHERS registry of pair-formation algorithms (accepts string or callable). The previous default (sort_bisect) collapsed the M-F age gap to ~0 because it didn’t honour age_diff_pars. Eight matchers ship in the registry. Removes stisim/pfa_variants.py and the seven MFNetwork_* subclasses. (#472)
• New closest_age_tapered_seeking matcher, now the default. Orders females by desired_age = age + normal(target_gap, stddev) (drawn each step for under-partnered females) and males by age; uses batch-binary-search to find each female’s closest available match, with a taper that reduces seeking for older females to bring mean age gaps into data alignment. Realised mean age gap is now within <5% of target (was negatively biased and growing); target stddev preserved. Downstream calibrated models will need recalibration: HIV prevalence shifts ~18% in Zimbabwe and ~59% in Eswatini at default settings. (#477)
• Add sti.MSMScaleFreeNetwork: a preferential-attachment MSM sexual network with continuous-time formation/Markovian deletion (Whittles-2019 S2 kernel). Restricted to post-debut males in this first port; subclass hooks (_get_pool, _mix_node_arrays, _mix_weights_row) let you plug in age-/risk-/λ-weighted variants. Documented as not branching-stable under starsim CRN (global weighted-categorical sampling over a pair catalog). Ported from starsim_x/BespokeNet, contributed by Stephen Attwood (Oxford). (#488)

Interventions

• Add sti.PregnancyRiskReduction: during pregnancy, optionally clears FSW status (fsw_redux), drops high-risk-group membership to default_risk_group (high_risk_redux), and/or zeros concurrency (concurrency_redux). Ported from syph_dx_zim. (#482, #484)

Documentation

• New ART state diagram in the docs illustrating how ART intersects the HIV mortality cascade. (#471)

Tests

• Regenerate tests/baseline.yaml for the new default matcher.
• Add tests/update_baseline script (mirroring hpvsim’s pattern) to regenerate both baseline.yaml and benchmark.yaml in one command.

Version 1.5.5 (2026-05-15)

Sim / parameter routing

• Add sti.route_pars utility (in stisim/utils.py) that auto-discovers par categories (sim, sti, nw, dem) from the par-class registry and routes flat kwargs accordingly. Cross-category clashes broadcast to all matches with a printed note; unknown keys raise when strict=True. sti.Sim.separate_pars now delegates to it and shrinks from ~95 to ~30 lines. (#451, #452)
• Auto-add coinfection connectors when diseases=[...] is supplied without an explicit connectors=. Lookup tries sti.<d1>_<d2> then sti.<d2>_<d1>; pairs with no registered class are silently skipped. Replaces the previous NotImplementedError stub. (#442, #453)
• Route flat connector pars (e.g. rel_sus_hiv_syph=3.5) through to the matching connector instance. (#442, #453)

Interventions

• Replace PartnerNotification with a PriorPartners-based implementation. Two channels (current sexual network, optional prior-partner recall network) each with separate notification × attendance probabilities. Tracks notifications and attendance per-channel. The previous transmission-graph-based version is removed. New gallery example docs/examples/partner_notification.qmd. (#457)
• Add dur_dx2tx parameter to HIVTest (default ss.constant(0)) for the delay between HIV diagnosis and ART start. HIVTest now schedules hiv.ti_art = ti + delay on positive results; ART becomes passive and starts agents whose ti_art == ti & ~on_art. ANCTest and initially-diagnosed cases schedule with no delay (backward compatible). (#398, #464)
• Fix ART stratified coverage to allocate per-(age, sex) stratum independently. Previously, stratified coverage data was parsed correctly but then collapsed to a single aggregate target before correction, washing out the age/sex differentials in the input. New compute_stratum_targets helper in interventions/utils.py. (#463)

HIV

• new_agents_on_art result now gates on on_art (since ti_art may also hold a scheduled future start). (#464)

Documentation

• New gallery example docs/examples/vmmc_costing.qmd: attach unit costs to sim.results, discount, and compute an ICER for VMMC vs no-VMMC, framed as a quick STIsim analog of Bansi-Matharu et al., Lancet Global Health 2023;11(2):e244–e255. (#455, #465)

Version 1.5.4 (2026-05-04)

Networks

• Split StructuredSexual into reusable MFNetwork (heterosexual) and SWNetwork (sex-work) networks built on a new BaseNetwork. StructuredSexual is preserved as the combined default. (#307, #445)
• Window sex-work participation by per-agent age_sw_start + dur_sw instead of lifetime; fsw / client / age_sw_stop are now derived properties. (#307, #445)
• Add condom_smoothness parameter forwarded to sc.smoothinterp for time-varying condom data. (#445)
• Replace shared debut / debut_pars_f / debut_pars_m with per-sex debut_f / debut_m distributions; supports scalar shortcuts, full ss.Dist instances, and callables. (#397, #420, #423)

Interventions

• Add SyndromicManagement to core stisim, consolidating duplicated implementations from anc_sti_screening and stisim_vddx_zim. cervical_diseases parameter generalises the cervical-symptom check. (#369, #443)
• Add ANCTest for single-visit ANC screening (auto-detects HIV + syphilis; per-disease sensitivity; routes to treatment maps). Raises if disease names are mistyped. (#370, #444)
• Add InfantHIVTest for newborn/infant testing scheduled by ANCTest or by HIVTest via the maternal network. (#370, #444)
• Decouple Prep eligibility from clinical filters: user-supplied eligibility= callables now express targeting only; ~hiv.infected and ~on_prep are applied unconditionally. (#330, #441)
• Refactor Prep legacy years= handling: pop from kwargs before update_pars instead of reading back from self.pars. (#444)

HIV

• Update acute HIV defaults to Bellan 2015 central estimates: rel_trans_acute=N(5.3, 0.5), dur_acute=LogNorm(1.7 mo, 1 mo). EHM drops from 15 to ~7.3. (#396, #426)
• Add rel_sus_age: list of (age_lo, age_hi, sex, multiplier) tuples for age/sex-stratified susceptibility. Default None preserves existing behaviour. (#395, #427)
• Remove BaseSTI.infect() override; inherits parent ss.Infection.infect() for free mixing-pool compatibility. (#412, #421, #422)

Sim / parameter routing

• process_networks / process_stis / process_demographics now raise on collisions instead of silently winning; separate_pars raises on pars ∩ kwargs collisions in both sti.Sim and hivsim.Sim. (#423)
• Improve “ambiguous parameter” error messages to name the offending par. (#423)
• hivsim.Sim pulls network-level kwargs from user input into the default StructuredSexual instance. (#423)
• Remove BreastfeedingNet from sti.Sim default networks; only relevant for diseases with postnatal transmission (HIV, syphilis). (#406, #444)

Bug fixes

• Fix birth data key mismatches in process_demographics when use_pregnancy=False: 'births' → 'cbr'/'birth' keys, file path, and metadata columns. (#411, #428)

Documentation

• Switch docs build from MkDocs to Quarto; convert tutorials from .ipynb to .qmd. (#439)
• Documentation audit and uplift via IDM standards plugin (folder READMEs, API reference, navigation polish). (#435)
• Add new publication entry: Stuart et al., “Estimating the value of novel tests for active syphilis in Zimbabwe…” forthcoming in STD. (#447, #448)

Tests

• Add tests/devtests/devtest_sw_networks.py with 10 integration tests covering MF only, SW only, MF+SW modular, StructuredSexual, implicit-SW thresholds, windowed entry/exit, and all sti.Sim / hivsim.Sim / hivsim.demo creation patterns. (#445)
• Add test_shorter_sw: shorter SW participation window → fewer FSW-attributable transmissions. (#445)
• Remove fragile len(sim.diseases/networks/interventions) count assertions in test_sim. (#444)
• Remove fragile test_doubling_hiv_sexual_beta. (#445)
• Regenerate baseline.yaml to reflect default behaviour changes (windowed SW, BreastfeedingNet removal, Bellan acute pars). (#426, #444, #445)

Version 1.5.3 (2026-04-17)

Interventions

• Extract shared coverage-targeting logic into interventions/utils.py: parse_coverage, age_sex_mask, compute_coverage_target (#328)
• Replace _parse_age_bin with starsim’s ss.parse_age_range and ss.apply_age_range (#326)
• Expose smoothness parameter for coverage interpolation (default 0 = linear) (#327)
• Support mixed n/p coverage format: historical absolute numbers transitioning to projected proportions within a single DataFrame or dict (#383)
• Remove deprecated coverage_data and future_coverage parameters; use coverage instead (#383)
• Refactor PrEP to use parse_coverage (#327)
• Add pmtct_efficacy parameter to ART (default 0.96), replacing hardcoded rel_sus=0 for prenatal MTCT protection (#404)
• Extend PMTCT protection to breastfed infants via BreastfeedingNet (#407)
• Add ANC HIV testing pattern using HIVTest with pregnancy eligibility (#322)

HIV / MTCT

• Add new_infections_mtct, new_infections_sex, new_infections_prenatal, new_infections_postnatal results to BaseSTI (#325)
• Implement breastfeeding HIV transmission via BreastfeedingNet with beta_breastfeed parameter (#323)
• Add p_diagnosed_pregnant result tracking ANC testing coverage (#322)
• Include BreastfeedingNet in hivsim.Sim defaults (conditional on Pregnancy module)

Bug fixes

• Fix chlamydia eff_condom default: updated to 0.4 based on linked citation (#391)
• Fix hivsim.Sim: conditionally add BreastfeedingNet only when Pregnancy is present (#413)
• Fix disease count assertion in test_sim_creation (#413)

Documentation

• Add examples gallery with first entry: Modeling ART interruptions (#394)
• Add PMTCT section to HIV user guide (ANC testing, prenatal/postnatal protection)
• Document HIV transmission route results (MTCT, prenatal, postnatal)
• Add docstrings across interventions, diseases, networks, and analyzers (#409)

Tests

• Add test_pmtct: 8-sim combinatorial test for ANC testing, PMTCT efficacy, and breastfeeding duration
• Add test_mtct: prenatal + postnatal MTCT consistency checks

Version 1.5.2 (2026-04-06)

Bug fixes

• Fix default_build_fn to apply rand_seed when reseed=True, so each calibration trial uses its own seed
• Fix timepar handling in data loaders (remove unnecessary TimePar catch)
• Fix stray plot appearing when running pytest (test_zimbabwe called hivsim.demo with plot=True)

Improvements

• Add HIV.plot() with curated 6-panel view (new infections, deaths, prevalence, prevalence 15-49, diagnoses, proportion on ART)
• Pin starsim>=3.3.1 and sciris>=3.2.9

Tests

• Add baseline regression test and benchmark test using Zimbabwe HIV example
• Refactor test suite with clear file responsibilities: test_sim.py (constructor/routing), test_hiv.py (HIV scientific validation), test_stis.py (non-HIV STI validation), test_networks.py (network dynamics)
• Add hivsim.Sim constructor tests (defaults, parameter routing, custom modules)
• Add HIV sensitivity tests: test_par_ranges checks beta_m2f, init_prev, dur_falling, and art_efficacy against both cum_infections and cum_deaths
• Add test_prevalence_by_sex verifying female > male HIV prevalence under defaults
• Add MSM network test
• Rename test_diseases.py to test_stis.py, test_hiv_natural_history_verification.py to test_hiv.py
• Merge test_examples.py into test_sim.py

Documentation

• Fix calibration tutorial to use disease instances instead of strings
• Add note about scikit-learn requirement for plot_param_importances

Version 1.5.1 (2026-03-27)

Bug fixes

• Fix VMMC eligibility: pass eligibility to parent class and use check_eligibility() in step(), so user-supplied eligibility functions are no longer silently ignored (#353)
• Fix starsim compatibility: convert ss.years/ss.date to int in get_age_distribution() for newer starsim __len__ behavior
• Fix rand_seed placement in beta transmission test (#354)

Parameter handling

• Remove parameters from SimPars that duplicate starsim’s Sim (label, verbose, total_pop, pop_scale, birth_rate, death_rate, use_aging) (#351)
• Add get_valid_pars() to detect ambiguous parameters across namespaces (#351)
• Improve error messages for unrecognized parameters with suggestions via sc.suggest() (#351)
• Handle location/demographics conflict in remap_pars() (#351)
• mergepars() now returns sc.objdict for dot-notation access (#351)

Other changes

• Delete legacy setup.py (use pyproject.toml)
• Relax sc.require to only check starsim, with die=False
• Comment out unused dt parameter in Migration

Tests

• Add VMMC tests: reduces male infections, male-only targeting, eligibility targeting (#251, #355)
• Add ART dropout tests: CD4 decline and rel_trans increase after stopping ART (#244)
• Add exponential early-phase epidemic growth test (#260)
• Add increased testing speeds diagnosis test (#253)
• Add no-HIV-without-seeding test (#271)

Documentation

• Fix sti.Pregnancy → ss.Pregnancy in Getting Started tutorial (#343)
• Fix tutorials and user guide nav nesting
• Update syphilis docs: exposed stage, treatment/reinfection, key properties
• Fix HIV dur_on_art default in docs

Version 1.5.0 (2026-03-13)

Interventions

• Refactor ART and VMMC coverage input: accept scalar, dict, or DataFrame formats with flexible column names (#126)
• Add art_coverage analyzer for tracking ART coverage by age and sex
• Simplify art_initiation: accept plain number, drop init_prob backward compat
• Guard pregnancy/maternalnet access in HIV and syphilis interventions so they work without a pregnancy module (#319)
• Document HIV intervention pipeline and ordering (#314)

HIV

• Add aids property to HIV module (cd4 < 200)
• Fix dur_on_art being silently scaled by dur_on_art_trend: default is now None (#336)
• Add time-varying ART duration and wider care-seeking distribution
• Add custom module support to Sim constructor (#318)

Syphilis dynamics

• Fix Syphilis.infect(): use rel_trans=1 for maternal transmission, stage-specific for sexual
• Fix NewbornTreatment to detect MTC-infected babies (susceptible=False, congenital not yet fired)
• Fix congenital syphilis over-counting: clear ti_* after events fire, mark babies non-susceptible after MTC
• Add step_die to Syphilis to clear states on death
• Add n_infections counter and new_reinfections result

Calibration API

• New dot-notation parameter routing: 'hiv.beta_m2f' automatically finds and sets the right module parameter via sim.get_module() (requires Starsim 3.2.0+)
• Support nested parameter format: dict(hiv=dict(beta_m2f=dict(low=..., high=...))) alongside flat {'hiv.beta_m2f': dict(...)}
• Add flatten_calib_pars() to normalize between nested and flat formats
• Add set_sim_pars(sim, pars) for setting calibrated parameters on any sim (pre- or post-init)
• Add Calibration.get_pars(n) to extract top-N parameter sets as flat dicts
• Add make_calib_sims() for creating and running sims from calibrated parameters, with filtering (check_fn) and seed replication (seeds_per_par)
• Add Calibration.save() method for shrink/save workflow (replaces manual shrink + saveobj boilerplate)
• No custom build_fn needed – default_build_fn handles all module types automatically

Documentation

• Add calibration tutorial with ABC philosophy, custom analyzer fitting, production workflow
• Update co-transmission tutorial: HIV-syphilis example with epidemiological explanation of connector effects
• Add custom results section to results tutorial
• Cross-link calibration and results tutorials

Tests

• Add HIV natural history verification test suite: CD4 decline, transmission doubling, MTCT, AIDS property (#178, #226, #227, #228, #237, #238, #295)
• Add HIV intervention tests: ART coverage formats, duration, effects, parameter sensitivity
• Add testlib.py with shared build_testing_sim() helper

Version 1.4.9 (2026-02-24)

• Add default_build_fn for calibration: routes parameters by prefix (hiv_*, syph_*, nw_*) to diseases and networks automatically, removing need for custom build_fn
• sti.Calibration now uses default_build_fn when no build_fn is provided
• Fix make_df() time column to use years from timevec instead of integer index
• Fix parse_study() to guard sim_results reordering when save_results=False
• Fix calibration data column names to use dot notation (hiv.prevalence)
• Standardize import conventions: import stisim as sti, import hivsim (no alias)

Version 1.4.8 (2026-02-23)

• Add hivsim_examples package with simple and zimbabwe pre-configured examples
• Add hs.demo() function for quickly running example HIV simulations (e.g. hs.demo('zimbabwe'))
• Add Sim.plot() override that auto-selects curated HIV result keys when HIV is present
• Add data parameter to sti.Sim for passing comparison data (e.g. UNAIDS estimates) to starsim’s plot overlay
• Fix process_demographics() to use total_pop from sim_pars when set, and correctly scale age data (values in thousands)
• Fix separate_pars() so kwargs override sim_pars defaults (e.g. stop=1995 overrides sim_pars=dict(stop=2025))
• Fix get_age_distribution() to handle CSV files without a year column

Version 1.4.7 (2026-02-20)

• Fix bugs in coinfection analyzer: age limit typo, variable name errors for male results
• Remove STIsim Pregnancy module, now superseded by the Starsim Pregnancy module
• Add exposed/incubation period for syphilis (dur_exposed), and allow maternal transmission during this stage
• Rename syphilis birth outcome key active to mat_active to reflect inclusion of exposed stage
• Add .vscode/ and *.code-workspace to .gitignore

Version 1.4.6 (2026-02-20)

• Add sensible beta_m2f defaults for all diseases (NG: 0.06, CT: 0.06, TV: 0.1, HIV: 0.05, syphilis: 0.1)
• Add rel_trans_hiv_ng parameter to the HIV-NG connector
• Fix connector handling in Sim.init() when a single connector is passed
• Set auto_plot=False on subpopulation, care-seeking, and detail results so sim.plot() shows only high-level results
• Add tutorials: intro (gonorrhea), co-transmission, results/plotting, and interventions
• Add user guide pages for interventions (testing, treatment, ART, VMMC, PrEP)
• Update disease docs with beta_m2f defaults and per-act description
• Pre-build font cache in docs CI workflow

Version 1.4.5 (2026-02-20)

• Fix BV trimester KeyError during initialization
• Add documentation: intro tutorial, disease reference pages, and network guide
• Configure mkdocs to execute notebooks and add user guide structure
• Update README with Python/R install instructions and example repos
• Move devtests to tests/devtests/ and rename test_hiv to devtest_hiv

Version 1.4.3 (2025-12-08)

• Patch to add super calls to init_results for analyzers
• GitHub info: PR 160

Version 1.4.2 (2025-11-28)

• Patch to ensure that products have different names
• Add ti_exposed attribute to HIV module
• GitHub info: PR 150

Version 1.4 (2025-08-12)

• Add location arg and Sim class
• Update to work with Starsim v3.
• GitHub info: PR 148

Version 1.3 (2025-06-27)

• Fixes to the pair-matching algorithm within the sexual network to better align partner ages
• Improvements to networks, including analyzers for debut age and partner age differences
• GitHub info: PR 143

Version 1.2 (2025-06-10)

• Improvements to networks, including analyzers for relationship duration and network degree
• Adds a PriorPartners network for recalling past relationships - for use in partner notification
• GitHub info: PR 135

Version 1.1.2 (2025-06-03)

• Bugfix to calibration class for multisims
• GitHub info: PR 138

Version 1.1.1 (2025-05-23)

• Bugfixes to calibration class and BV connector
• Replaces the match_pairs method of the StructuredSexual network with the faster option that was previously in the FastStructuredSexual network (now removed).
• GitHub info: PR 124

Version 1.1.0 (2025-05-13)

• Improvements to the Calibration class: this class now inherits directly from the Starsim calibration class, so users will have access to easier parameter constraints, plotting, flexible fit functions, etc
• Generalization of the coinfection class to handle any two diseases
• Addition of a more detailed BV model
• GitHub info: PR 119

Version 1.0.5 (2025-05-08)

• Adds results for syphilis transmission by disease stage
• GitHub info: PR 112

Version 1.0.4 (2025-05-07)

• Adds results for overtreatment among pregnant women
• GitHub info: PR 111

Version 1.0.3 (2025-04-30)

• Bugfixes for congenital syphilis
• GitHub info: PR 85

Version 1.0.2 (2025-04-14)

• Bugfixes for syphilis and GUD
• GitHub info: PR 83

Version 1.0.1 (2025-03-31)

• Track HIV prevalence for 15-49 year olds
• GitHub info: PR 79

Version 1.0.0 (2024-12-11)

• Updates to work with Starsim v2.2.1
• GitHub info: PR 63

Version 0.2.0 (2024-11-01)

• Updates to work with Starsim v2.0
• GitHub info: PR 62

Version 0.1.0 (2024-10-02)

• Collection of updates related to the NG/CT/TV work
• GitHub info: PR 59

Version 0.0.2 (2024-06-07)

• Initial version of STIsim with structured sexual networks, models of HIV and syphilis, worksflows for model calibration, and interventions for testing and treatment.
• GitHub info: PR 22

Version 0.0.1 (2024-05-15)

• Pre-release version