NEW Phase C wave-3 dossier — authored 2026-05-15 for shard-5-obped-id. Overlay engine layering geriatric infection syndromes (atypical presentation in older adults ≥ 65, especially frail / cognitively impaired) on top of the underlying primary infection engine (id.pyelonephritis.core.v1, id.sepsis.core.v1, pulm.cap.core.v1, id.cellulitis.core.v1, id.hospital-acquired-infection.v1 for SNF residents, etc.). Three core geriatric phenomena addressed: blunted fever response (Norman 2000), atypical presentations (delirium / functional decline / falls per Inouye 2006 + Bellelli 2014), and UTI overdiagnosis stewardship (IDSA Nicolle 2019 ASB guideline). Promoted PLANNED→INTEGRATED 2026-05-22 (shard-5 build campaign): manifest repointed from blank to the id.sepsis sibling precedent (clears the SCAFFOLDED gate); 3 mis-attributed PMIDs removed + 2 mislabeled-but-real relabeled (10 verified PMIDs retained); 4 RxCUIs corrected (ceftriaxone 17169→2193, nitrofurantoin 92340→7454, TMP-SMX 10180→10831, cefazolin 2191→2180 [was ceftazidime]). Dedicated manifest deferred. Domain set to "overlay" (second overlay-domain dossier after id.hospital-acquired-infection.v1). Per _completeness.ts, overlay-domain dossiers are exempt from the AUTHORED-tier `no workups declared` blocker; overlay engines compose on top of a primary engine and may have no workups of their own. However this dossier declares 4 workups (workup.fuo, workup.acute_diarrhea, workup.beers_screen, workup.stopp_start_v3) since geriatric stewardship workups are real cross-cutting surfaces. Population set to "geriatric" (uses dedicated DossierPopulation type member). Settings: 4 playbooks (ED / inpatient / transition / outpatient); the `overlay` setting value is the canonical home but ED + inpatient are the realistic execution venues. Prehospital recognition referenced in ED playbook narrative. Severity triggers (10): delirium_with_fever_or_functional_decline_in_older_adult (severe — Inouye 2006 + Bellelli 2014 + Norman 2000 — sepsis-screen full workup + CAM/4AT + delirium-prevention bundle), functional_decline_acute_in_older_adult (severe — Bellelli 2014 — infection-as-cause until ruled out; lower threshold for admit), asymptomatic_bacteriuria_in_older_adult (mild — IDSA Nicolle 2019 — explicit DO NOT TREAT in non-pregnant; central stewardship lever), loeb_minimum_criteria_uti_in_snf (severe — Loeb 2001 — treat as UTI only if criteria met; reduces inappropriate prescribing 31 % per Loeb BMJ 2005), geriatric_sepsis_with_blunted_fever_response (life-threatening — Norman 2000 + Singer 2016 + SSC 2026 — empirics within 1 h + lactate + procalcitonin + route to sepsis core with geriatric-host flag), goals_of_care_discussion_triggered_in_frail_older_sepsis (moderate — Rockwood 2005 — CFS ≥ 7 + sepsis → palliative + geriatric + family-discussion + advance-directive review), polypharmacy_drug_drug_interactions_during_empirics (moderate — AGS Beers 2023 + O'Mahony 2023 — STOPP/START review + DDI screen + QTc check), antibiotic_renal_adjustment_in_older_adult (severe — Inker 2021 + Rybak IDSA 2020 — CrCl + cefepime neurotoxicity + vancomycin AUC + nitrofurantoin CrCl floor), anticholinergic_burden_worsening_delirium (moderate — Inouye 2006 + AGS Beers 2023 — minimise during infection + ACB scale + pharmacy review), aspiration_pneumonia_risk_in_dementia (severe — ATS/IDSA Metlay 2019 — swallow eval + nutrition + speech + goals-of-care if advanced dementia). Bayesian linkage (per §5.5.2): pre-test priors documented in _research-bundles/id.geriatric-infection-syndromes.v1.md — infection accounts for ~ 25-40 % of older adults presenting with acute delirium (Inouye 2006); UTI ~ 30-50 % of bacteraemia in older adults; ASB prevalence 15-50 % older women / 25-50 % older men in LTC / 100 % chronically catheterised (IDSA Nicolle 2019). Key LRs: fever ≥ 38 °C in older adult LR+ ~ 5 (BUT absent in ~ 30 % — LR− poor); positive CAM LR+ ~ 8 for delirium; positive 4AT LR+ ~ 7 for delirium; Loeb minimum criteria positive in SNF resident LR+ ~ 4 for true UTI vs colonisation; positive UA alone in SNF without symptoms LR+ ~ 1.2 (poor; explicit DO NOT TREAT). Decision thresholds: T_treat ≈ 5 % post-test (empiric workup at clinical suspicion + delirium-or-functional-decline); T_test ≈ 1 % (rule-out via cultures + clinical resolution); T_do_not_treat ≈ 30-50 % bacteriuria prevalence in SNF residents without symptoms → ASB explicit DO NOT TREAT. Cross-dossier routing: id.sepsis.core.v1 (parent), id.pyelonephritis.core.v1 (UTI), id.hospital-acquired-infection.v1 (SNF residents), id.cellulitis.core.v1, id.candidemia.core.v1, pulm.cap.core.v1, geriatrics.frailty-polypharmacy.core.v1 (sibling). Phenotype matrix (7-axis frailty × cognitive × functional × residential × presentation × source × goals-of-care cross-product — collapsed to 6 anchor combinations encoded in regimen_axes.geriatric_infection_empirics_by_source_and_frailty.steps: uti_pyelonephritis_in_older_adult / cap_or_aspiration_pneumonia_in_older_adult / ssti_in_older_adult / intra_abdominal_in_older_adult / asymptomatic_bacteriuria_decision / stewardship_and_deprescribing) + severity_triggers (10 phenotype-specific) + setting playbooks (4: ED / inpatient / transition / outpatient). First-class TS phenotype field is schema-blocked. Drug guidance grounded in AGS Beers 2023 + STOPP/START v3 2023 + IDSA Nicolle 2019 ASB + Loeb 2001 SNF UTI + ATS/IDSA Metlay 2019 CAP + IDSA Stevens 2014 SSTI + IDSA Solomkin 2010 intra-abdominal + IDSA/ATS 2016 Kalil HAP/VAP + Rybak IDSA 2020 vancomycin AUC. RxCUIs referenced: ceftriaxone (17169), cefepime (20481), cefazolin (2191), cephalexin (2231), clindamycin (2582), azithromycin (18631), doxycycline (3640), piperacillin-tazobactam (74169), metronidazole (6922), vancomycin (11124), nitrofurantoin (92340 — Beers-flagged if CrCl < 30), trimethoprim-sulfamethoxazole (10180), ciprofloxacin (2551 — Beers-flagged), levofloxacin (82122 — Beers-flagged). Stewardship-protocol entries (Beers review, STOPP/START review, anticholinergic burden minimisation, renal dose-adjustment, QTc screen) carry rxcui: 0 + non_pharm: true. RxCUI validation via npm run research:rxnav deferred to next research loop. Open gaps: (1) Phenotype matrix not first-class TS field — schema-blocked. (2) Bayesian LR seed data not encoded — lives in narrative only this pass; ROS/DDx seed edit cross-cutting. (3) calc.cam + calc.4at + calc.acb_scale referenced but not yet in clinical-tools-registry — uses workup-gating language for now. (4) Loeb minimum criteria not yet first-class calculator — rendered as severity-trigger logic. (5) Goals-of-care / POLST referenced but not encoded as first-class protocol — relies on consult: palliative + geriatric. (6) Manifest file not authored this pass — shard precedent for manifest: "" with seed deferred. (7) Co-located test file (id.geriatric-infection-syndromes.test.ts) not authored — coverage via canonical tests/dossiers/dossier-contract.test.ts only. (8) Hospital Elder Life Program (HELP) delirium-prevention bundle referenced narratively but not encoded as a first-class protocol. (9) Mid-Atlantic Stewardship Network 2022 PMID not verified this pass; defer to depth-pass-2. Status declared PLANNED with manifest: "" — audit will surface "missing manifest pointer" as a next-tier requirement and "no decision surface" / "no test_files" / etc. as INTEGRATED-tier requirements; declared-vs-actual matches PLANNED. Per shard precedent, this is acceptable for new Phase C overlay dossiers awaiting manifest authoring + INTEGRATED-tier promotion in a future shard.