Arboviral Red-Flag Predictor Gen 1

1. Syndrome-led red-flag entry

Patient age group Exposure route most supported Geographic / ecological context Local surveillance signal

Symptoms and signs

Fever / acute viral syndrome Severe headache / myalgia / vomiting Neck stiffness / photophobia / meningismus Confusion / altered mental status Seizure Acute focal or flaccid weakness / areflexia Respiratory weakness Rash or swollen lymph glands

Select clinical features and run the model.

2. Syndrome-to-virus disambiguation flowchart

Gate A: acute syndromeFever, headache, myalgia, vomiting, rash or fatigue. Without this, arboviral disease is less likely, but not excluded.

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Gate B: neurological involvementMeningitis, encephalitis, seizure, focal deficit, acute flaccid weakness or respiratory compromise.

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Gate C: routeMosquito, tick, travel-associated mosquito exposure, or uncertain because the exposure history has not been elicited.

Gate D: ecologySeason, region, wetlands, woodland/deer ecology, local mosquito traps, public-health alerts and travel map.

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Gate E: disambiguationPush toward WNV, EEE, SLE, La Crosse, Jamestown Canyon, Powassan, Japanese encephalitis or wider arboviral panel.

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Gate F: actionUrgency, test selection, infection/neurology consultation and public-health reporting prompt.

Default branching logic

Pattern	Most plausible branch	Reasoning cue
Older adult + mosquito season + encephalitis or flaccid weakness	West Nile virus	Commonest domestic arboviral neuroinvasive candidate in North America; acute flaccid myelitis is a key red flag.
Severe encephalitis + seizure/coma + eastern/wetland exposure	Eastern equine encephalitis	Rare but high-severity; do not wait for familiarity before escalating.
Child/adolescent + wooded mosquito exposure + seizure/encephalitis	La Crosse virus	Paediatric neuroinvasive pattern is the key prompt.
Older adult + encephalitis + local activity overlapping WNV	St Louis encephalitis	Clinically overlaps with WNV; surveillance and laboratory testing disambiguate.
Adult + woodland/deer mosquito ecology + meningitis/meningoencephalitis	Jamestown Canyon virus	Under-recognised; ecology should trigger the question.
Tick exposure + meningoencephalitis	Powassan virus	Exposure route moves the reasoning out of the mosquito branch.
Recent rural Asia/western Pacific travel + encephalitis	Japanese encephalitis / travel arbovirus	Travel prevents domestic anchoring.

3. Clinician action panel

Emergency override: acute confusion, seizure, coma, acute flaccid paralysis or respiratory weakness should trigger urgent assessment regardless of the calculated score.

Clinical state	Suggested decision-support action
Febrile viral syndrome only	Check geography, season and local surveillance. Provide return precautions.
Meningitis pattern	Include arboviral meningitis in differential where season/exposure supports it; consider CSF testing.
Encephalitis pattern	Urgent neuroinfectious pathway; include HSV, bacterial meningitis, WNV and regional arboviruses.
Acute flaccid weakness	Flag WNV and other neurotropic infections; assess respiratory involvement and reflexes.
Tick exposure	Shift branch to Powassan and other tick-borne CNS infections; do not overfit to mosquito diseases.

4. Cognitive bias guardrail

This layer exists because the clinical failure is often not lack of intelligence but lack of activation: the right diagnosis is not in the working set.

Bias or failure mode	Countermeasure
Anchoring on “viral illness”	Neurological signs force movement out of the benign viral branch.
Premature closure	Ask: does the favoured diagnosis explain fever + neurological signs + season/exposure?
Availability bias	Display current regional activity and seasonality.
Base-rate neglect	Rare condition, severe outcome: low threshold for inclusion in differential.
Geographic unfamiliarity	Show region-specific arboviral candidates and surveillance links.

5. Product roadmap: from NileGuard to ArbovirusGuard

Module 1: NileGuard — West Nile red-flag predictor.

Module 2: Arboviral disambiguation layer — syndrome-led routing across West Nile, EEE, SLE, La Crosse, Jamestown Canyon, Powassan and travel-associated arboviruses.

Module 3: Live surveillance integration — public-health alerts, mosquito pools, tick geography, weather/ecology and seasonality.

Module 4: Clinician-facing diagnostic safety tool — red flags, testing prompts, differential diagnosis, cognitive bias warnings and documentation support.

This Gen 1 demonstrator is an educational and design prototype. It is not a diagnostic device and does not replace emergency assessment, infectious disease consultation, neurology consultation, laboratory testing or public-health reporting.