# VIRSTA Score Calculator (Tubiana 2016)

> VIRSTA Score Calculator (Tubiana 2016) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Calculates the Tubiana 2016 VIRSTA score (0–30) for infective endocarditis risk stratification in Staphylococcus aureus bacteremia using nine clinical flags plus CRP.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/virsta
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/virsta-score-calculator-tubiana-2016-f7731914
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xyopMRvCfiWOwud7mxQ5F

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability virsta-score-calculator-tubiana-2016-f7731914
```

Example prompt: Calculate the VIRSTA score for my patient with Staph aureus bacteremia — they have cerebral emboli (yes), meningitis (no), no intracardiac device or prior IE, IV drug use (yes), no native valve disease, persistent bacteremia (yes), no vertebral osteomyelitis, community-acquired (yes), no severe sepsis, and a CRP of 210 mg/L.

## When to prefer this

Use this endpoint when you need a fast, rule-based VIRSTA integer score for Staphylococcus aureus bacteremia risk stratification per the Tubiana 2016 derivation, with all nine clinical flags and CRP already determined by the clinician. Prefer over manual calculation when integrating into an automated SAB care pathway or clinical decision support agent. Not a substitute for echocardiography or infectious disease consultation.

## Known failure modes

- Missing any required boolean query parameter returns a validation error
- CRP value outside 0–500 mg/L range may be rejected or produce unexpected scoring
- Misclassification of caller-assigned flags (e.g. nosocomial vs community) leads to incorrect scores — the API accepts caller values without validation
- Score boundary misunderstanding: high_risk threshold is ≥ 3, not > 3

## How this service works

Tubiana 2016 VIRSTA from nine caller-assigned SAB flags plus CRP mg/L. Points: emboli 5, meningitis 5, device or previous IE 4 (one item), IVDU 4, native valve 3, persistent bacteremia 3, vertebral osteomyelitis 2, community/non-nosocomial 2, severe sepsis/shock 1, CRP >190 mg/L 1. Max 30. high_risk iff score ≥ 3. Not an endocarditis diagnosis.

## Output

Returns the total VIRSTA integer score (0–30) computed from the nine boolean clinical flags and CRP value, a high_risk boolean (true if score ≥ 3), and the individual point contributions of each criterion. Does not diagnose infective endocarditis.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "cerebral_or_peripheral_emboli",
      "meningitis",
      "intracardiac_device_or_previous_ie",
      "iv_drug_use",
      "native_valve_disease",
      "persistent_bacteremia",
      "vertebral_osteomyelitis",
      "community_or_non_nosocomial",
      "severe_sepsis_or_shock",
      "crp_mg_l"
     ],
     "properties": {
      "crp_mg_l": {
       "type": "number",
       "description": "C-reactive protein in mg/L (0-500). Tubiana 2016 scores 1 if CRP is above 190 mg/L (not ≥190). magent does not assay CRP."
      },
      "meningitis": {
       "type": "boolean",
       "description": "Caller-assigned meningitis (Tubiana 2016). true scores 5. magent does not diagnose meningitis or endocarditis."
      },
      "iv_drug_use": {
       "type": "boolean",
       "description": "Caller-assigned intravenous drug use (Tubiana 2016). true scores 4. magent does not take a social history."
      },
      "native_valve_disease": {
       "type": "boolean",
       "description": "Caller-assigned preexisting native valve disease (Tubiana 2016). true scores 3. magent does not diagnose valve disease."
      },
      "persistent_bacteremia": {
       "type": "boolean",
       "description": "H48-persistent bacteremia (positive blood culture after 48 hours) as assigned by the caller (Tubiana 2016). true scores 3. magent does not interpret cultures."
      },
      "severe_sepsis_or_shock": {
       "type": "boolean",
       "description": "Caller-assigned severe sepsis or septic shock (Tubiana 2016). true scores 1. magent does not diagnose sepsis."
      },
      "vertebral_osteomyelitis": {
       "type": "boolean",
       "description": "Caller-assigned vertebral osteomyelitis / spondylodiscitis (Tubiana 2016). true scores 2. magent does not diagnose osteomyelitis."
      },
      "community_or_non_nosocomial": {
       "type": "boolean",
       "description": "Community-acquired or non-nosocomia
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/virsta-score-calculator-tubiana-2016-f7731914/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)