Public information

Sources and Methodology

See how Hantavirus Outbreak Tracker uses official sources, case definitions, source labels, review rules, and update methods for outbreak data.

Last reviewed: May 12, 2026 View live tracker

Medical disclaimer

This page is for general public information only. It is not medical advice and is not a substitute for care from a clinician or guidance from your local public-health authority. If you may have been exposed to hantavirus or Andes virus and you develop symptoms, contact a medical professional or public-health authority promptly. If you have severe breathing difficulty or other emergency symptoms, seek emergency medical care.

Hantavirus Outbreak Tracker is an independent public-information site. It is not affiliated with CDC, WHO, ECDC, or any public-health authority.

The tracker is designed to make outbreak information easier to follow by summarizing public sources, linking back to those sources, and labeling the status of each data point.

Source hierarchy

When sources conflict, the tracker should prioritize sources in this order:

  1. Official public-health agencies directly responsible for the event.
  2. International public-health organizations, including WHO and ECDC.
  3. National, state, provincial, or regional health authorities.
  4. Official hospital, port, cruise operator, or transport statements when relevant.
  5. Reputable media reports, clearly labeled and not treated as official confirmation unless supported by an official source.

Primary sources

The tracker may use sources such as:

  • CDC hantavirus pages and health advisories
  • WHO Disease Outbreak News
  • ECDC outbreak updates, assessments, and rapid advice
  • National health ministries
  • State or local health departments
  • Official port, transport, or ship operator statements
  • Peer-reviewed or technical outbreak reports where relevant

Case-status labels

Every case count or event should be labeled. Recommended labels:

LabelMeaningUse in tracker
Official confirmedLaboratory-confirmed and reported by an official health authorityUse for confirmed case counts
Official probableReported by an official source as probable under a stated case definitionUse separately from confirmed cases
Official suspectedReported by an official source as suspected or under investigationDo not combine with confirmed without labeling
Monitored contactPerson under monitoring because of possible exposureDo not count as a case
Media reportedReported by reputable media but not yet officialUse only with clear caveat
Under reviewData point found but not yet reconciledKeep out of headline totals
Historical/backgroundStable context not part of current case countUse in explainers only

How case counts should be displayed

Confirmed, probable, suspected, monitored, hospitalized, recovered, and deceased counts should not be merged into one number unless the page clearly explains what the number means.

Recommended display:

  • Confirmed cases
  • Probable cases
  • Suspected cases
  • Deaths
  • Hospitalized cases
  • Monitored contacts
  • Countries or jurisdictions involved
  • Last updated timestamp
  • Source timestamp

If a source gives "total cases" and includes probable cases, the tracker should say that explicitly.

Conflict-resolution rules

When two sources disagree:

  1. Prefer the most recent official source directly responsible for the jurisdiction or event.
  2. If WHO/ECDC/CDC publish a later synthesis, use it as the main summary source and preserve jurisdictional details underneath.
  3. Do not silently overwrite a number without changing the source timestamp.
  4. If a media report is ahead of official sources, label it as media-reported and keep it out of official confirmed totals.
  5. If a person is later ruled out, update the relevant row as "non-case" or "removed after negative test" rather than deleting the historical explanation without trace.

Update cadence

The live tracker may update more often than the evergreen pages. The evergreen pages should be reviewed periodically, not rewritten daily.

Recommended cadence:

Content typeUpdate cadence
Live tracker numbersAs data pipeline permits
Current outbreak status cardDaily during active outbreak
Evergreen symptom/transmission/prevention pagesMonthly during active outbreak, quarterly afterward
FAQMonthly during active outbreak
Methodology pageWhen source or classification rules change
Schema and metadataAt launch, then after major page changes

What counts as a source

A source should be linkable, attributable, and dated where possible.

Good sources include:

  • Official agency pages
  • Official press releases
  • Health advisories
  • Situation reports
  • Epidemiological updates
  • Formal assessments
  • Peer-reviewed outbreak studies
  • Reputable news reports used only as secondary context

Weak sources include:

  • Unsourced social media claims
  • Screenshots without provenance
  • Aggregators that do not link to original sources
  • AI-generated summaries without primary links
  • Reposted numbers with no date or author

What the tracker does not claim

The tracker does not claim to:

  • Diagnose individual illness
  • Provide medical advice
  • Replace public-health instructions
  • Confirm cases independently without source support
  • Predict future case counts
  • Identify unreported cases
  • Determine legal responsibility for an outbreak
  • Give travel, quarantine, or isolation instructions

Editorial standards

Every page should follow these rules:

  • Write plainly.
  • Avoid panic language.
  • Preserve uncertainty.
  • Use official terminology.
  • Separate confirmed facts from developing reports.
  • Link to primary sources.
  • Show the last reviewed date.
  • Explain case definitions when using case counts.
  • Avoid implying that monitored contacts are confirmed cases.
  • Avoid implying that general-public risk is the same as exposed-contact risk.

Data-field recommendation

For each tracker row, store at least:

FieldDescription
event_idStable internal ID
date_reportedDate the source reported the data
source_nameName of source
source_urlCanonical source link
source_typeOfficial, international, regional, media, technical
jurisdictionCountry, state, region, ship, or facility
case_statusConfirmed, probable, suspected, monitored, non-case
countNumber reported
count_typeCases, deaths, hospitalizations, contacts, tests
summaryHuman-readable description
confidenceHigh, medium, low
last_checkedTimestamp when tracker checked source
display_flagWhether it appears in headline totals

Source register display

Add a visible source register table on this page with columns:

  • Source
  • Type
  • What it is used for
  • Update frequency
  • Last checked
  • Link

The table should be sortable and filterable, but it must also be readable as ordinary HTML.

Related pages

Source register

SourceTypeWhat it is used forUpdate frequencyLast checkedLink
CDCOfficial public-health agencyHantavirus background, Andes virus details, prevention, cleanup, and current situation contextAs agency updates2026-05-12Open source
WHOInternational public-health organizationDisease Outbreak News and multi-country outbreak contextAs agency updates2026-05-12Open source
ECDCInternational public-health organizationEuropean outbreak assessment and regional public-health adviceAs agency updates2026-05-12Open source
National and regional health authoritiesOfficial health authorityJurisdiction-specific case labels, contact monitoring, and public guidanceWhen new reports appear2026-05-12Open source
Verified media reportsSecondary sourceDeveloping context only when official sources are unavailable or delayedManual review only2026-05-12Open source

Primary sources reviewed

Primary sources reviewed: CDC, WHO, ECDC, and relevant public-health guidance.

Last reviewed: May 12, 2026.

Editorial note: This page summarizes official public-health sources and is written for general readers. It does not replace clinical guidance.