Methodology
How HantaCount counts cases. We aggregate, we do not invent. Every count on this site can be traced to a primary document listed on the sources page and edited via the changelog.
Inclusion criteria
A person enters the dataset only when at least one of the definitions below is satisfied and a named source documents it. We classify every case as confirmed, probable or suspected. Contacts under monitoring are tracked separately and never counted as cases.
Positive RT-PCR for hantavirus RNA, IgM seroconversion, or autopsy with virologic confirmation.
Compatible clinical syndrome (HCPS or HFRS) plus epidemiologic link to a confirmed case or known cluster, per the WHO DON-599 case definition.
Compatible illness in a person with credible exposure (e.g. Hondius passenger or close contact), pending lab result.
We publish the union of confirmed + probable + suspected as the headline count, mirroring WHO DON practice. The JSON dataset breaks this out per country in the note field.
Source priority hierarchy
When two sources disagree, the higher tier wins. We never promote a tier-1 wire over a national health agency on the same fact.
- 1WHO Disease Outbreak News
Highest authority for global cluster totals, case definitions and geographic spread.
- 2National health agency
RIVM (NL), Argentina MoH, US CDC, Spain Sanidad, etc. Authoritative for that country's count.
- 3ECDC Rapid Risk Assessment
EU-level synthesis; we use it for risk framing and tracing guidance.
- 4Primary research (peer-reviewed)
BMJ, Lancet, NEJM. Used for clinical context, virology, R0 estimates — not headline counts.
- 5Tier-1 news wires
Reuters, AP, AFP. Used to corroborate and time-stamp; never to introduce new cases without an upstream document.
- 6Regional outlets
Used cautiously, only when they cite a named official. Annotated as such in the source register.
De-duplication rules
- • A single person is counted in one country only — the country of the agency that confirmed or first reported the case (typically the country of treatment).
- • When two agencies independently report what is almost certainly the same person (e.g. nationality vs. country of treatment), we keep the country of treatment and add a note explaining the cross-reference.
- • Deaths follow the case, not the country of death — a Dutch passenger who dies in Cabo Verde is a Dutch death.
- • Contacts are tracked under
contactsTraced; they are not added tototalCasesunless and until a clinical or lab criterion is met.
Update frequency
- • Counts are reviewed every working day. Material changes are pushed to IndexNow within minutes; the homepage and /api/cases are CDN-cached for 10 minutes.
- • A snapshot of the full dataset is frozen daily at 23:59 UTC and exposed at
/api/cases/<YYYY-MM-DD>. Index: /api/cases/index. - • Every edit lands on the changelog with the contributing source IDs.
Disagreement handling
When sources diverge — a national agency reports 4 cases while a wire service quotes 5 — we prefer the higher-tier source and annotate the discrepancy in the country note. Specifically:
- • WHO vs. national agency, same country: national agency wins for that country; WHO wins for the multi-country total.
- • National agency vs. wire: national agency wins. Wire is held in pending until corroborated.
- • Two national agencies on the same person: country of treatment wins; country of nationality is annotated.
Why our count differs from other trackers
HantaCount учитывает все случаи, о которых сообщают официальные источники (ВОЗ, ECDC, национальные органы здравоохранения), включая как подтверждённые (PCR-верифицированные), так и подозрительные случаи в стадии расследования. Наш итог может отличаться от данных ВОЗ, которая считает только подтверждённые случаи.
Some dashboards report headline numbers like 35 cases / 19 countries. Ours, today, is 16 cases / 3 deaths / 14 countries. The gap is methodological, not factual.
| Counted as a case | Other trackers | HantaCount |
|---|---|---|
| Asymptomatic monitored contact | Often yes | No — kept in contactsTraced |
| Country with traced passengers, no case | Often counted as “affected country” | No — country list shows 0 cases until a criterion is met |
| Same patient reported in two countries | Sometimes double-counted | Counted once — country of treatment |
| Suspected case mentioned only by regional outlet | May be added immediately | Held in pending until tier-1 or agency confirmation |
| PCR-negative traveller | Sometimes still listed | Removed from suspected |
We err on the conservative side. Numbers should not move backwards if a contact later tests negative; the dataset stays defensible to a peer reviewer.
Limitations
- • Reporting lag. Confirmation typically lags symptoms by 3–7 days. The same-day count is always provisional.
- • Asymptomatic and mild cases missed. No serosurvey is yet available; the count is biased toward hospitalised disease.
- • Lab-access bias. Countries without BSL-3-equivalent capacity for ANDV PCR may under-report. We annotate when a country is awaiting external lab confirmation.
- • Cause-of-death attribution. Some early deaths were initially classified as community-acquired pneumonia and only later linked to ANDV. Historical numbers may be revised — every revision is in the changelog.
Versioning & archive
Every published count is immutable in the snapshot archive. Researchers can cite the dataset as it appeared on a given date, not as it appears today.
Questions?
For methodology critiques, custom slices, or to flag a missing source, email hello@hantacount.com. We respond on the record.