How a warning is computed

No black box: the six steps the SENTINARA engine runs every week, shown with the real numbers it used for a chosen country.

Key facts

• Step 1: read the monthly cases reported to WHO and drop the current and partially reported months.
• Step 2: compare the latest month with the same month in the previous five years (endemic channel): Success 0 points, Safety 0.5, Alert 1.5, Epidemic 3.
• Step 3: outbreak score (Farrington-style): (observed - expected) / (99.5% upper bound - expected) using the same month ±1 in the previous five years; above 0.5 adds 1 point, above 1 adds 2.
• Step 4: one-sided CUSUM on seasonally adjusted residuals; an alarm (4 or more) while cases are above the median adds 1 point.
• Step 5: probability that the next three months exceed the epidemic threshold, used only when the forecast beats a naive benchmark (20%: 1 point, 50%: 2); momentum of 30% or more above the median adds 1.
• Step 6: 1.5 points or more = Watch, 3 = Alert, 4.5 = Outbreak signal; the Epidemic zone is at least Alert, and irregular reporting is capped at Watch.

Data updated 2026-10-31. Sources: WHO Global Dengue Surveillance; OpenDengue V1.3 (Clarke et al., 2025), doi:10.6084/m9.figshare.24259573; Dinas Kesehatan Kota Semarang; World Bank Open Data; NASA POWER.