About FluHub
Sources, methods, and clinical review
Where every number comes from, how often it updates, and how clinical content is checked before it goes live.
Data sources
Definitions
- Influenza-like illness (ILI): fever of 100°F or higher with cough or sore throat. National %ILI is the population-weighted share of outpatient visits for ILI from ILINet providers; state values are unweighted.
- National baseline: the mean %ILI during non-flu weeks of the three previous seasons plus two standard deviations; 3.1% for 2025–26. CDC publishes the 2026–27 baseline with the first report of the season.
- Flu season and MMWR weeks: a season runs from MMWR week 40 through week 39 of the next year. MMWR weeks run Sunday to Saturday; week 1 is the first week with at least four days in the calendar year.
- Activity level (Very Low to Very High): CDC's acute respiratory illness level, based on the share of emergency department visits for respiratory illness compared with each state's own baseline. It includes COVID-19 and RSV, so it is broader than flu. It is distinct from FluView's 13-level ILI map. CDC publishes only the current week; FluHub archives each week.
- Typical range: the 10th to 90th percentile for each week across all prior seasons since 2010–11, excluding 2020–21 and 2021–22, when COVID-19 measures suppressed flu.
- Burden estimates: CDC's modeled counts of illnesses, visits, hospitalizations, and deaths; recent seasons are preliminary and are revised.
Refresh schedule
An automated job pulls every source each Friday afternoon (Eastern), after CDC publishes FluView, then rebuilds the site. Curated figures that CDC publishes as reports rather than data (burden, vaccine effectiveness, H5 counts) are reviewed against CDC monthly and whenever CDC announces an update.
Clinical validation workflow
- Source of record. Every clinical statement maps to a numbered source on the page: CDC guidance, an FDA label, an IDSA guideline, or a professional society statement, each with the version date that was checked.
- Physician sign-off. Parth Bhavsar, MD, board-certified family physician, reviews every clinical page and every symptom-checker outcome before publication and after any guideline change.
- Guideline watch. CDC (FluView, antiviral summary, vaccine clinical considerations), IDSA, AAP, ACOG, and AAFP are checked at the start of each season and monthly during it. A change triggers a review of every page that cites the changed source.
- Safety rules for the symptom check. Emergency signs are asked first and stop the flow. Results can only move people toward care, never away from it. Nothing a user enters is stored or sent anywhere.
- Conflicts are shown, not hidden. Where sources disagree (for example, FDA label versus CDC prophylaxis duration, or federal versus society vaccine schedules), the page says so and names which one FluHub follows.
Independence and disclosure
FluHub is published by TeleDirectMD, a physician-owned telehealth practice. Practice information appears only where a same-day adult visit is a reasonable next step and never on emergency results. FluHub takes no advertising and collects no personal health information.
Corrections
Email contact@teledirectmd.com. Corrections are made the same week and noted on the affected page.