Free tool · Estimator
Legionnaires' exposure window estimator
If you have been diagnosed with Legionnaires' disease, the source is usually somewhere you were 2 to 10 days before symptoms began. Enter your symptom-onset date to see that window.
Not medical advice
This is general information, not a diagnosis or medical advice. If you are unwell, contact a doctor or call NHS 111. Only a clinician can diagnose Legionnaires' disease.
A planning aid to help you and public health think about where to look — not a diagnosis. Sources:NHS — Legionnaires' disease,CDC — about Legionella.