Table 1 Alert criteria for 2009 H1N1 pandemic general descriptions
From: Event-based internet biosurveillance: relation to epidemiological observation
| Alert | Description | Date of creation |
|---|---|---|
| Alert 1 | Large increase in case count (ie. resurgence, 50% increase in new cases from previous week) | November 5, 2009 (week 45) |
| Alert 2 | Large increase in fatalities (ie. 50% increase in fatalities from previous week) | October 1, 2009 (week 40) |
| Alert 3 | Confirmed cases or fatalities in healthcare workers, military personnel and/or national officials | July 7, 2009 (week 28) |
| Cluster (>3) military personnel, health care workers and/or national officials | November 5, 2009 (week 45) | |
| Alert 4 | Fatalities in cases with no underlying health conditions | July 9, 2009 (week 28) |
| Alert 5 | Severe manifestation, co-infection, re-infection (ie. encephalitis, atypical pneumonia, ICU admission with ventilator support, etc.) | July 30, 2009 (week 31) |
| Alert 6 | Reports of overwhelmed ICUs and ventilator shortages as a result of 2009 – H1N1 Influenza infection | July 30, 2009 (week 31) |
| Hospital/clinic infrastructure strain or collapse | October 1, 2009 (week 40) | |
| Alert 7 | Human-to-swine or swine-to-human transmission | July 9, 2009 (week 28) |
| Alert 8 | Infection in species other than human or swine | July 7, 2009 (week 28) |
| Alert 9 | Anti-viral resistance/failure; Non-traditional treatments | July 7, 2009 (week 28) |
| Alert 10 | Virus mutation/reassortment | July 7, 2009 (week 28) |
| Alert 11 | Vaccine failure, severe reaction, or black market sales | August 31, 2009 (week 36) |
| Alert 12 | Massive release of antiviral or vaccine stockpile | July 7, 2009 (week 28) |
| Alert 13 | Health policy change | July 9, 2009 (week 28) |
| Alert 14 | Food safety (ie. economic loss due to suspected or feared food product contamination) | July 7, 2009 (week 28) |
| Alert 15 | Border closures | July 9, 2009 (week 28) |