CDC Weekly Flu Update - Week 41
Week ending in October 13, 2018
Last Updated October 22, 2018
ILI = 1.4
Influenza-Like Illness (ILI) Activity Geography Map
Summary of Influenza Activities
Viral Surveillance: Influenza A viruses have predominated in the United States since the beginning of July. The percentage of respiratory specimens testing positive for influenza in clinical laboratories was low.
- Virus Characterization: The majority of influenza viruses characterized antigenically and genetically are similar to the cell-grown reference viruses representing the 2018–2019 Northern Hemisphere influenza vaccine viruses.
- Antiviral Resistance: All viruses tested since late May show susceptibility to the antiviral drugs oseltamivir, zanamivir, and peramivir.
Influenza-like Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) remained low at 1.4%, which is below the national baseline of 2.2%. All regions reported ILI below their region-specific baseline level.
ILI State Activity Indictor Map: New York City, the District of Columbia, and 49 states experienced minimal ILI activity, and Puerto Rico and one state had insufficient data.
Geographic Spread of Influenza: The geographic spread of influenza in Guam and two states was reported as local activity; the District of Columbia, the U.S. Virgin Islands and 40 states reported sporadic activity; eight states reported no activity; and Puerto Rico did not report.
Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
Influenza-associated Pediatric Deaths: One influenza-associated pediatric death that occurred during the 2018-2019 season was reported to CDC.
The graphs and summary in this section are based on information available from the Weekly U.S. Influenza Surveillance Report found on the CDC website.