Weekly U.S. Influenza Surveillance Report

CDC's Influenza Division produces a weekly influenza surveillance report, FluView. According to this week's report (Oct 14-20), seasonal influenza activity is at levels below baseline in the United States. During last week's report, the first pediatric death was reported to CDC for the 2018-19 season.

Learn More

Synopsis:

Influenza activity in the United States remains low. Influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B viruses continue to co-circulate, with influenza A(H1N1)pdm09 viruses reported most commonly by public health laboratories during the most recent three weeks. Below is a summary of the key influenza indicators for the week ending October 20, 2018:

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 1.5%, which is below the national baseline of 2.2%. All regions reported ILI below their region-specific baseline level.

ILI State Activity Indictor Map: Puerto Rico and one state experienced low ILI activity; and New York City, the District of Columbia, and 49 states experienced minimal ILI activity..

Geographic Spread of Influenza: The geographic spread of influenza in four states was reported as local; the District of Columbia, Puerto Rico, the U.S. Virgin Islands and 42 states reported sporadic activity; four states reported no activity; and Guam 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: No influenza-associated pediatric deaths were reported to CDC.