According to this week’s FluView report, overall flu activity remains low nationally although small increases in flu activity were reported. Five states (Kentucky, Massachusetts, North Dakota, Oregon, and West Virginia) are now reporting local flu activity; however 43 states, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands continue to report only sporadic flu activity. Influenza A(H1N1)pdm09 viruses have been the most commonly identified flu viruses in the last three weeks. CDC also reported an additional flu-associated pediatric death that occurred during the 2018-2019 flu season.
An annual flu vaccine is the best way to protect against influenza and its potentially serious complications. There are many benefits to vaccination, including reducing the risk of flu illness, doctor’s visits, hospitalization, and even death in children. There are many vaccine options. CDC recommends that everyone 6 months and older get vaccinated as soon as possible.
Influenza-like Illness Surveillance: For the week ending October 27 (week 43), the proportion of people seeing their health care provider for influenza-like illness (ILI) was 1.7% and remains below the national baseline of 2.2%. All 10 regions reported a proportion of outpatient visits for ILI below their region-specific baseline levels. Additional ILINet data, including national, regional, and select state-level data for the current and previous seasons, can be found at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.
Influenza-like Illness State Activity Indicator Map: New York City and two states (Georgia and Louisiana) experienced low ILI activity. The District of Columbia and 48 states experienced minimal ILI activity. Data was insufficient to calculate an ILI activity level from Puerto Rico. Additional data, including data for previous seasons, can be found at https://gis.cdc.gov/grasp/fluview/main.html
Geographic Spread of Influenza Viruses: Local influenza activity was reported by 5 states (Kentucky, Massachusetts, North Dakota, Oregon, and West Virginia). Sporadic activity was reported by the District of Columbia, Puerto Rico, the U.S. Virgin Islands and 43 states (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Louisiana, Maine, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, Wisconsin, and Wyoming). No influenza activity was reported by 2 states (Mississippi and Virginia). Guam did not report.
Geographic spread data show how many areas within a state or territory are seeing flu activity. Additional data are available at: https://gis.cdc.gov/grasp/fluview/FluView8.html.
Reporting of influenza-associated hospitalization data from the Influenza Hospitalization Surveillance Network (FluSurv-NET) for the 2018-2019 influenza season will begin later this season.
Additional data, including hospitalization rates during previous influenza seasons, can be found at http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.
The proportion of deaths attributed to pneumonia and influenza (P&I) was 5.4% during the week ending October 20, 2018 (week 42). This percentage is below the epidemic threshold of 6.0% for week 42 in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
Additional P&I mortality data for current and past seasons and by geography (national, HHS region, or state) are available at https://gis.cdc.gov/grasp/fluview/mortality.html.
Three influenza-associated pediatric deaths were reported to CDC during week 43.
One death was associated with an influenza A(H1N1)pdm09 virus and occurred during week 41 (the week ending October 13, 2018). A total of two influenza-associated pediatric deaths have been reported for the 2018-19 season.
An additional two influenza-associated pediatric deaths for the previous 2017-2018 flu season were also reported to CDC during week 43. One death was associated with an influenza B virus and one death was associated with an influenza A(H3) virus. These deaths bring the total number of reported influenza-associated deaths occurring during that season to 185.
Additional information on influenza-associated pediatric deaths reported during past seasons, including basic demographics, underlying conditions, bacterial co-infections, and place of death is available on FluView Interactive at: https://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html. More detailed information about pediatric deaths reported during the current season will be available later in the season.
Nationally, the percentage of respiratory specimens testing positive for influenza viruses in clinical laboratories during the week ending October 27 was 0.8%.
Regionally, the three week average percent of specimens testing positive for influenza in clinical laboratories ranged from 0.2% to 2.9%.
During the week ending October 27, of the 104 (0.8%) influenza-positive tests reported to CDC by clinical laboratories, 63 (60.6%) were influenza A viruses and 41 (39.4%) were influenza B viruses.
The most frequently identified influenza virus type reported by public health laboratories was influenza A(H1N1)pdm09 virus.
During the week ending October 27, 58 (82.9%) of the 70 influenza-positive tests reported to CDC by public health laboratories were influenza A viruses and 12 (17.1%) were influenza B viruses. Of the 50 influenza A viruses that were subtyped, 14 (28.0%) were H3N2 viruses and 36 (72.0%) were (H1N1)pdm09 viruses.
The majority of the influenza viruses collected from the United States during May 20 through October 27, 2018 were characterized antigenically and genetically as being similar to the cell-grown reference viruses representing the 2018–2019 Northern Hemisphere influenza vaccine viruses.
None of the viruses tested from May 20-October 27, 2018 were found to be resistant to oseltamivir, zanamivir, or peramivir. Antiviral resistance data will be updated weekly starting later in the season.