Influenza Surveillance Update – Alicia Budd (CDC)
Alicia provided the influenza surveillance update for Week 43, ending October 27, 2018. Influenza activity in the United States remains low, although small increases in activity were reported. 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 27, 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) increased slightly to 1.7%, 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 and two states experienced low ILI activity; the District of Columbia and 48 states experienced minimal ILI activity; and Puerto Rico had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in five states was reported as local; the District of Columbia, Puerto Rico, the U.S. Virgin Islands and 43 states reported sporadic activity; two 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: Three influenza-associated pediatric deaths were reported to CDC. One occurred during the 2018-2019 season and two occurred during the 2017-2018 season.
A Summit partner asked for clarification on the percentage of deaths in children who were unvaccinated due to being too young. Following the call, Alicia shared the following response:
“I looked into your question about what % of the unvaccinated were due to being too young. When we calculate the % vaccinated, we are looking only at those who are eligible to receive vaccine (i.e., > 6 months) and those for whom we have vaccination status information available. Those too young to be vaccinated are not included in that calculation. During the past 3 seasons, the reported pediatric deaths that are 0–5 months of age has ranged from 6–12%, but this has consistently run at ~6.5% of all reported pediatric deaths in a given season.”
Announcements – L.J Tan (IAC)
- Summit Call Schedule – The Summit calls have resumed a weekly schedule. All calls take place on Thursdays at 3 p.m. ET. The next Summit call is scheduled for November 15.