- Influenza Surveillance Update – Alicia Budd (CDC)
- 2018–2019 Seasonal Influenza Update – John Donovan (CDC)
- Other Items – L.J Tan (IAC)
Influenza Surveillance Update – Alicia Budd (CDC)
Alicia provided an update on influenza activity reported for week 1, ending January 5, 2019. Influenza activity remains elevated across the country.
For the week, almost 13% of specimens sent to clinical laboratories tested positive for influenza. This is a slight decline from the 16% reported in the previous week. It is too soon to know whether this is an actual decrease in activity or whether the prior week’s reports were artificially elevated following delayed holiday reporting. CDC will continue to monitor this closely. Influenza A (H1) remains the predominant strain reported from public health labs and in 9 of the 10 surveillance regions. However, influenza H3 continues to be the predominant strain reported in Region 4 (southeastern states). The amount of reported influenza B circulating viruses continues to remain low at approximately 4% for the season as a whole. Of these, 60% of the viruses tested at public health labs have been of the Yamagata lineage. Most of the small numbers of B Victoria cases seen to date have been clustered in smaller areas, primarily in Maryland and Montana.
During this season, almost 450 viruses have received antigenic and genetic characterization. This data indicates the majority of viruses are similar to the reference viruses for this season’s vaccine components. In addition, none of the almost 500 viruses tested for resistance to oseltamivir, peramivir, and zanamivir has been found to be resistant.
Outpatient visits for influenza-like illness (ILI) decreased during the week to 3.5%, compared to just over 4% the previous week. This remains above the national baseline, and all 10 surveillance regions were above their region-specific baselines. On a state level, 15 states experienced high ILI levels, 12 states reported moderate activity, and the remaining 23 states were at low or minimal activity levels.
Cumulative reports to FluSurv-NET this season indicate a rate of 9.1/100,000 lab-confirmed influenza hospitalizations. Highest hospitalization rates were seen in persons >65 years at 22.9/100,000, followed by the 0–4 age group at 19.1/100,000.
The percent of deaths reported due to pneumonia and influenza (P&I) remained below the epidemic threshold, with 6.4% of deaths due to P&I.
Three new pediatric deaths were reported to CDC during the week. One death was from H1 infection, 1 was H3, and 1 was an influenza A virus infection which was not subtyped. A total of 16 pediatric deaths have been reported to CDC this season.
For the geographic spread of influenza during the week, 30 states reported widespread activity, 17 states reported regional activity, and 3 states reporting local or sporadic activity.
Alicia also discussed CDC’s new reporting on the preliminary in-season influenza burden estimates. Last week for the first time, these estimates were posted for the season to date. The estimates were derived from a mathematical model based on CDC’s lab-confirmed flu hospitalization surveillance data, the same methodology previously used to report disease burden estimates at the end of the season. CDC will now begin reporting these preliminary estimates during the season itself. Cumulative (October 1, 2018 through January 5, 2019) estimates of infection and illness in the U.S. indicate 6.2–7.3 million persons have been ill with influenza. In addition, 2.9–3.5 million persons have visited their healthcare provider due to illness, and 69,000–83,000 persons have been hospitalized. Flu-related mortality will be included in this report when levels are sufficient to provide reliable estimates. Alicia noted that these estimates will change each week because they are based on ongoing surveillance reports and are cumulative for the season. This new reporting data will be updated each Friday, at the same time as the weekly surveillance reports are released.
2018–2019 Seasonal Influenza Update – John Donovan (CDC)
John gave a presentation on the current influenza season, which has been relatively mild to date. Last year at this time the overall hospitalization rate was 30.5/100,000, while this year the rate has been a much lower 9.1/100,000. John reiterated the important messages for the year, including the concept that flu vaccines provide our best tool for prevention. Treatment with antivirals is also important; with the 2018 addition of Baloxavir Marboxil, there are now 4 antiviral medications available for treatment.
H1N1 is the predominant virus for the country, with the exception of the southeast, where H3N2 predominates. John also briefly mentioned the availability of the new in-season flu burden estimates. (See additional information in the Alicia Budd summary shown above.)
John reviewed additional CDC flu materials and activities, including National Influenza Vaccination Week (NIVW). Over 1,000 persons attended the NIVW webinar in December. This event provided information to assist healthcare providers in making a strong recommendation for influenza vaccination. Other resources include CDC’s Digital Campaign Toolkit, Communication Resource Center, and FluSight flu forecasting website. The latter facilitates real-time sharing and visualization of weekly flu forecasts. Recent information also is available on @CDCFlu. Finally, another helpful is the HealthMap Vaccine Finder.
Planning has already begun on communications for next flu season. Emphasis will be placed on having healthcare providers make strong recommendations using the SHARE approach.
Persons with questions may contact John Donovan at CDC.
Other Items – L.J Tan (IAC)
2019 Summit In-Person Meeting Information Now Available Online – The 2019 Summit in-person meeting will be held in Atlanta, GA on May 14–16, 2019. Information on registration, submission of poster abstracts, and nominations for the 2019 Immunization Excellence Awards is available on the 2019 National Adult and Influenza Immunization Summit webpage. (Please note that the password to register for this invitation-only meeting is available by contacting L.J Tan.) If possible, please book your room either through the onscreen “pop-up” that appears after you register or later through the email you receive after completing your registration. This not only will give you access to the “preferred rate,” it also will help the Summit meet its lodging contractual agreement with the hotel.