Updated Feb. 14, 2018
Influenza-associated hospitalizations in Pierce County continue to trend downward. Since Oct. 1, we received notification of 303 influenza-related hospitalizations. The median age of hospitalized patients is 67 years old; ages ranged from 2 weeks to 100 years old. In a medical record review, we found four people died shortly after discharge to hospice in January. This raises to 15 the total number of influenza-associated deaths in Pierce County. The median age of people who died is 69 years old; ages ranged from 44 to 102 years old. We have not received notification of a hospitalized patient’s influenza-associated death since Jan. 22.
Emergency department (ED) and urgent care visits for influenza-like illnesses (ILI) continue to trend upward. Between Oct. 1 and Feb. 3, reporting EDs and urgent care clinics saw 484 people for ILI. Of those, 133 (27%) were 5 to 24 years old and 157 (32%) were 25 to 49 years old.
We received notification of 17 influenza outbreaks in long-term care facilities.
For the week ending Feb. 3, we received notification of 611 positive influenza tests (27% of total tests).
These data are preliminary and subject to change.
Washington influenza activity remains elevated. For the week ending Feb. 3, ILI accounted for 3.3% of outpatient visits to ILI Surveillance Network participants, above the 1.1% state baseline. So far in the 2017-2018 season, the state received notification of 151 influenza-associated deaths and 134 outbreaks of ILI in long-term care facilities. For the week ending Feb. 3, 19.6% of state specimens tested by WHO/NREVSS were positive for influenza. The Centers for Disease Control and Prevention (CDC) characterized ILI activity in Washington as moderate and influenza activity as widespread.
U.S. influenza activity increased during the week ending Feb. 3. Influenza A H3N2 is the most commonly identified virus. For the week ending Feb. 3, the proportion of outpatient visits to ILI Surveillance Network participants was 7.7%, above the 2.2% national baseline. Sixty-three pediatric deaths have been reported for the 2017-2018 influenza season. For the week ending Jan. 20, the proportion of deaths attributable to pneumonia and influenza was 10.1%, above the epidemic threshold.
While much of the U.S. continues to experience high influenza activity, the 2017-2018 influenza season has been relatively moderate in Pierce County. In contrast, in the 2016-2017 influenza season, U.S. influenza activity was moderate and Western Washington influenza activity was high.
This time last year, we had received notification of 42 influenza deaths in Pierce County. By the end of the 2016-2017 influenza season, we had received notification of as many influenza deaths as in the three previous seasons combined.
Over the last three weeks, ED and urgent care visits for ILI have increased but the proportion of positive influenza B tests has increased in comparison to influenza A tests. We typically see this toward the end of influenza seasons. Although it appears the 2017-2018 influenza season has peaked in Pierce County, we anticipate several more weeks of elevated influenza activity.
Centers for Disease Control and Prevention. (Feb. 9, 2018). Weekly U.S. influenza surveillance report—www.cdc.gov/flu/weekly/index.htm.
Washington State Department of Health. (Feb. 9, 2018). Washington influenza update—www.doh.wa.gov/Portals/1/Documents/5100/420-100-FluUpdate.pdf.