Oregon Public Health Division Published May 4, 2018 Oregon ESSENCE Syndromic Surveillance: Oregon Public Health tracks hospital emergency department (ED) visits throughout the state using the Oregon ESSENCE syndromic surveillance system. ESSENCE categorizes chief complaints into syndrome categories, which include influenza-like illness (ILI). Figure 1, above, displays percentages for all of Oregon during this flu season compared with the previous three flu seasons. Visits for ILI accounted for 1.1% of ED visits in all of Oregon during week 17 of 2018. Data at a Glance April 22 – April 28, 2018 (Week 17) Current Week (17) Previous Week (16) Percentage of emergency department visits for ILI 1 1.1% 1.3% Percentage positive influenza tests 2 8.2% 7.1% Influenza-associated hospitalizations 3 3 7 Reported ILI/influenza outbreaks 1 0 Influenza-associated pediatric deaths 0 0 Percentage of ILI at sentinel providers 4 0.39% 1.1% Respiratory Syncytial Virus (RSV) activity 5 — — 1 Influenza-like illness (ILI) data collected via Oregon ESSENCE Syndromic Surveillance. Data represent statewide aggregate percentage. 2 Data from Oregon labs reporting to the OHA and the National Respiratory and Enteric Virus Surveillance System (NREVSS). 3 Based on hospitalization surveillance in Clackamas, Multnomah, and Washington counties only. 4 Based on ILI reported by outpatient ILINet Sentinel Providers. 5 Percent positivity based on data from Oregon’s RSV Laboratory Surveillance System.
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Oregon Public Health Division Published May 4, 2018
Oregon ESSENCE Syndromic Surveillance:
Oregon Public Health tracks hospital emergency department (ED) visits throughout the state using the Oregon ESSENCE syndromic surveillance system. ESSENCE categorizes chief complaints into syndrome categories, which include influenza-like illness (ILI). Figure 1, above, displays percentages for all of Oregon during this flu season compared with the previous three flu seasons. Visits for ILI accounted for 1.1% of ED visits in all of Oregon during week 17 of 2018.
Data at a Glance April 22 – April 28, 2018 (Week 17)
Current Week (17) Previous Week (16)
Percentage of emergency department visits for ILI1 1.1% 1.3%
Percentage positive influenza tests2 8.2% 7.1%
Influenza-associated hospitalizations3 3 7
Reported ILI/influenza outbreaks 1 0
Influenza-associated pediatric deaths 0 0
Percentage of ILI at sentinel providers4
0.39% 1.1%
Respiratory Syncytial Virus (RSV) activity5 — —
1 Influenza-like illness (ILI) data collected via Oregon ESSENCE Syndromic Surveillance. Data represent statewide aggregate percentage. 2 Data from Oregon labs reporting to the OHA and the National Respiratory and Enteric Virus Surveillance System (NREVSS). 3 Based on hospitalization surveillance in Clackamas, Multnomah, and Washington counties only. 4 Based on ILI reported by outpatient ILINet Sentinel Providers. 5 Percent positivity based on data from Oregon’s RSV Laboratory Surveillance System.
Laboratory Surveillance:
The National Respiratory and Enteric Virus Surveillance System (NREVSS) is a laboratory-based system that monitors influenza and other respiratory viruses circulating in the United States. More information is at CDC’s website.
Table 1 shows the current week and cumulative totals (since October 1, 2017) for influenza in specimens tested at 25 Oregon laboratories contributing data to NREVSS and the state health department. Figure 2 shows that 8.2% of specimens tested at these Oregon labs were positive for influenza during week 17, and the chart displays the number of influenza-positive tests by flu type and percent positivity by week.
Table 1. Influenza Test Results in Oregon, NREVSS, 2017–2018 Season
Current Week Cumulative
No. of specimens tested 882 87,457
No. of positive specimens (%) 72 (8.2%) 19,337 (22.1%)
Hospitalizations: In Clackamas, Multnomah, and Washington counties, 3 influenza-associated hospitalizations were reported during week 17 of 2018, for a total of 1,562 cases reported during this season. For the season, 1,011(64.7%) cases were Flu A, 549 (35.2%) were flu B, and 1 was co-infected with flu A and B. Of 280 subtyped flu A cases, 131 (46.8%) were A/2009 H1N1 and 149 (53.2%) were A/H3N2. Of 131 sub-typed flu B cases, 130 (99.2%) were B/Yamagata and 1 (0.8%) was B/Victoria.
Age Group No. Cases %
<5 years 59 3.8
5-17 years 35 2.3
18-49 years 191 12.3
50-64 years 406 26.1
65+ years 863 55.5
Influenza-associated pediatric deaths: There have been a total of 3 influenza-associated pediatric deaths in Oregon during the 2017–2018 flu season.
Outbreak Update: There was one influenza-like illness outbreaks reported to the Oregon Health Authori-ty during week 17 of the 2017–2018 flu season. There have been a total of 142 influenza-like illness out-breaks reported this flu season, with 84% occurring in long-term care facilities and 10% occurring in schools.
ILINet: Oregon’s Outpatient Influenza-like Illness Surveillance Network: Oregon’s outpatient influen-za-like illness (ILI) network comprises 84 reporting facilities across Oregon. Facilities include 20 outpatient providers, 54 emergency departments and 10 urgent care clinics reporting to ESSENCE. Data are reported to CDC weekly. The percentage of outpatients seen with ILI for week 17 of 2018 was highest in the Central and Gorge and Portland Metro regions (both 1.2%) and lowest in the Eastern region (0.7%).
Map above: This map uses the proportion of outpatient visits to ILINet sentinel providers for influenza-like illness to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
US Data (from CDC FluView): During week 17 (April 22-28, 2018), influenza activity decreased in the United States. o Viral Surveillance: Overall, influenza A(H3) viruses have predominated this season. Since early March, influenza B viruses have been more frequently reported than influenza A viruses. The percentage of respir-atory specimens testing positive for influenza in clinical laboratories decreased. o 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) Mor-tality Surveillance System. o Influenza-associated Pediatric Deaths: Three influenza-associated pediatric deaths were reported. o Influenza-associated Hospitalizations: A cumulative rate of 106.0 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported. o Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.5%, which is below the national baseline of 2.2%. One of 10 regions reported ILI at or above their region-specific baseline level. Two states experienced low ILI activity; and New York City, the District of Columbia, Puerto Rico, and 48 states experienced minimal ILI activity. o Geographic Spread of Influenza: The geographic spread of influenza in three states was reported as widespread; Guam, Puerto Rico and seven states reported regional activity; 24 states reported local activi-ty; the District of Columbia, and 14 states reported sporadic activity; and the U.S. Virgin Islands and two states reported no influenza activity.
*Map left: This map measures the geographic spread of influ-enza viruses, but it does not measure the intensity of influen-za activity. All Flu Bites data provided are preliminary and may change as additional reports are received. Find the most recent report online at: www.healthoregon.org/fludata
